0.9-RC

Meta.stringList accepts nullable receiver.

.gitignore

@@ -5,5 +5,7 @@ out/
 .gradle
 build/
 
+.kotlin
+
 
 !gradle-wrapper.jar

CHANGELOG.md

@@ -3,17 +3,66 @@
 ## Unreleased
 
 ### Added
+- Custom CoroutineContext during `Context` creation.
 
 ### Changed
+- Kotlin 2.0
+- `MetaSpec` renamed to `MetaReader`. MetaSpec is now reserved for builder-based generation of meta descriptors.
+- Add self-type for Meta. Remove unsafe cast method for meta instances.
 
 ### Deprecated
 
 ### Removed
+- Automatic descriptors for schema. It is not possible to implement them without heavy reflection.
 
 ### Fixed
 
 ### Security
 
+## 0.8.2 - 2024-04-27
+
+### Added
+
+- Name index comparator
+- Specialized ByteArrayValue
+
+### Changed
+
+- DataSink `branch` is replaced with `putAll` to avoid confusion with DataTree methods
+- Meta delegate now uses a specific class that has a descriptor
+
+### Fixed
+
+- `listOfScheme` and `listOfConvertable` delegates provides correct items order.
+- Scheme meta setter works with proper sub-branch.
+- NameToken.parse improper work with indices.
+- Proper data handling for cache.
+
+## 0.8.0 - 2024-02-03
+
+### Added
+
+- Wasm artifacts
+- Add automatic MetaConverter for serializeable objects
+- Add Meta and MutableMeta delegates for convertable and serializeable
+- Meta mapping for data.
+
+### Changed
+
+- Descriptor `children` renamed to `nodes`
+- `MetaConverter` now inherits `MetaSpec` (former `Specifiction`). So `MetaConverter` could be used more universally.
+- Meta copy and modification now use lightweight non-observable meta builders.
+- Full refactor of Data API. DataTree now works similar to Meta: contains optional anonymous root element and data items. Updates are available for `ObservaleDataSource` and `ObservableDataTree` variants.
+
+### Deprecated
+
+- `node(key,converter)` in favor of `serializable` delegate
+
+### Fixed
+
+- Partially fixed a bug with `MutableMeta` observable wrappers.
+- `valueSequence` now include root value. So `meta.update` works properly.
+
 ## 0.7.0 - 2023-11-26
 
 ### Added

build.gradle.kts

@@ -3,20 +3,21 @@ import space.kscience.gradle.useApache2Licence
 import space.kscience.gradle.useSPCTeam
 
 plugins {
-    id("space.kscience.gradle.project")
+    alias(spclibs.plugins.kscience.project)
+    alias(spclibs.plugins.kotlinx.kover)
 }
 
 allprojects {
     group = "space.kscience"
-    version = "0.7.0"
+    version = "0.9.0-dev-1"
 }
 
 subprojects {
     apply(plugin = "maven-publish")
 
     tasks.withType<KotlinCompile> {
-        kotlinOptions {
-            freeCompilerArgs = freeCompilerArgs + "-Xcontext-receivers"
+        compilerOptions {
+            freeCompilerArgs.add("-Xcontext-receivers")
         }
     }
 }
@@ -30,8 +31,8 @@ ksciencePublish {
         useApache2Licence()
         useSPCTeam()
     }
-    repository("spc","https://maven.sciprog.center/kscience")
-    sonatype()
+    repository("spc", "https://maven.sciprog.center/kscience")
+    sonatype("https://oss.sonatype.org")
 }
 
 apiValidation {

dataforge-context/README.md

@@ -6,18 +6,16 @@ Context and provider definitions
 
 ## Artifact:
 
-The Maven coordinates of this project are `space.kscience:dataforge-context:0.7.0`.
+The Maven coordinates of this project are `space.kscience:dataforge-context:0.8.2`.
 
 **Gradle Kotlin DSL:**
 ```kotlin
 repositories {
     maven("https://repo.kotlin.link")
-    //uncomment to access development builds
-    //maven("https://maven.pkg.jetbrains.space/spc/p/sci/dev")
     mavenCentral()
 }
 
 dependencies {
-    implementation("space.kscience:dataforge-context:0.7.0")
+    implementation("space.kscience:dataforge-context:0.8.2")
 }
 ```

dataforge-context/api/dataforge-context.api

@@ -249,10 +249,25 @@ public final class space/kscience/dataforge/context/SlfLogManager$Companion : sp
 	public fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
 }
 
-public final class space/kscience/dataforge/properties/PropertyKt {
+public abstract interface annotation class space/kscience/dataforge/descriptors/Description : java/lang/annotation/Annotation {
+	public abstract fun value ()Ljava/lang/String;
 }
 
-public final class space/kscience/dataforge/properties/SchemePropertyKt {
+public abstract interface annotation class space/kscience/dataforge/descriptors/DescriptorResource : java/lang/annotation/Annotation {
+	public abstract fun resourceName ()Ljava/lang/String;
+}
+
+public abstract interface annotation class space/kscience/dataforge/descriptors/DescriptorUrl : java/lang/annotation/Annotation {
+	public abstract fun url ()Ljava/lang/String;
+}
+
+public abstract interface annotation class space/kscience/dataforge/descriptors/Multiple : java/lang/annotation/Annotation {
+}
+
+public final class space/kscience/dataforge/descriptors/ReflectiveDescriptorsKt {
+}
+
+public final class space/kscience/dataforge/properties/MetaAsFlowKt {
 }
 
 public final class space/kscience/dataforge/provider/DfTypeKt {

dataforge-context/build.gradle.kts

@@ -8,12 +8,14 @@ kscience {
     jvm()
     js()
     native()
+    wasm()
     useCoroutines()
     useSerialization()
-    dependencies {
-        api(project(":dataforge-meta"))
+    commonMain {
+        api(projects.dataforgeMeta)
+        api(spclibs.atomicfu)
     }
-    dependencies(jvmMain){
+    jvmMain{
         api(kotlin("reflect"))
         api("org.slf4j:slf4j-api:1.7.30")
     }

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/context/Context.kt

@@ -10,6 +10,7 @@ import space.kscience.dataforge.misc.ThreadSafe
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.provider.Provider
 import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
 
 /**
  * The local environment for anything being done in DataForge framework. Contexts are organized into tree structure with [Global] at the top.
@@ -26,6 +27,7 @@ public open class Context internal constructor(
     public val parent: Context?,
     plugins: Set<Plugin>, // set of unattached plugins
     meta: Meta,
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
 ) : Named, MetaRepr, Provider, CoroutineScope {
 
     /**
@@ -65,7 +67,7 @@ public open class Context internal constructor(
 
     override val coroutineContext: CoroutineContext by lazy {
         (parent ?: Global).coroutineContext.let { parenContext ->
-            parenContext + SupervisorJob(parenContext[Job])
+            parenContext + coroutineContext + SupervisorJob(parenContext[Job])
         }
     }
 

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/context/ContextBuilder.kt

@@ -13,6 +13,8 @@ import space.kscience.dataforge.names.plus
 import kotlin.collections.component1
 import kotlin.collections.component2
 import kotlin.collections.set
+import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
 
 /**
  * A convenience builder for context
@@ -59,8 +61,15 @@ public class ContextBuilder internal constructor(
         plugin(DeFactoPluginFactory(plugin))
     }
 
+    private var coroutineContext: CoroutineContext = EmptyCoroutineContext
+
+    public fun coroutineContext(coroutineContext: CoroutineContext) {
+        this.coroutineContext = coroutineContext
+    }
+
+
     public fun build(): Context {
-        val contextName = name ?: NameToken("@auto",hashCode().toUInt().toString(16)).asName()
+        val contextName = name ?: NameToken("@auto", hashCode().toUInt().toString(16)).asName()
         val plugins = HashMap<PluginTag, Plugin>()
 
         fun addPlugin(factory: PluginFactory<*>, meta: Meta) {
@@ -86,7 +95,7 @@ public class ContextBuilder internal constructor(
             addPlugin(factory, meta)
         }
 
-        return Context(contextName, parent, plugins.values.toSet(), meta.seal())
+        return Context(contextName, parent, plugins.values.toSet(), meta.seal(), coroutineContext)
     }
 }
 

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/context/Plugin.kt

@@ -3,7 +3,7 @@ package space.kscience.dataforge.context
 import space.kscience.dataforge.context.Plugin.Companion.TARGET
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.MetaRepr
-import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.DfType
 import space.kscience.dataforge.misc.Named
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.parseAsName
@@ -18,7 +18,7 @@ import space.kscience.dataforge.provider.Provider
  *
  * create - configure - attach - detach - destroy
  */
-@DfId(TARGET)
+@DfType(TARGET)
 public interface Plugin : Named, ContextAware, Provider, MetaRepr {
 
     /**

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/context/PluginFactory.kt

@@ -1,9 +1,9 @@
 package space.kscience.dataforge.context
 
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.DfType
 
-@DfId(PluginFactory.TYPE)
+@DfType(PluginFactory.TYPE)
 public interface PluginFactory<T : Plugin> : Factory<T> {
     public val tag: PluginTag
 

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/properties/MetaProperty.kt

@@ -1,35 +0,0 @@
-package space.kscience.dataforge.properties
-
-
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.ObservableMutableMeta
-import space.kscience.dataforge.meta.transformations.MetaConverter
-import space.kscience.dataforge.meta.transformations.nullableMetaToObject
-import space.kscience.dataforge.meta.transformations.nullableObjectToMeta
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.startsWith
-
-@DFExperimental
-public class MetaProperty<T : Any>(
-    public val meta: ObservableMutableMeta,
-    public val name: Name,
-    public val converter: MetaConverter<T>,
-) : Property<T?> {
-
-    override var value: T?
-        get() = converter.nullableMetaToObject(meta[name])
-        set(value) {
-            meta[name] = converter.nullableObjectToMeta(value) ?: Meta.EMPTY
-        }
-
-    override fun onChange(owner: Any?, callback: (T?) -> Unit) {
-        meta.onChange(owner) { name ->
-            if (name.startsWith(this@MetaProperty.name)) callback(converter.nullableMetaToObject(this[name]))
-        }
-    }
-
-    override fun removeChangeListener(owner: Any?) {
-        meta.removeListener(owner)
-    }
-}

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/properties/Property.kt

@@ -1,47 +0,0 @@
-package space.kscience.dataforge.properties
-
-import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.StateFlow
-import space.kscience.dataforge.misc.DFExperimental
-
-@DFExperimental
-public interface Property<T> {
-    public var value: T
-
-    public fun onChange(owner: Any? = null, callback: (T) -> Unit)
-    public fun removeChangeListener(owner: Any? = null)
-}
-
-@DFExperimental
-@OptIn(ExperimentalCoroutinesApi::class)
-public fun <T> Property<T>.toFlow(): StateFlow<T> = MutableStateFlow(value).also { stateFlow ->
-    onChange {
-        stateFlow.value = it
-    }
-}
-
-/**
- * Reflect all changes in the [source] property onto this property. Does not reflect changes back.
- *
- * @return a mirroring job
- */
-@DFExperimental
-public fun <T> Property<T>.mirror(source: Property<T>) {
-    source.onChange(this) {
-        this.value = it
-    }
-}
-
-/**
- * Bi-directional connection between properties
- */
-@DFExperimental
-public fun <T> Property<T>.bind(other: Property<T>) {
-    onChange(other) {
-        other.value = it
-    }
-    other.onChange {
-        this.value = it
-    }
-}

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/properties/metaAsFlow.kt

@@ -0,0 +1,51 @@
+package space.kscience.dataforge.properties
+
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.launch
+import space.kscience.dataforge.meta.*
+import space.kscience.dataforge.misc.DFExperimental
+
+@DFExperimental
+public fun <T> ObservableMeta.asFlow(converter: MetaReader<T>): Flow<T> = callbackFlow {
+    onChange(this){
+        trySend(converter.read(this))
+    }
+
+    awaitClose{
+        removeListener(this)
+    }
+}
+
+@DFExperimental
+public fun <T> MutableMeta.listenTo(
+    scope: CoroutineScope,
+    converter: MetaConverter<T>,
+    flow: Flow<T>,
+): Job = flow.onEach {
+    update(converter.convert(it))
+}.launchIn(scope)
+
+@DFExperimental
+public fun <T> ObservableMutableMeta.bind(
+    scope: CoroutineScope,
+    converter: MetaConverter<T>,
+    flow: MutableSharedFlow<T>,
+): Job = scope.launch{
+    listenTo(this, converter,flow)
+    onChange(flow){
+        launch {
+            flow.emit(converter.read(this@onChange))
+        }
+    }
+    flow.onCompletion {
+        removeListener(flow)
+    }
+}.also {
+    it.invokeOnCompletion {
+        removeListener(flow)
+    }
+}

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/properties/schemeProperty.kt

@@ -1,31 +0,0 @@
-package space.kscience.dataforge.properties
-
-
-import space.kscience.dataforge.meta.Scheme
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.parseAsName
-import space.kscience.dataforge.names.startsWith
-import kotlin.reflect.KMutableProperty1
-
-@DFExperimental
-public fun <S : Scheme, T : Any> S.property(property: KMutableProperty1<S, T?>): Property<T?> =
-    object : Property<T?> {
-        override var value: T?
-            get() = property.get(this@property)
-            set(value) {
-                property.set(this@property, value)
-            }
-
-        override fun onChange(owner: Any?, callback: (T?) -> Unit) {
-            this@property.meta.onChange(this) { name ->
-                if (name.startsWith(property.name.parseAsName(true))) {
-                    callback(property.get(this@property))
-                }
-            }
-        }
-
-        override fun removeChangeListener(owner: Any?) {
-            this@property.meta.removeListener(this@property)
-        }
-
-    }

dataforge-context/src/commonTest/kotlin/space/kscience/dataforge/properties/MetaPropertiesTest.kt

@@ -1,28 +0,0 @@
-package space.kscience.dataforge.properties
-
-import space.kscience.dataforge.meta.Scheme
-import space.kscience.dataforge.meta.SchemeSpec
-import space.kscience.dataforge.meta.int
-import space.kscience.dataforge.misc.DFExperimental
-import kotlin.test.Test
-import kotlin.test.assertEquals
-
-internal class TestScheme : Scheme() {
-    var a by int()
-    var b by int()
-    companion object : SchemeSpec<TestScheme>(::TestScheme)
-}
-
-@DFExperimental
-class MetaPropertiesTest {
-    @Test
-    fun testBinding() {
-        val scheme = TestScheme.empty()
-        val a = scheme.property(TestScheme::a)
-        val b = scheme.property(TestScheme::b)
-        a.bind(b)
-        scheme.a = 2
-        assertEquals(2, scheme.b)
-        assertEquals(2, b.value)
-    }
-}

dataforge-context/src/jsMain/kotlin/space/kscience/dataforge/properties/bindings.kt

@@ -1,32 +0,0 @@
-package space.kscience.dataforge.properties
-
-import org.w3c.dom.HTMLInputElement
-import space.kscience.dataforge.misc.DFExperimental
-
-@DFExperimental
-public fun HTMLInputElement.bindValue(property: Property<String>) {
-    if (this.onchange != null) error("Input element already bound")
-    this.onchange = {
-        property.value = this.value
-        Unit
-    }
-    property.onChange(this) {
-        if (value != it) {
-            value = it
-        }
-    }
-}
-
-@DFExperimental
-public fun HTMLInputElement.bindChecked(property: Property<Boolean>) {
-    if (this.onchange != null) error("Input element already bound")
-    this.onchange = {
-        property.value = this.checked
-        Unit
-    }
-    property.onChange(this) {
-        if (checked != it) {
-            checked = it
-        }
-    }
-}

dataforge-context/src/jvmMain/kotlin/space/kscience/dataforge/descriptors/annotations.kt

@@ -1,126 +0,0 @@
-/*
- * Copyright  2018 Alexander Nozik.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- */
-
-package space.kscience.dataforge.descriptors
-
-//@MustBeDocumented
-//annotation class Attribute(
-//    val key: String,
-//    val value: String
-//)
-//
-//@MustBeDocumented
-//annotation class Attributes(
-//    val attrs: Array<Attribute>
-//)
-//
-//@MustBeDocumented
-//annotation class ItemDef(
-//    val info: String = "",
-//    val multiple: Boolean = false,
-//    val required: Boolean = false
-//)
-//
-//@Target(AnnotationTarget.PROPERTY)
-//@MustBeDocumented
-//annotation class ValueDef(
-//    val type: Array<ValueType> = [ValueType.STRING],
-//    val def: String = "",
-//    val allowed: Array<String> = [],
-//    val enumeration: KClass<*> = Any::class
-//)
-
-///**
-// * Description text for meta property, node or whole object
-// */
-//@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class Description(val value: String)
-//
-///**
-// * Annotation for value property which states that lists are expected
-// */
-//@Target(AnnotationTarget.PROPERTY)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class Multiple
-//
-///**
-// * Descriptor target
-// * The DataForge path to the resource containing the description. Following targets are supported:
-// *  1. resource
-// *  1. file
-// *  1. class
-// *  1. method
-// *  1. property
-// *
-// *
-// * Does not work if [type] is provided
-// */
-//@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY, AnnotationTarget.VALUE_PARAMETER)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class Descriptor(val value: String)
-//
-//
-///**
-// * Aggregator class for descriptor nodes
-// */
-//@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY, AnnotationTarget.FUNCTION, AnnotationTarget.VALUE_PARAMETER)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class DescriptorNodes(vararg val nodes: NodeDef)
-//
-///**
-// * Aggregator class for descriptor values
-// */
-//@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY, AnnotationTarget.FUNCTION, AnnotationTarget.VALUE_PARAMETER)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class DescriptorValues(vararg val nodes: ValueDef)
-//
-///**
-// * Alternative name for property descriptor declaration
-// */
-//@Target(AnnotationTarget.PROPERTY, AnnotationTarget.VALUE_PARAMETER)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class DescriptorName(val name: String)
-//
-//@Target(AnnotationTarget.PROPERTY)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class DescriptorValue(val def: ValueDef)
-////TODO enter fields directly?
-//
-//@Target(AnnotationTarget.PROPERTY)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class ValueProperty(
-//    val name: String = "",
-//    val type: Array<ValueType> = arrayOf(ValueType.STRING),
-//    val multiple: Boolean = false,
-//    val def: String = "",
-//    val enumeration: KClass<*> = Any::class,
-//    val tags: Array<String> = emptyArray()
-//)
-//
-//
-//@Target(AnnotationTarget.PROPERTY)
-//@Retention(AnnotationRetention.RUNTIME)
-//@MustBeDocumented
-//annotation class NodeProperty(val name: String = "")

dataforge-context/src/jvmMain/kotlin/space/kscience/dataforge/descriptors/reflectiveDescriptors.kt

@@ -1,53 +1,132 @@
 package space.kscience.dataforge.descriptors
 
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.decodeFromStream
+import org.slf4j.LoggerFactory
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.meta.descriptors.MetaDescriptorBuilder
+import space.kscience.dataforge.misc.DFExperimental
+import java.net.URL
+import kotlin.reflect.KAnnotatedElement
+import kotlin.reflect.KProperty
 
-//inline fun <reified T : Scheme> T.buildDescriptor(): NodeDescriptor = NodeDescriptor {
-//    T::class.apply {
-//        findAnnotation<ItemDef>()?.let { def ->
-//            info = def.info
-//            required = def.required
-//            multiple = def.multiple
-//        }
-//        findAnnotation<Attribute>()?.let { attr ->
-//            attributes {
-//                this[attr.key] = attr.value.parseValue()
-//            }
-//        }
-//        findAnnotation<Attributes>()?.attrs?.forEach { attr ->
-//            attributes {
-//                this[attr.key] = attr.value.parseValue()
-//            }
-//        }
-//    }
-//    T::class.memberProperties.forEach { property ->
-//        val delegate = property.getDelegate(this@buildDescriptor)
+/**
+ * Description text for meta property, node or whole object
+ */
+@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY)
+@Retention(AnnotationRetention.RUNTIME)
+@MustBeDocumented
+public annotation class Description(val value: String)
+
+@Target(AnnotationTarget.PROPERTY)
+@Retention(AnnotationRetention.RUNTIME)
+@MustBeDocumented
+public annotation class Multiple()
+
+@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY)
+@Retention(AnnotationRetention.RUNTIME)
+@MustBeDocumented
+public annotation class DescriptorResource(val resourceName: String)
+
+@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY)
+@Retention(AnnotationRetention.RUNTIME)
+@MustBeDocumented
+public annotation class DescriptorUrl(val url: String)
+
+
+@OptIn(ExperimentalSerializationApi::class)
+private fun MetaDescriptorBuilder.loadDescriptorFromUrl(url: URL) {
+    url.openStream().use {
+        from(Json.decodeFromStream(MetaDescriptor.serializer(), it))
+    }
+}
+
+private fun MetaDescriptorBuilder.loadDescriptorFromResource(resource: DescriptorResource) {
+    val url = {}.javaClass.getResource(resource.resourceName)
+    if (url != null) {
+        loadDescriptorFromUrl(url)
+    } else {
+        LoggerFactory.getLogger("System")
+            .error("Can't find descriptor resource with name ${resource.resourceName}")
+    }
+}
+
+@DFExperimental
+public fun MetaDescriptorBuilder.forAnnotatedElement(element: KAnnotatedElement) {
+    element.annotations.forEach {
+        when (it) {
+            is Description -> description = it.value
+
+            is DescriptorResource -> loadDescriptorFromResource(it)
+
+            is DescriptorUrl -> loadDescriptorFromUrl(URL(it.url))
+        }
+    }
+}
+
+@DFExperimental
+public fun MetaDescriptorBuilder.forProperty(property: KProperty<*>) {
+    property.annotations.forEach {
+        when (it) {
+            is Description -> description = it.value
+
+            is DescriptorResource -> loadDescriptorFromResource(it)
+
+            is DescriptorUrl -> loadDescriptorFromUrl(URL(it.url))
+        }
+    }
+}
 //
-//        val descriptor: ItemDescriptor = when (delegate) {
-//            is ConfigurableDelegate -> buildPropertyDescriptor(property, delegate)
-//            is ReadWriteDelegateWrapper<*, *> -> {
-//                if (delegate.delegate is ConfigurableDelegate) {
-//                    buildPropertyDescriptor(property, delegate.delegate as ConfigurableDelegate)
-//                } else {
-//                    return@forEach
+//@DFExperimental
+//public fun <T : Scheme> MetaDescriptor.Companion.forScheme(
+//    spec: SchemeSpec<T>,
+//    mod: MetaDescriptorBuilder.() -> Unit = {},
+//): MetaDescriptor = MetaDescriptor {
+//    val scheme = spec.empty()
+//    val kClass: KClass<T> = scheme::class as KClass<T>
+//    when {
+//        kClass.isSubclassOf(Number::class) -> valueType(ValueType.NUMBER)
+//        kClass == String::class -> ValueType.STRING
+//        kClass == Boolean::class -> ValueType.BOOLEAN
+//        kClass == DoubleArray::class -> ValueType.LIST
+//        kClass == ByteArray::class -> ValueType.LIST
+//    }
+//
+//    forAnnotatedElement(kClass)
+//    kClass.memberProperties.forEach { property ->
+//        node(property.name) {
+//
+//            (property.getDelegate(scheme) as? MetaDelegate<*>)?.descriptor?.let {
+//                from(it)
+//            }
+//
+//            property.annotations.forEach {
+//                when (it) {
+//                    is Description -> {
+//                        description = it.value
+//                    }
+//
+//                    is Multiple -> {
+//                        multiple = true
+//                    }
+//
+//                    is DescriptorResource -> {
+//                        loadDescriptorFromResource(it)
+//                    }
+//
+//                    is DescriptorUrl -> {
+//                        loadDescriptorFromUrl(URL(it.url))
+//                    }
 //                }
 //            }
-//            else -> return@forEach
-//        }
-//        defineItem(property.name, descriptor)
-//    }
-//}
-
-//inline fun <T : Scheme, reified V : Any?> buildPropertyDescriptor(
-//    property: KProperty1<T, V>,
-//    delegate: ConfigurableDelegate
-//): ItemDescriptor {
-//    when {
-//        V::class.isSubclassOf(Scheme::class) -> NodeDescriptor {
-//            default = delegate.default.node
-//        }
-//        V::class.isSubclassOf(Meta::class) -> NodeDescriptor {
-//            default = delegate.default.node
 //        }
 //
 //    }
+//    mod()
 //}
+//
+//@DFExperimental
+//public inline fun <reified T : Scheme> SchemeSpec<T>.autoDescriptor(
+//    noinline mod: MetaDescriptorBuilder.() -> Unit = {},
+//): MetaDescriptor = MetaDescriptor.forScheme(this, mod)

dataforge-context/src/jvmMain/kotlin/space/kscience/dataforge/provider/dfType.kt

@@ -4,7 +4,7 @@ import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.context.PluginBuilder
 import space.kscience.dataforge.context.gather
 import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.DfType
 import space.kscience.dataforge.misc.Named
 import space.kscience.dataforge.names.Name
 import kotlin.reflect.KClass
@@ -12,21 +12,21 @@ import kotlin.reflect.full.findAnnotation
 
 
 @DFExperimental
-public val KClass<*>.dfId: String
-    get() = findAnnotation<DfId>()?.id ?: simpleName ?: ""
+public val KClass<*>.dfType: String
+    get() = findAnnotation<DfType>()?.id ?: simpleName ?: ""
 
 /**
- * Provide an object with given name inferring target from its type using [DfId] annotation
+ * Provide an object with given name inferring target from its type using [DfType] annotation
  */
 @DFExperimental
 public inline fun <reified T : Any> Provider.provideByType(name: String): T? {
-    val target = T::class.dfId
+    val target = T::class.dfType
     return provide(target, name)
 }
 
 @DFExperimental
 public inline fun <reified T : Any> Provider.top(): Map<Name, T> {
-    val target = T::class.dfId
+    val target = T::class.dfType
     return top(target)
 }
 
@@ -35,15 +35,15 @@ public inline fun <reified T : Any> Provider.top(): Map<Name, T> {
  */
 @DFExperimental
 public inline fun <reified T : Any> Context.gather(inherit: Boolean = true): Map<Name, T> =
-    gather<T>(T::class.dfId, inherit)
+    gather<T>(T::class.dfType, inherit)
 
 
 @DFExperimental
 public inline fun <reified T : Any> PluginBuilder.provides(items: Map<Name, T>) {
-    provides(T::class.dfId, items)
+    provides(T::class.dfType, items)
 }
 
 @DFExperimental
 public inline fun <reified T : Any> PluginBuilder.provides(vararg items: Named) {
-    provides(T::class.dfId, *items)
+    provides(T::class.dfType, *items)
 }

dataforge-context/src/jvmTest/kotlin/space/kscience/dataforge/descriptors/TestAutoDescriptors.kt

@@ -0,0 +1,29 @@
+@file:OptIn(DFExperimental::class)
+
+package space.kscience.dataforge.descriptors
+
+import space.kscience.dataforge.misc.DFExperimental
+
+//
+//class TestScheme : Scheme() {
+//
+//    @Description("A")
+//    val a by string()
+//
+//    @Description("B")
+//    val b by int()
+//
+//    val c by int()
+//
+//    companion object : SchemeSpec<TestScheme>(::TestScheme) {
+//        override val descriptor: MetaDescriptor = autoDescriptor()
+//    }
+//}
+//
+//class TestAutoDescriptors {
+//    @Test
+//    fun autoDescriptor() {
+//        val autoDescriptor = MetaDescriptor.forScheme(TestScheme)
+//        println(Json { prettyPrint = true }.encodeToString(autoDescriptor))
+//    }
+//}

dataforge-context/src/wasmJsMain/kotlin/space/kscience/dataforge/context/loggingWasm.kt

@@ -0,0 +1,3 @@
+package space.kscience.dataforge.context
+
+internal actual fun getGlobalLoggerFactory(): PluginFactory<out LogManager> = DefaultLogManager

dataforge-data/README.md

@@ -6,18 +6,16 @@
 
 ## Artifact:
 
-The Maven coordinates of this project are `space.kscience:dataforge-data:0.7.0`.
+The Maven coordinates of this project are `space.kscience:dataforge-data:0.8.2`.
 
 **Gradle Kotlin DSL:**
 ```kotlin
 repositories {
     maven("https://repo.kotlin.link")
-    //uncomment to access development builds
-    //maven("https://maven.pkg.jetbrains.space/spc/p/sci/dev")
     mavenCentral()
 }
 
 dependencies {
-    implementation("space.kscience:dataforge-data:0.7.0")
+    implementation("space.kscience:dataforge-data:0.8.2")
 }
 ```

dataforge-data/build.gradle.kts

@@ -6,9 +6,12 @@ kscience{
     jvm()
     js()
     native()
+    wasm()
     useCoroutines()
     dependencies {
-        api(project(":dataforge-meta"))
+        api(spclibs.atomicfu)
+        api(projects.dataforgeMeta)
+        //Remove after subtype moved to stdlib
         api(kotlin("reflect"))
     }
 }

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/actions/AbstractAction.kt

@@ -1,9 +1,14 @@
 package space.kscience.dataforge.actions
 
-import kotlinx.coroutines.launch
-import space.kscience.dataforge.data.*
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.onEach
+import space.kscience.dataforge.data.DataSink
+import space.kscience.dataforge.data.DataTree
+import space.kscience.dataforge.data.DataUpdate
+import space.kscience.dataforge.data.launchUpdate
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.misc.UnsafeKType
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.startsWith
 import kotlin.reflect.KType
@@ -19,47 +24,47 @@ internal fun MutableMap<Name, *>.removeWhatStartsWith(name: Name) {
 /**
  * An action that caches results on-demand and recalculates them on source push
  */
-public abstract class AbstractAction<in T : Any, R : Any>(
+public abstract class AbstractAction<T, R>(
     public val outputType: KType,
 ) : Action<T, R> {
 
     /**
      * Generate initial content of the output
      */
-    protected abstract fun DataSetBuilder<R>.generate(
-        data: DataSet<T>,
+    protected abstract fun DataSink<R>.generate(
+        source: DataTree<T>,
         meta: Meta,
     )
 
     /**
-     * Update part of the data set when given [updateKey] is triggered by the source
+     * Update part of the data set using provided data
+     *
+     * @param source the source data tree in case we need several data items to update
+     * @param meta the metadata used for the whole data tree
+     * @param updatedData an updated item
      */
-    protected open fun DataSourceBuilder<R>.update(
-        dataSet: DataSet<T>,
+    protected open suspend fun DataSink<R>.update(
+        source: DataTree<T>,
         meta: Meta,
-        updateKey: Name,
+        updatedData: DataUpdate<T>,
     ) {
-        // By default, recalculate the whole dataset
-        generate(dataSet, meta)
+        //by default regenerate the whole data set
+        generate(source, meta)
     }
 
-    @OptIn(DFInternal::class)
+    @OptIn(UnsafeKType::class)
     override fun execute(
-        dataSet: DataSet<T>,
+        source: DataTree<T>,
         meta: Meta,
-    ): DataSet<R> = if (dataSet is DataSource) {
-        DataSource(outputType, dataSet){
-            generate(dataSet, meta)
-
-            launch {
-                dataSet.updates.collect { name ->
-                    update(dataSet, meta, name)
-                }
-            }
-        }
-    } else {
-        DataTree<R>(outputType) {
-            generate(dataSet, meta)
+        updatesScope: CoroutineScope
+    ): DataTree<R> = DataTree(outputType) {
+        generate(source, meta)
+        //propagate updates
+        launchUpdate(updatesScope) {
+            source.updates.onEach { update ->
+                update(source, meta, update)
+            }.collect()
         }
     }
 }
+

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/actions/Action.kt

@@ -1,40 +1,50 @@
 package space.kscience.dataforge.actions
 
-import space.kscience.dataforge.data.DataSet
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.DelicateCoroutinesApi
+import kotlinx.coroutines.GlobalScope
+import space.kscience.dataforge.data.DataTree
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.misc.DFExperimental
 
 /**
  * A simple data transformation on a data node. Actions should avoid doing actual dependency evaluation in [execute].
  */
-public interface Action<in T : Any, out R : Any> {
+public fun interface Action<T, R> {
 
     /**
      * Transform the data in the node, producing a new node. By default, it is assumed that all calculations are lazy
      * so not actual computation is started at this moment.
      */
-    public fun execute(dataSet: DataSet<T>, meta: Meta = Meta.EMPTY): DataSet<R>
+    public fun execute(source: DataTree<T>, meta: Meta, updatesScope: CoroutineScope): DataTree<R>
 
     public companion object
 }
 
+/**
+ * A convenience method to transform data using given [action]
+ */
+@OptIn(DelicateCoroutinesApi::class)
+public fun <T, R> DataTree<T>.transform(
+    action: Action<T, R>,
+    meta: Meta = Meta.EMPTY,
+    updateScope: CoroutineScope = GlobalScope,
+): DataTree<R> = action.execute(this, meta, updateScope)
+
 /**
  * Action composition. The result is terminal if one of its parts is terminal
  */
-public infix fun <T : Any, I : Any, R : Any> Action<T, I>.then(action: Action<I, R>): Action<T, R> {
-    // TODO introduce composite action and add optimize by adding action to the list
-    return object : Action<T, R> {
-
-        override fun execute(
-            dataSet: DataSet<T>,
-            meta: Meta,
-        ): DataSet<R> = action.execute(this@then.execute(dataSet, meta), meta)
-    }
+public infix fun <T, I, R> Action<T, I>.then(action: Action<I, R>): Action<T, R> = Action { dataSet, meta, scope ->
+    action.execute(this@then.execute(dataSet, meta, scope), meta, scope)
 }
 
 @DFExperimental
-public operator fun <T : Any, R : Any> Action<T, R>.invoke(
-    dataSet: DataSet<T>,
+@OptIn(DelicateCoroutinesApi::class)
+public operator fun <T, R> Action<T, R>.invoke(
+    dataSet: DataTree<T>,
     meta: Meta = Meta.EMPTY,
-): DataSet<R> = execute(dataSet, meta)
+    updateScope: CoroutineScope = GlobalScope,
+): DataTree<R> = execute(dataSet, meta, updateScope)
+
+
 

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/actions/MapAction.kt

@@ -6,8 +6,7 @@ import space.kscience.dataforge.meta.MutableMeta
 import space.kscience.dataforge.meta.seal
 import space.kscience.dataforge.meta.toMutableMeta
 import space.kscience.dataforge.misc.DFBuilder
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.misc.UnsafeKType
 import space.kscience.dataforge.names.Name
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
@@ -29,6 +28,7 @@ public class MapActionBuilder<T, R>(
     public var name: Name,
     public var meta: MutableMeta,
     public val actionMeta: Meta,
+    public val dataType: KType,
     @PublishedApi internal var outputType: KType,
 ) {
 
@@ -45,19 +45,21 @@ public class MapActionBuilder<T, R>(
     /**
      * Calculate the result of goal
      */
-    public inline fun <reified R1 : R> result(noinline f: suspend ActionEnv.(T) -> R1) {
-        outputType = typeOf<R1>()
-        result = f;
-    }
+    public inline fun <reified R1 : R> result(noinline f: suspend ActionEnv.(T) -> R1): Unit = result(typeOf<R1>(), f)
 }
 
-@PublishedApi
-internal class MapAction<in T : Any, R : Any>(
+@UnsafeKType
+public class MapAction<T, R>(
     outputType: KType,
     private val block: MapActionBuilder<T, R>.() -> Unit,
 ) : AbstractAction<T, R>(outputType) {
 
-    private fun DataSetBuilder<R>.mapOne(name: Name, data: Data<T>, meta: Meta) {
+    private fun DataSink<R>.mapOne(name: Name, data: Data<T>?, meta: Meta) {
+        //fast return for null data
+        if (data == null) {
+            put(name, null)
+            return
+        }
         // Creating a new environment for action using **old** name, old meta and task meta
         val env = ActionEnv(name, data.meta, meta)
 
@@ -66,6 +68,7 @@ internal class MapAction<in T : Any, R : Any>(
             name,
             data.meta.toMutableMeta(), // using data meta
             meta,
+            data.type,
             outputType
         ).apply(block)
 
@@ -75,21 +78,25 @@ internal class MapAction<in T : Any, R : Any>(
         //getting new meta
         val newMeta = builder.meta.seal()
 
-        @OptIn(DFInternal::class)
         val newData = Data(builder.outputType, newMeta, dependencies = listOf(data)) {
             builder.result(env, data.await())
         }
         //setting the data node
-        data(newName, newData)
+        put(newName, newData)
     }
 
-    override fun DataSetBuilder<R>.generate(data: DataSet<T>, meta: Meta) {
-        data.forEach { mapOne(it.name, it.data, meta) }
+    override fun DataSink<R>.generate(source: DataTree<T>, meta: Meta) {
+        source.forEach { mapOne(it.name, it.data, meta) }
     }
 
-    override fun DataSourceBuilder<R>.update(dataSet: DataSet<T>, meta: Meta, updateKey: Name) {
-        remove(updateKey)
-        dataSet[updateKey]?.let { mapOne(updateKey, it, meta) }
+
+
+    override suspend fun DataSink<R>.update(
+        source: DataTree<T>,
+        meta: Meta,
+        updatedData: DataUpdate<T>,
+    )  {
+        mapOne(updatedData.name, updatedData.data, meta)
     }
 }
 
@@ -97,9 +104,9 @@ internal class MapAction<in T : Any, R : Any>(
 /**
  * A one-to-one mapping action
  */
-@DFExperimental
-@Suppress("FunctionName")
-public inline fun <T : Any, reified R : Any> Action.Companion.map(
+
+@OptIn(UnsafeKType::class)
+public inline fun <T, reified R> Action.Companion.mapping(
     noinline builder: MapActionBuilder<T, R>.() -> Unit,
 ): Action<T, R> = MapAction(typeOf<R>(), builder)
 

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/actions/ReduceAction.kt

@@ -4,17 +4,16 @@ import space.kscience.dataforge.data.*
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.MutableMeta
 import space.kscience.dataforge.misc.DFBuilder
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.misc.UnsafeKType
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.parseAsName
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
 
-public class JoinGroup<T : Any, R : Any>(
+public class JoinGroup<T, R>(
     public var name: String,
-    internal val set: DataSet<T>,
+    internal val set: DataTree<T>,
     @PublishedApi internal var outputType: KType,
 ) {
 
@@ -22,12 +21,12 @@ public class JoinGroup<T : Any, R : Any>(
 
     public lateinit var result: suspend ActionEnv.(Map<Name, ValueWithMeta<T>>) -> R
 
-    internal fun <R1 : R> result(outputType: KType, f: suspend ActionEnv.(Map<Name,  ValueWithMeta<T>>) -> R1) {
+    internal fun <R1 : R> result(outputType: KType, f: suspend ActionEnv.(Map<Name, ValueWithMeta<T>>) -> R1) {
         this.outputType = outputType
         this.result = f;
     }
 
-    public inline fun <reified R1 : R> result(noinline f: suspend ActionEnv.(Map<Name,  ValueWithMeta<T>>) -> R1) {
+    public inline fun <reified R1 : R> result(noinline f: suspend ActionEnv.(Map<Name, ValueWithMeta<T>>) -> R1) {
         outputType = typeOf<R1>()
         this.result = f;
     }
@@ -35,11 +34,11 @@ public class JoinGroup<T : Any, R : Any>(
 }
 
 @DFBuilder
-public class ReduceGroupBuilder<T : Any, R : Any>(
+public class ReduceGroupBuilder<T, R>(
     public val actionMeta: Meta,
     private val outputType: KType,
 ) {
-    private val groupRules: MutableList<(DataSet<T>) -> List<JoinGroup<T, R>>> = ArrayList();
+    private val groupRules: MutableList<(DataTree<T>) -> List<JoinGroup<T, R>>> = ArrayList();
 
     /**
      * introduce grouping by meta value
@@ -54,12 +53,12 @@ public class ReduceGroupBuilder<T : Any, R : Any>(
 
     public fun group(
         groupName: String,
-        predicate: (Name, Meta) -> Boolean,
+        predicate: DataFilter,
         action: JoinGroup<T, R>.() -> Unit,
     ) {
         groupRules += { source ->
             listOf(
-                JoinGroup<T, R>(groupName, source.filter(predicate), outputType).apply(action)
+                JoinGroup<T, R>(groupName, source.filterData(predicate), outputType).apply(action)
             )
         }
     }
@@ -67,26 +66,26 @@ public class ReduceGroupBuilder<T : Any, R : Any>(
     /**
      * Apply transformation to the whole node
      */
-    public fun result(resultName: String, f: suspend ActionEnv.(Map<Name,  ValueWithMeta<T>>) -> R) {
+    public fun result(resultName: String, f: suspend ActionEnv.(Map<Name, ValueWithMeta<T>>) -> R) {
         groupRules += { node ->
             listOf(JoinGroup<T, R>(resultName, node, outputType).apply { result(outputType, f) })
         }
     }
 
-    internal fun buildGroups(input: DataSet<T>): List<JoinGroup<T, R>> =
+    internal fun buildGroups(input: DataTree<T>): List<JoinGroup<T, R>> =
         groupRules.flatMap { it.invoke(input) }
 
 }
 
 @PublishedApi
-internal class ReduceAction<T : Any, R : Any>(
+internal class ReduceAction<T, R>(
     outputType: KType,
     private val action: ReduceGroupBuilder<T, R>.() -> Unit,
 ) : AbstractAction<T, R>(outputType) {
     //TODO optimize reduction. Currently, the whole action recalculates on push
 
-    override fun DataSetBuilder<R>.generate(data: DataSet<T>, meta: Meta) {
-        ReduceGroupBuilder<T, R>(meta, outputType).apply(action).buildGroups(data).forEach { group ->
+    override fun DataSink<R>.generate(source: DataTree<T>, meta: Meta) {
+        ReduceGroupBuilder<T, R>(meta, outputType).apply(action).buildGroups(source).forEach { group ->
             val dataFlow: Map<Name, Data<T>> = group.set.asSequence().fold(HashMap()) { acc, value ->
                 acc.apply {
                     acc[value.name] = value.data
@@ -98,12 +97,12 @@ internal class ReduceAction<T : Any, R : Any>(
             val groupMeta = group.meta
 
             val env = ActionEnv(groupName.parseAsName(), groupMeta, meta)
-            @OptIn(DFInternal::class) val res: Data<R> = dataFlow.reduceToData(
+            @OptIn(UnsafeKType::class) val res: Data<R> = dataFlow.reduceToData(
                 group.outputType,
                 meta = groupMeta
             ) { group.result.invoke(env, it) }
 
-            data(env.name, res)
+            put(env.name, res)
         }
     }
 }
@@ -111,7 +110,6 @@ internal class ReduceAction<T : Any, R : Any>(
 /**
  * A one-to-one mapping action
  */
-@DFExperimental
-public inline fun <reified T : Any, reified R : Any> Action.Companion.reduce(
+public inline fun <reified T, reified R> Action.Companion.reducing(
     noinline builder: ReduceGroupBuilder<T, R>.() -> Unit,
 ): Action<T, R> = ReduceAction(typeOf<R>(), builder)

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/actions/SplitAction.kt

@@ -5,7 +5,6 @@ import space.kscience.dataforge.meta.Laminate
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.MutableMeta
 import space.kscience.dataforge.meta.toMutableMeta
-import space.kscience.dataforge.misc.DFExperimental
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.parseAsName
 import kotlin.collections.set
@@ -13,9 +12,9 @@ import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
 
-public class SplitBuilder<T : Any, R : Any>(public val name: Name, public val meta: Meta) {
+public class SplitBuilder<T, R>(public val name: Name, public val meta: Meta) {
 
-    public class FragmentRule<T : Any, R : Any>(
+    public class FragmentRule<T, R>(
         public val name: Name,
         public var meta: MutableMeta,
         @PublishedApi internal var outputType: KType,
@@ -44,15 +43,15 @@ public class SplitBuilder<T : Any, R : Any>(public val name: Name, public val me
  * Action that splits each incoming element into a number of fragments defined in builder
  */
 @PublishedApi
-internal class SplitAction<T : Any, R : Any>(
+internal class SplitAction<T, R>(
     outputType: KType,
     private val action: SplitBuilder<T, R>.() -> Unit,
 ) : AbstractAction<T, R>(outputType) {
 
-    private fun DataSetBuilder<R>.splitOne(name: Name, data: Data<T>, meta: Meta) {
-        val laminate = Laminate(data.meta, meta)
+    private fun DataSink<R>.splitOne(name: Name, data: Data<T>?, meta: Meta) {
+        val laminate = Laminate(data?.meta, meta)
 
-        val split = SplitBuilder<T, R>(name, data.meta).apply(action)
+        val split = SplitBuilder<T, R>(name, data?.meta ?: Meta.EMPTY).apply(action)
 
 
         // apply individual fragment rules to result
@@ -64,29 +63,36 @@ internal class SplitAction<T : Any, R : Any>(
             ).apply(rule)
             //data.map<R>(outputType, meta = env.meta) { env.result(it) }.named(fragmentName)
 
-            data(
-                fragmentName,
-                @Suppress("OPT_IN_USAGE") Data(outputType, meta = env.meta, dependencies = listOf(data)) {
-                    env.result(data.await())
-                }
-            )
+            if (data == null) {
+                put(fragmentName, null)
+            } else {
+                put(
+                    fragmentName,
+                    @Suppress("OPT_IN_USAGE") Data(outputType, meta = env.meta, dependencies = listOf(data)) {
+                        env.result(data.await())
+                    }
+                )
+            }
         }
     }
 
-    override fun DataSetBuilder<R>.generate(data: DataSet<T>, meta: Meta) {
-        data.forEach { splitOne(it.name, it.data, meta) }
+    override fun DataSink<R>.generate(source: DataTree<T>, meta: Meta) {
+        source.forEach { splitOne(it.name, it.data, meta) }
     }
 
-    override fun DataSourceBuilder<R>.update(dataSet: DataSet<T>, meta: Meta, updateKey: Name) {
-        remove(updateKey)
-        dataSet[updateKey]?.let { splitOne(updateKey, it, meta) }
+    override suspend fun DataSink<R>.update(
+        source: DataTree<T>,
+        meta: Meta,
+        updatedData: DataUpdate<T>,
+    )  {
+        splitOne(updatedData.name, updatedData.data, meta)
     }
 }
 
 /**
  * Action that splits each incoming element into a number of fragments defined in builder
  */
-@DFExperimental
-public inline fun <T : Any, reified R : Any> Action.Companion.split(
+
+public inline fun <T, reified R> Action.Companion.splitting(
     noinline builder: SplitBuilder<T, R>.() -> Unit,
 ): Action<T, R> = SplitAction(typeOf<R>(), builder)

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/Data.kt

@@ -4,8 +4,8 @@ import kotlinx.coroutines.*
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.MetaRepr
 import space.kscience.dataforge.meta.isEmpty
-import space.kscience.dataforge.misc.DFInternal
-import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.DfType
+import space.kscience.dataforge.misc.UnsafeKType
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.EmptyCoroutineContext
 import kotlin.reflect.KType
@@ -14,7 +14,7 @@ import kotlin.reflect.typeOf
 /**
  * A data element characterized by its meta
  */
-@DfId(Data.TYPE)
+@DfType(Data.TYPE)
 public interface Data<out T> : Goal<T>, MetaRepr {
     /**
      * Type marker for the data. The type is known before the calculation takes place so it could be checked.
@@ -41,7 +41,7 @@ public interface Data<out T> : Goal<T>, MetaRepr {
          */
         internal val TYPE_OF_NOTHING: KType = typeOf<Unit>()
 
-        public inline fun <reified T : Any> static(
+        public inline fun <reified T> wrapValue(
             value: T,
             meta: Meta = Meta.EMPTY,
         ): Data<T> = StaticData(typeOf<T>(), value, meta)
@@ -50,10 +50,10 @@ public interface Data<out T> : Goal<T>, MetaRepr {
          * An empty data containing only meta
          */
         @OptIn(DelicateCoroutinesApi::class)
-        public fun empty(meta: Meta): Data<Nothing> = object : Data<Nothing> {
-            override val type: KType = TYPE_OF_NOTHING
+        public fun buildEmpty(meta: Meta): Data<Nothing> = object : Data<Nothing> {
+            override val type: KType get() = TYPE_OF_NOTHING
             override val meta: Meta = meta
-            override val dependencies: Collection<Goal<*>> = emptyList()
+            override val dependencies: Collection<Goal<*>> get() = emptyList()
             override val deferred: Deferred<Nothing>
                 get() = GlobalScope.async(start = CoroutineStart.LAZY) {
                     error("The Data is empty and could not be computed")
@@ -62,6 +62,8 @@ public interface Data<out T> : Goal<T>, MetaRepr {
             override fun async(coroutineScope: CoroutineScope): Deferred<Nothing> = deferred
             override fun reset() {}
         }
+
+        public val EMPTY: Data<Nothing> = buildEmpty(Meta.EMPTY)
     }
 }
 
@@ -69,39 +71,37 @@ public interface Data<out T> : Goal<T>, MetaRepr {
  * A lazily computed variant of [Data] based on [LazyGoal]
  * One must ensure that proper [type] is used so this method should not be used
  */
-private class LazyData<T : Any>(
+private class LazyData<T>(
     override val type: KType,
     override val meta: Meta = Meta.EMPTY,
     additionalContext: CoroutineContext = EmptyCoroutineContext,
-    dependencies: Collection<Goal<*>> = emptyList(),
+    dependencies: Iterable<Goal<*>> = emptyList(),
     block: suspend () -> T,
 ) : Data<T>, LazyGoal<T>(additionalContext, dependencies, block)
 
-public class StaticData<T : Any>(
+public class StaticData<T>(
     override val type: KType,
     value: T,
     override val meta: Meta = Meta.EMPTY,
 ) : Data<T>, StaticGoal<T>(value)
 
 @Suppress("FunctionName")
-public inline fun <reified T : Any> Data(value: T, meta: Meta = Meta.EMPTY): StaticData<T> =
+public inline fun <reified T> Data(value: T, meta: Meta = Meta.EMPTY): StaticData<T> =
     StaticData(typeOf<T>(), value, meta)
 
-@Suppress("FunctionName")
-@DFInternal
-public fun <T : Any> Data(
+@UnsafeKType
+public fun <T> Data(
     type: KType,
     meta: Meta = Meta.EMPTY,
     context: CoroutineContext = EmptyCoroutineContext,
-    dependencies: Collection<Goal<*>> = emptyList(),
+    dependencies: Iterable<Goal<*>> = emptyList(),
     block: suspend () -> T,
 ): Data<T> = LazyData(type, meta, context, dependencies, block)
 
-@OptIn(DFInternal::class)
-@Suppress("FunctionName")
-public inline fun <reified T : Any> Data(
+@OptIn(UnsafeKType::class)
+public inline fun <reified T> Data(
     meta: Meta = Meta.EMPTY,
     context: CoroutineContext = EmptyCoroutineContext,
-    dependencies: Collection<Goal<*>> = emptyList(),
+    dependencies: Iterable<Goal<*>> = emptyList(),
     noinline block: suspend () -> T,
 ): Data<T> = Data(typeOf<T>(), meta, context, dependencies, block)

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/DataFilter.kt

@@ -0,0 +1,110 @@
+package space.kscience.dataforge.data
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.filter
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.NameToken
+import space.kscience.dataforge.names.plus
+import kotlin.reflect.KType
+
+public fun interface DataFilter {
+
+    public fun accepts(name: Name, meta: Meta?, type: KType): Boolean
+
+    public companion object {
+        public val EMPTY: DataFilter = DataFilter { _, _, _ -> true }
+    }
+}
+
+
+public fun DataFilter.accepts(update: DataUpdate<*>): Boolean = accepts(update.name, update.data?.meta, update.type)
+
+public fun <T, DU : DataUpdate<T>> Sequence<DU>.filterData(predicate: DataFilter): Sequence<DU> = filter { data ->
+    predicate.accepts(data)
+}
+
+public fun <T, DU : DataUpdate<T>> Flow<DU>.filterData(predicate: DataFilter): Flow<DU> = filter { data ->
+    predicate.accepts(data)
+}
+
+public fun <T> DataSource<T>.filterData(
+    predicate: DataFilter,
+): DataSource<T> = object : DataSource<T> {
+    override val dataType: KType get() = this@filterData.dataType
+
+    override fun read(name: Name): Data<T>? =
+        this@filterData.read(name)?.takeIf { predicate.accepts(name, it.meta, it.type) }
+}
+
+/**
+ * Stateless filtered [ObservableDataSource]
+ */
+public fun <T> ObservableDataSource<T>.filterData(
+    predicate: DataFilter,
+): ObservableDataSource<T> = object : ObservableDataSource<T> {
+    override val updates: Flow<DataUpdate<T>>
+        get() = this@filterData.updates.filter { predicate.accepts(it) }
+
+    override val dataType: KType get() = this@filterData.dataType
+
+    override fun read(name: Name): Data<T>? =
+        this@filterData.read(name)?.takeIf { predicate.accepts(name, it.meta, it.type) }
+}
+
+internal class FilteredDataTree<T>(
+    val source: DataTree<T>,
+    val filter: DataFilter,
+    val branch: Name,
+    override val dataType: KType = source.dataType,
+) : DataTree<T> {
+
+    override val data: Data<T>?
+        get() = source[branch].takeIf {
+            filter.accepts(Name.EMPTY, it?.meta, it?.type ?: dataType)
+        }
+
+    override val items: Map<NameToken, DataTree<T>>
+        get() = source.branch(branch)?.items
+            ?.mapValues { FilteredDataTree(source, filter, branch + it.key) }
+            ?.filter { !it.value.isEmpty() }
+            ?: emptyMap()
+
+    override val updates: Flow<DataUpdate<T>>
+        get() = source.updates.filter { filter.accepts(it) }
+}
+
+
+public fun <T> DataTree<T>.filterData(
+    predicate: DataFilter,
+): DataTree<T> = FilteredDataTree(this, predicate, Name.EMPTY)
+
+
+///**
+// * Generate a wrapper data set with a given name prefix appended to all names
+// */
+//public fun <T : Any> DataTree<T>.withNamePrefix(prefix: Name): DataSet<T> = if (prefix.isEmpty()) {
+//    this
+//} else object : DataSource<T> {
+//
+//    override val dataType: KType get() = this@withNamePrefix.dataType
+//
+//    override val coroutineContext: CoroutineContext
+//        get() = (this@withNamePrefix as? DataSource)?.coroutineContext ?: EmptyCoroutineContext
+//
+//    override val meta: Meta get() = this@withNamePrefix.meta
+//
+//
+//    override fun iterator(): Iterator<NamedData<T>> = iterator {
+//        for (d in this@withNamePrefix) {
+//            yield(d.data.named(prefix + d.name))
+//        }
+//    }
+//
+//    override fun get(name: Name): Data<T>? =
+//        name.removeFirstOrNull(name)?.let { this@withNamePrefix.get(it) }
+//
+//    override val updates: Flow<Name> get() = this@withNamePrefix.updates.map { prefix + it }
+//}
+//
+

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/DataSet.kt

@@ -1,124 +0,0 @@
-package space.kscience.dataforge.data
-
-import kotlinx.coroutines.*
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.emptyFlow
-import kotlinx.coroutines.flow.mapNotNull
-import space.kscience.dataforge.data.Data.Companion.TYPE_OF_NOTHING
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.asName
-import space.kscience.dataforge.names.endsWith
-import space.kscience.dataforge.names.parseAsName
-import kotlin.reflect.KType
-
-public interface DataSet<out T : Any> {
-
-    /**
-     * The minimal common ancestor to all data in the node
-     */
-    public val dataType: KType
-
-    /**
-     * Meta-data associated with this node. If no meta is provided, returns [Meta.EMPTY].
-     */
-    public val meta: Meta
-
-    /**
-     * Traverse this [DataSet] returning named data instances. The order is not guaranteed.
-     */
-    public operator fun iterator(): Iterator<NamedData<T>>
-
-    /**
-     * Get data with given name.
-     */
-    public operator fun get(name: Name): Data<T>?
-
-    public companion object {
-        public val META_KEY: Name = "@meta".asName()
-
-        /**
-         * An empty [DataSet] that suits all types
-         */
-        public val EMPTY: DataSet<Nothing> = object : DataSet<Nothing> {
-            override val dataType: KType = TYPE_OF_NOTHING
-            override val meta: Meta get() = Meta.EMPTY
-
-            override fun iterator(): Iterator<NamedData<Nothing>> = emptySequence<NamedData<Nothing>>().iterator()
-
-            override fun get(name: Name): Data<Nothing>? = null
-        }
-    }
-}
-
-public fun <T : Any> DataSet<T>.asSequence(): Sequence<NamedData<T>> = object : Sequence<NamedData<T>> {
-    override fun iterator(): Iterator<NamedData<T>> = this@asSequence.iterator()
-}
-
-/**
- * Return a single [Data] in this [DataSet]. Throw error if it is not single.
- */
-public fun <T : Any> DataSet<T>.single(): NamedData<T> = asSequence().single()
-
-public fun <T : Any> DataSet<T>.asIterable(): Iterable<NamedData<T>> = object : Iterable<NamedData<T>> {
-    override fun iterator(): Iterator<NamedData<T>> = this@asIterable.iterator()
-}
-
-public operator fun <T : Any> DataSet<T>.get(name: String): Data<T>? = get(name.parseAsName())
-
-/**
- * A [DataSet] with propagated updates.
- */
-public interface DataSource<out T : Any> : DataSet<T>, CoroutineScope {
-
-    /**
-     * A flow of updated item names. Updates are propagated in a form of [Flow] of names of updated nodes.
-     * Those can include new data items and replacement of existing ones. The replaced items could update existing data content
-     * and replace it completely, so they should be pulled again.
-     *
-     */
-    public val updates: Flow<Name>
-
-    /**
-     * Stop generating updates from this [DataSource]
-     */
-    public fun close() {
-        coroutineContext[Job]?.cancel()
-    }
-}
-
-public val <T : Any> DataSet<T>.updates: Flow<Name> get() = if (this is DataSource) updates else emptyFlow()
-//
-///**
-// * Flow all data nodes with names starting with [branchName]
-// */
-//public fun <T : Any> DataSet<T>.children(branchName: Name): Sequence<NamedData<T>> =
-//    this@children.asSequence().filter {
-//        it.name.startsWith(branchName)
-//    }
-
-/**
- * Start computation for all goals in data node and return a job for the whole node
- */
-public fun <T : Any> DataSet<T>.startAll(coroutineScope: CoroutineScope): Job = coroutineScope.launch {
-    asIterable().map {
-        it.launch(this@launch)
-    }.joinAll()
-}
-
-public suspend fun <T : Any> DataSet<T>.computeAndJoinAll(): Unit = coroutineScope { startAll(this).join() }
-
-public fun DataSet<*>.toMeta(): Meta = Meta {
-    forEach {
-        if (it.name.endsWith(DataSet.META_KEY)) {
-            set(it.name, it.meta)
-        } else {
-            it.name put {
-                "type" put it.type.toString()
-                "meta" put it.meta
-            }
-        }
-    }
-}
-
-public val <T : Any> DataSet<T>.updatesWithData: Flow<NamedData<T>> get() = updates.mapNotNull { get(it)?.named(it) }

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/DataSetBuilder.kt

@@ -1,165 +0,0 @@
-package space.kscience.dataforge.data
-
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MutableMeta
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.isEmpty
-import space.kscience.dataforge.names.plus
-import kotlin.reflect.KType
-
-public interface DataSetBuilder<in T : Any> {
-    public val dataType: KType
-
-    /**
-     * Remove all data items starting with [name]
-     */
-    public fun remove(name: Name)
-
-    public fun data(name: Name, data: Data<T>?)
-
-    /**
-     * Set a current state of given [dataSet] into a branch [name]. Does not propagate updates
-     */
-    public fun node(name: Name, dataSet: DataSet<T>) {
-        //remove previous items
-        if (name != Name.EMPTY) {
-            remove(name)
-        }
-
-        //Set new items
-        dataSet.forEach {
-            data(name + it.name, it.data)
-        }
-    }
-
-    /**
-     * Set meta for the given node
-     */
-    public fun meta(name: Name, meta: Meta)
-
-}
-
-/**
- * Define meta in this [DataSet]
- */
-public fun <T : Any> DataSetBuilder<T>.meta(value: Meta): Unit = meta(Name.EMPTY, value)
-
-/**
- * Define meta in this [DataSet]
- */
-public fun <T : Any> DataSetBuilder<T>.meta(mutableMeta: MutableMeta.() -> Unit): Unit = meta(Meta(mutableMeta))
-
-@PublishedApi
-internal class SubSetBuilder<in T : Any>(
-    private val parent: DataSetBuilder<T>,
-    private val branch: Name,
-) : DataSetBuilder<T> {
-    override val dataType: KType get() = parent.dataType
-
-    override fun remove(name: Name) {
-        parent.remove(branch + name)
-    }
-
-    override fun data(name: Name, data: Data<T>?) {
-        parent.data(branch + name, data)
-    }
-
-    override fun node(name: Name, dataSet: DataSet<T>) {
-        parent.node(branch + name, dataSet)
-    }
-
-    override fun meta(name: Name, meta: Meta) {
-        parent.meta(branch + name, meta)
-    }
-}
-
-public inline fun <T : Any> DataSetBuilder<T>.node(
-    name: Name,
-    crossinline block: DataSetBuilder<T>.() -> Unit,
-) {
-    if (name.isEmpty()) block() else SubSetBuilder(this, name).block()
-}
-
-
-public fun <T : Any> DataSetBuilder<T>.data(name: String, value: Data<T>) {
-    data(Name.parse(name), value)
-}
-
-public fun <T : Any> DataSetBuilder<T>.node(name: String, set: DataSet<T>) {
-    node(Name.parse(name), set)
-}
-
-public inline fun <T : Any> DataSetBuilder<T>.node(
-    name: String,
-    crossinline block: DataSetBuilder<T>.() -> Unit,
-): Unit = node(Name.parse(name), block)
-
-public fun <T : Any> DataSetBuilder<T>.set(value: NamedData<T>) {
-    data(value.name, value.data)
-}
-
-/**
- * Produce lazy [Data] and emit it into the [DataSetBuilder]
- */
-public inline fun <reified T : Any> DataSetBuilder<T>.produce(
-    name: String,
-    meta: Meta = Meta.EMPTY,
-    noinline producer: suspend () -> T,
-) {
-    val data = Data(meta, block = producer)
-    data(name, data)
-}
-
-public inline fun <reified T : Any> DataSetBuilder<T>.produce(
-    name: Name,
-    meta: Meta = Meta.EMPTY,
-    noinline producer: suspend () -> T,
-) {
-    val data = Data(meta, block = producer)
-    data(name, data)
-}
-
-/**
- * Emit a static data with the fixed value
- */
-public inline fun <reified T : Any> DataSetBuilder<T>.static(
-    name: String,
-    data: T,
-    meta: Meta = Meta.EMPTY,
-): Unit = data(name, Data.static(data, meta))
-
-public inline fun <reified T : Any> DataSetBuilder<T>.static(
-    name: Name,
-    data: T,
-    meta: Meta = Meta.EMPTY,
-): Unit = data(name, Data.static(data, meta))
-
-public inline fun <reified T : Any> DataSetBuilder<T>.static(
-    name: String,
-    data: T,
-    mutableMeta: MutableMeta.() -> Unit,
-): Unit = data(Name.parse(name), Data.static(data, Meta(mutableMeta)))
-
-/**
- * Update data with given node data and meta with node meta.
- */
-@DFExperimental
-public fun <T : Any> DataSetBuilder<T>.populateFrom(tree: DataSet<T>): Unit {
-    tree.forEach {
-        //TODO check if the place is occupied
-        data(it.name, it.data)
-    }
-}
-
-//public fun <T : Any> DataSetBuilder<T>.populateFrom(flow: Flow<NamedData<T>>) {
-//    flow.collect {
-//        data(it.name, it.data)
-//    }
-//}
-
-public fun <T : Any> DataSetBuilder<T>.populateFrom(sequence: Sequence<NamedData<T>>) {
-    sequence.forEach {
-        data(it.name, it.data)
-    }
-}

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/DataSink.kt

@@ -0,0 +1,159 @@
+package space.kscience.dataforge.data
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.mapNotNull
+import kotlinx.coroutines.launch
+import space.kscience.dataforge.misc.UnsafeKType
+import space.kscience.dataforge.names.*
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
+
+public interface DataSink<in T> {
+    /**
+     * Put data without notification
+     */
+    public fun put(name: Name, data: Data<T>?)
+
+    /**
+     * Put data and propagate changes downstream
+     */
+    public suspend fun update(name: Name, data: Data<T>?)
+}
+
+/**
+ * Launch continuous update using
+ */
+public fun <T> DataSink<T>.launchUpdate(
+    scope: CoroutineScope,
+    updater: suspend DataSink<T>.() -> Unit,
+): Job = scope.launch {
+    object : DataSink<T> {
+        override fun put(name: Name, data: Data<T>?) {
+            launch {
+                this@launchUpdate.update(name, data)
+            }
+        }
+
+        override suspend fun update(name: Name, data: Data<T>?) {
+            this@launchUpdate.update(name, data)
+        }
+    }.updater()
+}
+
+/**
+ * A mutable version of [DataTree]
+ */
+public interface MutableDataTree<T> : DataTree<T>, DataSink<T> {
+    override var data: Data<T>?
+
+    override val items: Map<NameToken, MutableDataTree<T>>
+
+    public fun getOrCreateItem(token: NameToken): MutableDataTree<T>
+
+    public operator fun set(token: NameToken, data: Data<T>?)
+
+    override fun put(name: Name, data: Data<T>?): Unit = set(name, data)
+}
+
+public tailrec operator fun <T> MutableDataTree<T>.set(name: Name, data: Data<T>?): Unit {
+    when (name.length) {
+        0 -> this.data = data
+        1 -> set(name.first(), data)
+        else -> getOrCreateItem(name.first())[name.cutFirst()] = data
+    }
+}
+
+/**
+ * Provide a mutable subtree if it exists
+ */
+public tailrec fun <T> MutableDataTree<T>.branch(name: Name): MutableDataTree<T>? =
+    when (name.length) {
+        0 -> this
+        1 -> items[name.first()]
+        else -> items[name.first()]?.branch(name.cutFirst())
+    }
+
+private class MutableDataTreeRoot<T>(
+    override val dataType: KType,
+) : MutableDataTree<T> {
+
+    override val updates = MutableSharedFlow<DataUpdate<T>>(100, onBufferOverflow = BufferOverflow.DROP_LATEST)
+
+
+    inner class MutableDataTreeBranch(val branchName: Name) : MutableDataTree<T> {
+
+        override var data: Data<T>? = null
+
+        override val items = HashMap<NameToken, MutableDataTree<T>>()
+
+        override val updates: Flow<DataUpdate<T>> = this@MutableDataTreeRoot.updates.mapNotNull { update ->
+            update.name.removeFirstOrNull(branchName)?.let {
+                DataUpdate(update.data?.type ?: dataType, it, update.data)
+            }
+        }
+        override val dataType: KType get() = this@MutableDataTreeRoot.dataType
+
+
+        override fun getOrCreateItem(token: NameToken): MutableDataTree<T> =
+            items.getOrPut(token) { MutableDataTreeBranch(branchName + token) }
+
+
+        override fun set(token: NameToken, data: Data<T>?) {
+            val subTree = getOrCreateItem(token)
+            subTree.data = data
+        }
+
+        override suspend fun update(name: Name, data: Data<T>?) {
+            if (name.isEmpty()) {
+                this.data = data
+                this@MutableDataTreeRoot.updates.emit(DataUpdate(data?.type ?: dataType, branchName + name, data))
+            } else {
+                getOrCreateItem(name.first()).update(name.cutFirst(), data)
+            }
+        }
+
+    }
+
+
+    override var data: Data<T>? = null
+
+    override val items = HashMap<NameToken, MutableDataTree<T>>()
+
+    override fun getOrCreateItem(token: NameToken): MutableDataTree<T> = items.getOrPut(token) {
+        MutableDataTreeBranch(token.asName())
+    }
+
+    override fun set(token: NameToken, data: Data<T>?) {
+        val subTree = getOrCreateItem(token)
+        subTree.data = data
+    }
+
+    override suspend fun update(name: Name, data: Data<T>?) {
+        if (name.isEmpty()) {
+            this.data = data
+            updates.emit(DataUpdate(data?.type ?: dataType, name, data))
+        } else {
+            getOrCreateItem(name.first()).update(name.cutFirst(), data)
+        }
+    }
+}
+
+/**
+ * Create a new [MutableDataTree]
+ */
+@UnsafeKType
+public fun <T> MutableDataTree(
+    type: KType,
+): MutableDataTree<T> = MutableDataTreeRoot<T>(type)
+
+/**
+ * Create and initialize a observable mutable data tree.
+ */
+@OptIn(UnsafeKType::class)
+public inline fun <reified T> MutableDataTree(
+    generator: MutableDataTree<T>.() -> Unit = {},
+): MutableDataTree<T> = MutableDataTree<T>(typeOf<T>()).apply { generator() }

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/DataSource.kt

@@ -0,0 +1,131 @@
+package space.kscience.dataforge.data
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.emptyFlow
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.names.*
+import kotlin.contracts.contract
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
+
+/**
+ * A generic data provider
+ */
+public interface DataSource<out T> {
+
+    /**
+     * The minimal common ancestor to all data in the node
+     */
+    public val dataType: KType
+
+    /**
+     * Get data with given name. Or null if it is not present
+     */
+    public fun read(name: Name): Data<T>?
+}
+
+/**
+ * A data provider with possible dynamic updates
+ */
+public interface ObservableDataSource<out T> : DataSource<T> {
+
+    /**
+     * Flow updates made to the data
+     */
+    public val updates: Flow<DataUpdate<T>>
+}
+
+/**
+ * A tree like structure for data holding
+ */
+public interface DataTree<out T> : ObservableDataSource<T> {
+
+    public val data: Data<T>?
+    public val items: Map<NameToken, DataTree<T>>
+
+    override fun read(name: Name): Data<T>? = when (name.length) {
+        0 -> data
+        else -> items[name.first()]?.read(name.cutFirst())
+    }
+
+    /**
+     * Flow updates made to the data
+     */
+    override val updates: Flow<DataUpdate<T>>
+
+    public companion object {
+        private object EmptyDataTree :
+            DataTree<Nothing> {
+            override val data: Data<Nothing>? = null
+            override val items: Map<NameToken, EmptyDataTree> = emptyMap()
+            override val dataType: KType = typeOf<Unit>()
+
+            override fun read(name: Name): Data<Nothing>? = null
+            override val updates: Flow<DataUpdate<Nothing>> get() = emptyFlow()
+        }
+
+        public val EMPTY: DataTree<Nothing> = EmptyDataTree
+    }
+}
+
+/**
+ * An alias for easier access to tree values
+ */
+public operator fun <T> DataTree<T>.get(name: Name): Data<T>? = read(name)
+
+public operator fun <T> DataTree<T>.get(name: String): Data<T>? = read(name.parseAsName())
+
+/**
+ * Return a sequence of all data items in this tree.
+ * This method does not take updates into account.
+ */
+public fun <T> DataTree<T>.asSequence(
+    namePrefix: Name = Name.EMPTY,
+): Sequence<NamedData<T>> = sequence {
+    data?.let { yield(it.named(namePrefix)) }
+    items.forEach { (token, tree) ->
+        yieldAll(tree.asSequence(namePrefix + token))
+    }
+}
+
+/**
+ * Walk the data tree depth-first.
+ *
+ * @return a [Sequence] of pairs [Name]-[DataTree] for all nodes including the root one.
+ */
+public fun <T> DataTree<T>.walk(
+    namePrefix: Name = Name.EMPTY,
+): Sequence<Pair<Name, DataTree<T>>> = sequence {
+    yield(namePrefix to this@walk)
+    items.forEach { (token, tree) ->
+        yieldAll(tree.walk(namePrefix + token))
+    }
+}
+
+public val DataTree<*>.meta: Meta? get() = data?.meta
+
+/**
+ * Provide subtree if it exists
+ */
+public tailrec fun <T> DataTree<T>.branch(name: Name): DataTree<T>? =
+    when (name.length) {
+        0 -> this
+        1 -> items[name.first()]
+        else -> items[name.first()]?.branch(name.cutFirst())
+    }
+
+public fun <T> DataTree<T>.branch(name: String): DataTree<T>? =
+    branch(name.parseAsName())
+
+public fun DataTree<*>.isEmpty(): Boolean = data == null && items.isEmpty()
+
+/**
+ * Check if the [DataTree] is observable
+ */
+public fun <T> DataSource<T>.isObservable(): Boolean {
+    contract {
+        returns(true) implies (this@isObservable is ObservableDataSource<T>)
+    }
+    return this is ObservableDataSource<T>
+}
+

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/DataTree.kt

@@ -1,119 +0,0 @@
-package space.kscience.dataforge.data
-
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFInternal
-import space.kscience.dataforge.misc.DfId
-import space.kscience.dataforge.names.*
-import kotlin.collections.component1
-import kotlin.collections.component2
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
-
-public sealed class DataTreeItem<out T : Any> {
-
-    public abstract val meta: Meta
-
-    public class Node<out T : Any>(public val tree: DataTree<T>) : DataTreeItem<T>() {
-        override val meta: Meta get() = tree.meta
-    }
-
-    public class Leaf<out T : Any>(public val data: Data<T>) : DataTreeItem<T>() {
-        override val meta: Meta get() = data.meta
-    }
-}
-
-public val <T : Any> DataTreeItem<T>.type: KType
-    get() = when (this) {
-        is DataTreeItem.Node -> tree.dataType
-        is DataTreeItem.Leaf -> data.type
-    }
-
-/**
- * A tree-like [DataSet] grouped into the node. All data inside the node must inherit its type
- */
-@DfId(DataTree.TYPE)
-public interface DataTree<out T : Any> : DataSet<T> {
-
-    /**
-     * Top-level children items of this [DataTree]
-     */
-    public val items: Map<NameToken, DataTreeItem<T>>
-
-    override val meta: Meta get() = items[META_ITEM_NAME_TOKEN]?.meta ?: Meta.EMPTY
-
-    override fun iterator(): Iterator<NamedData<T>> = iterator {
-        items.forEach { (token, childItem: DataTreeItem<T>) ->
-            if (!token.body.startsWith("@")) {
-                when (childItem) {
-                    is DataTreeItem.Leaf -> yield(childItem.data.named(token.asName()))
-                    is DataTreeItem.Node -> yieldAll(childItem.tree.asSequence().map { it.named(token + it.name) })
-                }
-            }
-        }
-    }
-
-    override fun get(name: Name): Data<T>? = when (name.length) {
-        0 -> null
-        1 -> items[name.firstOrNull()!!].data
-        else -> items[name.firstOrNull()!!].tree?.get(name.cutFirst())
-    }
-
-    public companion object {
-        public const val TYPE: String = "dataTree"
-
-        /**
-         * A name token used to designate tree node meta
-         */
-        public val META_ITEM_NAME_TOKEN: NameToken = NameToken("@meta")
-
-        @DFInternal
-        public fun <T : Any> emptyWithType(type: KType, meta: Meta = Meta.EMPTY): DataTree<T> = object : DataTree<T> {
-            override val items: Map<NameToken, DataTreeItem<T>> get() = emptyMap()
-            override val dataType: KType get() = type
-            override val meta: Meta get() = meta
-        }
-
-        @OptIn(DFInternal::class)
-        public inline fun <reified T : Any> empty(meta: Meta = Meta.EMPTY): DataTree<T> =
-            emptyWithType<T>(typeOf<T>(), meta)
-    }
-}
-
-public fun <T : Any> DataTree<T>.listChildren(prefix: Name): List<Name> =
-    getItem(prefix).tree?.items?.keys?.map { prefix + it } ?: emptyList()
-
-/**
- * Get a [DataTreeItem] with given [name] or null if the item does not exist
- */
-public tailrec fun <T : Any> DataTree<T>.getItem(name: Name): DataTreeItem<T>? = when (name.length) {
-    0 -> DataTreeItem.Node(this)
-    1 -> items[name.firstOrNull()]
-    else -> items[name.firstOrNull()!!].tree?.getItem(name.cutFirst())
-}
-
-public val <T : Any> DataTreeItem<T>?.tree: DataTree<T>? get() = (this as? DataTreeItem.Node<T>)?.tree
-public val <T : Any> DataTreeItem<T>?.data: Data<T>? get() = (this as? DataTreeItem.Leaf<T>)?.data
-
-/**
- * A [Sequence] of all children including nodes
- */
-public fun <T : Any> DataTree<T>.traverseItems(): Sequence<Pair<Name, DataTreeItem<T>>> = sequence {
-    items.forEach { (head, item) ->
-        yield(head.asName() to item)
-        if (item is DataTreeItem.Node) {
-            val subSequence = item.tree.traverseItems()
-                .map { (name, data) -> (head.asName() + name) to data }
-            yieldAll(subSequence)
-        }
-    }
-}
-
-/**
- * Get a branch of this [DataTree] with a given [branchName].
- * The difference from similar method for [DataSet] is that internal logic is more simple and the return value is a [DataTree]
- */
-@OptIn(DFInternal::class)
-public fun <T : Any> DataTree<T>.branch(branchName: Name): DataTree<T> =
-    getItem(branchName)?.tree ?: DataTree.emptyWithType(dataType)
-
-public fun <T : Any> DataTree<T>.branch(branchName: String): DataTree<T> = branch(branchName.parseAsName())

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/DataTreeBuilder.kt

@@ -1,127 +0,0 @@
-package space.kscience.dataforge.data
-
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.flow.MutableSharedFlow
-import kotlinx.coroutines.launch
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFInternal
-import space.kscience.dataforge.misc.ThreadSafe
-import space.kscience.dataforge.names.*
-import kotlin.collections.set
-import kotlin.coroutines.CoroutineContext
-import kotlin.coroutines.coroutineContext
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
-
-public interface DataSourceBuilder<T : Any> : DataSetBuilder<T>, DataSource<T> {
-    override val updates: MutableSharedFlow<Name>
-}
-
-/**
- * A mutable [DataTree] that propagates updates
- */
-public class DataTreeBuilder<T : Any>(
-    override val dataType: KType,
-    coroutineContext: CoroutineContext,
-) : DataTree<T>, DataSourceBuilder<T> {
-
-    override val coroutineContext: CoroutineContext =
-        coroutineContext + Job(coroutineContext[Job]) + GoalExecutionRestriction()
-
-    private val treeItems = HashMap<NameToken, DataTreeItem<T>>()
-
-    override val items: Map<NameToken, DataTreeItem<T>>
-        get() = treeItems.filter { !it.key.body.startsWith("@") }
-
-    override val updates: MutableSharedFlow<Name> = MutableSharedFlow<Name>()
-
-    @ThreadSafe
-    private fun remove(token: NameToken) {
-        if (treeItems.remove(token) != null) {
-            launch {
-                updates.emit(token.asName())
-            }
-        }
-    }
-
-    override fun remove(name: Name) {
-        if (name.isEmpty()) error("Can't remove the root node")
-        (getItem(name.cutLast()).tree as? DataTreeBuilder)?.remove(name.lastOrNull()!!)
-    }
-
-    @ThreadSafe
-    private fun set(token: NameToken, data: Data<T>) {
-        treeItems[token] = DataTreeItem.Leaf(data)
-    }
-
-    @ThreadSafe
-    private fun set(token: NameToken, node: DataTree<T>) {
-        treeItems[token] = DataTreeItem.Node(node)
-    }
-
-    private fun getOrCreateNode(token: NameToken): DataTreeBuilder<T> =
-        (treeItems[token] as? DataTreeItem.Node<T>)?.tree as? DataTreeBuilder<T>
-            ?: DataTreeBuilder<T>(dataType, coroutineContext).also { set(token, it) }
-
-    private fun getOrCreateNode(name: Name): DataTreeBuilder<T> = when (name.length) {
-        0 -> this
-        1 -> getOrCreateNode(name.firstOrNull()!!)
-        else -> getOrCreateNode(name.firstOrNull()!!).getOrCreateNode(name.cutFirst())
-    }
-
-    override fun data(name: Name, data: Data<T>?) {
-        if (data == null) {
-            remove(name)
-        } else {
-            when (name.length) {
-                0 -> error("Can't add data with empty name")
-                1 -> set(name.firstOrNull()!!, data)
-                2 -> getOrCreateNode(name.cutLast()).set(name.lastOrNull()!!, data)
-            }
-        }
-        launch {
-            updates.emit(name)
-        }
-    }
-
-    override fun meta(name: Name, meta: Meta) {
-        val item = getItem(name)
-        if (item is DataTreeItem.Leaf) error("TODO: Can't change meta of existing leaf item.")
-        data(name + DataTree.META_ITEM_NAME_TOKEN, Data.empty(meta))
-    }
-}
-
-/**
- * Create a dynamic [DataSource]. Initial data is placed synchronously.
- */
-@DFInternal
-@Suppress("FunctionName")
-public fun <T : Any> DataSource(
-    type: KType,
-    parent: CoroutineScope,
-    block: DataSourceBuilder<T>.() -> Unit,
-): DataTreeBuilder<T> = DataTreeBuilder<T>(type, parent.coroutineContext).apply(block)
-
-@Suppress("OPT_IN_USAGE", "FunctionName")
-public inline fun <reified T : Any> DataSource(
-    parent: CoroutineScope,
-    crossinline block: DataSourceBuilder<T>.() -> Unit,
-): DataTreeBuilder<T> = DataSource(typeOf<T>(), parent) { block() }
-
-@Suppress("FunctionName")
-public suspend inline fun <reified T : Any> DataSource(
-    crossinline block: DataSourceBuilder<T>.() -> Unit = {},
-): DataTreeBuilder<T> = DataTreeBuilder<T>(typeOf<T>(), coroutineContext).apply { block() }
-
-public inline fun <reified T : Any> DataSourceBuilder<T>.emit(
-    name: Name,
-    parent: CoroutineScope,
-    noinline block: DataSourceBuilder<T>.() -> Unit,
-): Unit = node(name, DataSource(parent, block))
-
-public inline fun <reified T : Any> DataSourceBuilder<T>.emit(
-    name: String,
-    parent: CoroutineScope,
-    noinline block: DataSourceBuilder<T>.() -> Unit,
-): Unit = node(Name.parse(name), DataSource(parent, block))

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/Goal.kt

@@ -9,7 +9,7 @@ import kotlin.coroutines.EmptyCoroutineContext
  * Lazy computation result with its dependencies to allowing to stat computing dependencies ahead of time
  */
 public interface Goal<out T> {
-    public val dependencies: Collection<Goal<*>>
+    public val dependencies: Iterable<Goal<*>>
 
     /**
      * Returns current running coroutine if the goal is started. Null if the computation is not started.
@@ -54,7 +54,7 @@ public open class StaticGoal<T>(public val value: T) : Goal<T> {
  */
 public open class LazyGoal<T>(
     private val coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    override val dependencies: Collection<Goal<*>> = emptyList(),
+    override val dependencies: Iterable<Goal<*>> = emptyList(),
     public val block: suspend () -> T,
 ) : Goal<T> {
 
@@ -82,8 +82,8 @@ public open class LazyGoal<T>(
         }
 
         log?.emit { "Starting dependencies computation for ${this@LazyGoal}" }
-        val startedDependencies = this.dependencies.map { goal ->
-            goal.run { async(coroutineScope) }
+        val startedDependencies = dependencies.map { goal ->
+            goal.async(coroutineScope)
         }
         return deferred ?: coroutineScope.async(
             coroutineContext

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/GroupRule.kt

@@ -15,13 +15,12 @@
  */
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.launch
 import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.string
-import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.misc.UnsafeKType
 
 public interface GroupRule {
-    public fun <T : Any> gather(set: DataSet<T>): Map<String, DataSet<T>>
+    public fun <T> gather(set: DataTree<T>): Map<String, DataTree<T>>
 
     public companion object {
         /**
@@ -32,42 +31,20 @@ public interface GroupRule {
          * @param defaultTagValue
          * @return
          */
-        @OptIn(DFInternal::class)
+        @OptIn(UnsafeKType::class)
         public fun byMetaValue(
             key: String,
             defaultTagValue: String,
         ): GroupRule = object : GroupRule {
 
-            override fun <T : Any> gather(
-                set: DataSet<T>,
-            ): Map<String, DataSet<T>> {
-                val map = HashMap<String, DataSet<T>>()
+            override fun <T> gather(
+                set: DataTree<T>,
+            ): Map<String, DataTree<T>> {
+                val map = HashMap<String, MutableDataTree<T>>()
 
-                if (set is DataSource) {
-                    set.forEach { data ->
-                        val tagValue: String = data.meta[key]?.string ?: defaultTagValue
-                        (map.getOrPut(tagValue) { DataTreeBuilder(set.dataType, set.coroutineContext) } as DataTreeBuilder<T>)
-                            .data(data.name, data.data)
-
-                        set.launch {
-                            set.updates.collect { name ->
-                                val dataUpdate = set[name]
-
-                                val updateTagValue = dataUpdate?.meta?.get(key)?.string ?: defaultTagValue
-                                map.getOrPut(updateTagValue) {
-                                    DataSource(set.dataType, this) {
-                                        data(name, dataUpdate)
-                                    }
-                                }
-                            }
-                        }
-                    }
-                } else {
-                    set.forEach { data ->
-                        val tagValue: String = data.meta[key]?.string ?: defaultTagValue
-                        (map.getOrPut(tagValue) { StaticDataTree(set.dataType) } as StaticDataTree<T>)
-                            .data(data.name, data.data)
-                    }
+                set.forEach { data ->
+                    val tagValue: String = data.meta[key]?.string ?: defaultTagValue
+                    map.getOrPut(tagValue) { MutableDataTree(set.dataType) }.put(data.name, data.data)
                 }
 
 

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/MetaMaskData.kt

@@ -0,0 +1,23 @@
+package space.kscience.dataforge.data
+
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.MutableMeta
+import space.kscience.dataforge.meta.copy
+
+
+private class MetaMaskData<T>(val origin: Data<T>, override val meta: Meta) : Data<T> by origin
+
+/**
+ * A data with overriden meta. It reflects original data computed state.
+ */
+public fun <T> Data<T>.withMeta(newMeta: Meta): Data<T> = if (this is MetaMaskData) {
+    MetaMaskData(origin, newMeta)
+} else {
+    MetaMaskData(this, newMeta)
+}
+
+/**
+ * Create a new [Data] with the same computation, but different meta. The meta is created by applying [block] to
+ * the existing data meta.
+ */
+public inline fun <T> Data<T>.withMeta(block: MutableMeta.() -> Unit): Data<T> = withMeta(meta.copy(block))

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/NamedData.kt

@@ -3,16 +3,36 @@ package space.kscience.dataforge.data
 import space.kscience.dataforge.meta.isEmpty
 import space.kscience.dataforge.misc.Named
 import space.kscience.dataforge.names.Name
+import kotlin.reflect.KType
 
-public interface NamedData<out T : Any> : Named, Data<T> {
+/**
+ * An interface implementing a data update event.
+ *
+ * If [data] is null, then corresponding element should be removed.
+ */
+public interface DataUpdate<out T> : Named {
+    public val type: KType
     override val name: Name
-    public val data: Data<T>
+    public val data: Data<T>?
+}
+
+public fun <T> DataUpdate(type: KType, name: Name, data: Data<T>?): DataUpdate<T> = object : DataUpdate<T> {
+    override val type: KType = type
+    override val name: Name = name
+    override val data: Data<T>? = data
+}
+
+/**
+ * A data coupled to a name.
+ */
+public interface NamedData<out T> : DataUpdate<T>, Data<T> {
+    override val data: Data<T>
 }
 
 public operator fun NamedData<*>.component1(): Name = name
-public operator fun <T: Any> NamedData<T>.component2(): Data<T> = data
+public operator fun <T> NamedData<T>.component2(): Data<T> = data
 
-private class NamedDataImpl<out T : Any>(
+private class NamedDataImpl<T>(
     override val name: Name,
     override val data: Data<T>,
 ) : Data<T> by data, NamedData<T> {
@@ -28,8 +48,10 @@ private class NamedDataImpl<out T : Any>(
     }
 }
 
-public fun <T : Any> Data<T>.named(name: Name): NamedData<T> = if (this is NamedData) {
+public fun <T> Data<T>.named(name: Name): NamedData<T> = if (this is NamedData) {
     NamedDataImpl(name, this.data)
 } else {
     NamedDataImpl(name, this)
-}
+}
+
+public fun <T> NamedData(name: Name, data: Data<T>): NamedData<T> = data.named(name)

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/StaticDataTree.kt

@@ -1,82 +0,0 @@
-package space.kscience.dataforge.data
-
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.*
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
-
-@PublishedApi
-internal class StaticDataTree<T : Any>(
-    override val dataType: KType,
-) : DataSetBuilder<T>, DataTree<T> {
-
-    private val _items: MutableMap<NameToken, DataTreeItem<T>> = HashMap()
-
-    override val items: Map<NameToken, DataTreeItem<T>>
-        get() = _items.filter { !it.key.body.startsWith("@") }
-
-    override fun remove(name: Name) {
-        when (name.length) {
-            0 -> error("Can't remove root tree node")
-            1 -> _items.remove(name.firstOrNull()!!)
-            else -> (_items[name.firstOrNull()!!].tree as? StaticDataTree<T>)?.remove(name.cutFirst())
-        }
-    }
-
-    private fun getOrCreateNode(name: Name): StaticDataTree<T> = when (name.length) {
-        0 -> this
-        1 -> {
-            val itemName = name.firstOrNull()!!
-            (_items[itemName].tree as? StaticDataTree<T>) ?: StaticDataTree<T>(dataType).also {
-                _items[itemName] = DataTreeItem.Node(it)
-            }
-        }
-        else -> getOrCreateNode(name.cutLast()).getOrCreateNode(name.lastOrNull()!!.asName())
-    }
-
-    private fun set(name: Name, item: DataTreeItem<T>?) {
-        if (name.isEmpty()) error("Can't set top level tree node")
-        if (item == null) {
-            remove(name)
-        } else {
-            getOrCreateNode(name.cutLast())._items[name.lastOrNull()!!] = item
-        }
-    }
-
-    override fun data(name: Name, data: Data<T>?) {
-        set(name, data?.let { DataTreeItem.Leaf(it) })
-    }
-
-    override fun node(name: Name, dataSet: DataSet<T>) {
-        if (dataSet is StaticDataTree) {
-            set(name, DataTreeItem.Node(dataSet))
-        } else {
-            dataSet.forEach {
-                data(name + it.name, it.data)
-            }
-        }
-    }
-
-    override fun meta(name: Name, meta: Meta) {
-        val item = getItem(name)
-        if (item is DataTreeItem.Leaf) TODO("Can't change meta of existing leaf item.")
-        data(name + DataTree.META_ITEM_NAME_TOKEN, Data.empty(meta))
-    }
-}
-
-@Suppress("FunctionName")
-public inline fun <T : Any> DataTree(
-    dataType: KType,
-    block: DataSetBuilder<T>.() -> Unit,
-): DataTree<T> = StaticDataTree<T>(dataType).apply { block() }
-
-@Suppress("FunctionName")
-public inline fun <reified T : Any> DataTree(
-    noinline block: DataSetBuilder<T>.() -> Unit,
-): DataTree<T> = DataTree(typeOf<T>(), block)
-
-@OptIn(DFExperimental::class)
-public fun <T : Any> DataSet<T>.seal(): DataTree<T> = DataTree(dataType) {
-    populateFrom(this@seal)
-}

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/dataBuilders.kt

@@ -0,0 +1,134 @@
+package space.kscience.dataforge.data
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.MutableMeta
+import space.kscience.dataforge.names.*
+
+
+public fun <T> DataSink<T>.put(value: NamedData<T>) {
+    put(value.name, value.data)
+}
+
+public inline fun <T> DataSink<T>.putAll(
+    prefix: Name,
+    block: DataSink<T>.() -> Unit,
+) {
+    if (prefix.isEmpty()) {
+        apply(block)
+    } else {
+        val proxyDataSink = object :DataSink<T>{
+            override fun put(name: Name, data: Data<T>?) {
+                this@putAll.put(prefix + name, data)
+            }
+
+            override suspend fun update(name: Name, data: Data<T>?) {
+                this@putAll.update(prefix + name, data)
+            }
+
+        }
+
+        proxyDataSink.apply(block)
+    }
+}
+
+
+public inline fun <T> DataSink<T>.putAll(
+    prefix: String,
+    block: DataSink<T>.() -> Unit,
+): Unit = putAll(prefix.asName(), block)
+
+
+public fun <T> DataSink<T>.put(name: String, value: Data<T>) {
+    put(Name.parse(name), value)
+}
+
+public fun <T> DataSink<T>.putAll(name: Name, tree: DataTree<T>) {
+    putAll(name) { putAll(tree.asSequence()) }
+}
+
+
+public fun <T> DataSink<T>.putAll(name: String, tree: DataTree<T>) {
+    putAll(Name.parse(name)) { putAll(tree.asSequence()) }
+}
+
+/**
+ * Produce lazy [Data] and emit it into the [MutableDataTree]
+ */
+public inline fun <reified T> DataSink<T>.putValue(
+    name: String,
+    meta: Meta = Meta.EMPTY,
+    noinline producer: suspend () -> T,
+) {
+    val data = Data(meta, block = producer)
+    put(name, data)
+}
+
+public inline fun <reified T> DataSink<T>.putValue(
+    name: Name,
+    meta: Meta = Meta.EMPTY,
+    noinline producer: suspend () -> T,
+) {
+    val data = Data(meta, block = producer)
+    put(name, data)
+}
+
+/**
+ * Emit static data with the fixed value
+ */
+public inline fun <reified T> DataSink<T>.putValue(
+    name: Name,
+    value: T,
+    meta: Meta = Meta.EMPTY,
+): Unit = put(name, Data.wrapValue(value, meta))
+
+public inline fun <reified T> DataSink<T>.putValue(
+    name: String,
+    value: T,
+    meta: Meta = Meta.EMPTY,
+): Unit = put(name, Data.wrapValue(value, meta))
+
+public inline fun <reified T> DataSink<T>.putValue(
+    name: String,
+    value: T,
+    metaBuilder: MutableMeta.() -> Unit,
+): Unit = put(Name.parse(name), Data.wrapValue(value, Meta(metaBuilder)))
+
+public suspend inline fun <reified T> DataSink<T>.updateValue(
+    name: Name,
+    value: T,
+    meta: Meta = Meta.EMPTY,
+): Unit = update(name, Data.wrapValue(value, meta))
+
+public suspend inline fun <reified T> DataSink<T>.updateValue(
+    name: String,
+    value: T,
+    meta: Meta = Meta.EMPTY,
+): Unit = update(name.parseAsName(), Data.wrapValue(value, meta))
+
+public fun <T> DataSink<T>.putAll(sequence: Sequence<NamedData<T>>) {
+    sequence.forEach {
+        put(it.name, it.data)
+    }
+}
+
+public fun <T> DataSink<T>.putAll(tree: DataTree<T>) {
+    putAll(tree.asSequence())
+}
+
+/**
+ * Copy given data set and mirror its changes to this [DataSink] in [this@setAndObserve]. Returns an update [Job]
+ */
+public fun <T : Any> DataSink<T>.putAllAndWatch(
+    scope: CoroutineScope,
+    branchName: Name = Name.EMPTY,
+    source: DataTree<T>,
+): Job {
+    putAll(branchName, source)
+    return source.updates.onEach {
+        update(branchName + it.name, it.data)
+    }.launchIn(scope)
+}

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/dataFilter.kt

@@ -1,105 +0,0 @@
-package space.kscience.dataforge.data
-
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.filter
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.mapNotNull
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.*
-import kotlin.coroutines.CoroutineContext
-import kotlin.coroutines.EmptyCoroutineContext
-import kotlin.reflect.KType
-
-
-/**
- * A stateless filtered [DataSet]
- */
-public fun <T : Any> DataSet<T>.filter(
-    predicate: (Name, Meta) -> Boolean,
-): DataSource<T> = object : DataSource<T> {
-
-    override val dataType: KType get() = this@filter.dataType
-
-    override val coroutineContext: CoroutineContext
-        get() = (this@filter as? DataSource)?.coroutineContext ?: EmptyCoroutineContext
-
-
-    override val meta: Meta get() = this@filter.meta
-
-    override fun iterator(): Iterator<NamedData<T>> = iterator {
-        for (d in this@filter) {
-            if (predicate(d.name, d.meta)) {
-                yield(d)
-            }
-        }
-    }
-
-    override fun get(name: Name): Data<T>? = this@filter.get(name)?.takeIf {
-        predicate(name, it.meta)
-    }
-
-    override val updates: Flow<Name> = this@filter.updates.filter flowFilter@{ name ->
-        val theData = this@filter[name] ?: return@flowFilter false
-        predicate(name, theData.meta)
-    }
-}
-
-/**
- * Generate a wrapper data set with a given name prefix appended to all names
- */
-public fun <T : Any> DataSet<T>.withNamePrefix(prefix: Name): DataSet<T> = if (prefix.isEmpty()) {
-    this
-} else object : DataSource<T> {
-
-    override val dataType: KType get() = this@withNamePrefix.dataType
-
-    override val coroutineContext: CoroutineContext
-        get() = (this@withNamePrefix as? DataSource)?.coroutineContext ?: EmptyCoroutineContext
-
-    override val meta: Meta get() = this@withNamePrefix.meta
-
-
-    override fun iterator(): Iterator<NamedData<T>> = iterator {
-        for (d in this@withNamePrefix) {
-            yield(d.data.named(prefix + d.name))
-        }
-    }
-
-    override fun get(name: Name): Data<T>? =
-        name.removeFirstOrNull(name)?.let { this@withNamePrefix.get(it) }
-
-    override val updates: Flow<Name> get() = this@withNamePrefix.updates.map { prefix + it }
-}
-
-/**
- * Get a subset of data starting with a given [branchName]
- */
-public fun <T : Any> DataSet<T>.branch(branchName: Name): DataSet<T> = if (branchName.isEmpty()) {
-    this
-} else object : DataSource<T> {
-    override val dataType: KType get() = this@branch.dataType
-
-    override val coroutineContext: CoroutineContext
-        get() = (this@branch as? DataSource)?.coroutineContext ?: EmptyCoroutineContext
-
-    override val meta: Meta get() = this@branch.meta
-
-    override fun iterator(): Iterator<NamedData<T>> = iterator {
-        for (d in this@branch) {
-            d.name.removeFirstOrNull(branchName)?.let { name ->
-                yield(d.data.named(name))
-            }
-        }
-    }
-
-    override fun get(name: Name): Data<T>? = this@branch.get(branchName + name)
-
-    override val updates: Flow<Name> get() = this@branch.updates.mapNotNull { it.removeFirstOrNull(branchName) }
-}
-
-public fun <T : Any> DataSet<T>.branch(branchName: String): DataSet<T> = this@branch.branch(branchName.parseAsName())
-
-@DFExperimental
-public suspend fun <T : Any> DataSet<T>.rootData(): Data<T>? = get(Name.EMPTY)
-

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/dataTransform.kt

@@ -1,24 +1,40 @@
 package space.kscience.dataforge.data
 
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MutableMeta
-import space.kscience.dataforge.meta.seal
-import space.kscience.dataforge.meta.toMutableMeta
-import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.meta.*
+import space.kscience.dataforge.misc.UnsafeKType
 import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.NameToken
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.EmptyCoroutineContext
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
-public data class ValueWithMeta<T>(val meta: Meta, val value: T)
+public data class ValueWithMeta<T>(val value: T, val meta: Meta)
 
-public suspend fun <T : Any> Data<T>.awaitWithMeta(): ValueWithMeta<T> = ValueWithMeta(meta, await())
+public suspend fun <T> Data<T>.awaitWithMeta(): ValueWithMeta<T> = ValueWithMeta(await(), meta)
 
-public data class NamedValueWithMeta<T>(val name: Name, val meta: Meta, val value: T)
+public data class NamedValueWithMeta<T>(val name: Name, val value: T, val meta: Meta)
+
+public suspend fun <T> NamedData<T>.awaitWithMeta(): NamedValueWithMeta<T> =
+    NamedValueWithMeta(name, await(), meta)
+
+/**
+ * Lazily transform this data to another data. By convention [block] should not use external data (be pure).
+ * @param type explicit type of the resulting [Data]
+ * @param coroutineContext additional [CoroutineContext] elements used for data computation.
+ * @param meta for the resulting data. By default equals input data.
+ * @param block the transformation itself
+ */
+@UnsafeKType
+public fun <T, R> Data<T>.transform(
+    type: KType,
+    meta: Meta = this.meta,
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
+    block: suspend (T) -> R,
+): Data<R> = Data(type, meta, coroutineContext, listOf(this)) {
+    block(await())
+}
 
-public suspend fun <T : Any> NamedData<T>.awaitWithMeta(): NamedValueWithMeta<T> =
-    NamedValueWithMeta(name, meta, await())
 
 
 /**
@@ -27,9 +43,9 @@ public suspend fun <T : Any> NamedData<T>.awaitWithMeta(): NamedValueWithMeta<T>
  * @param meta for the resulting data. By default equals input data.
  * @param block the transformation itself
  */
-public inline fun <T : Any, reified R : Any> Data<T>.map(
-    coroutineContext: CoroutineContext = EmptyCoroutineContext,
+public inline fun <T, reified R> Data<T>.transform(
     meta: Meta = this.meta,
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
     crossinline block: suspend (T) -> R,
 ): Data<R> = Data(meta, coroutineContext, listOf(this)) {
     block(await())
@@ -38,10 +54,10 @@ public inline fun <T : Any, reified R : Any> Data<T>.map(
 /**
  * Combine this data with the other data using [block]. See [Data::map] for other details
  */
-public inline fun <T1 : Any, T2 : Any, reified R : Any> Data<T1>.combine(
+public inline fun <T1, T2, reified R> Data<T1>.combine(
     other: Data<T2>,
-    coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = this.meta,
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
     crossinline block: suspend (left: T1, right: T2) -> R,
 ): Data<R> = Data(meta, coroutineContext, listOf(this, other)) {
     block(await(), other.await())
@@ -50,26 +66,31 @@ public inline fun <T1 : Any, T2 : Any, reified R : Any> Data<T1>.combine(
 
 //data collection operations
 
-/**
- * Lazily reduce a collection of [Data] to a single data.
- */
-public inline fun <T : Any, reified R : Any> Collection<Data<T>>.reduceToData(
-    coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
-    crossinline block: suspend (List<ValueWithMeta<T>>) -> R,
-): Data<R> = Data(
-    meta,
-    coroutineContext,
-    this
-) {
-    block(map { it.awaitWithMeta() })
+@PublishedApi
+internal fun Iterable<Data<*>>.joinMeta(): Meta = Meta {
+    var counter = 0
+    forEach { data ->
+        val inputIndex = (data as? NamedData)?.name?.toString() ?: (counter++).toString()
+        val token = NameToken("data", inputIndex)
+        set(token, data.meta)
+    }
 }
 
-@DFInternal
-public fun <K, T : Any, R : Any> Map<K, Data<T>>.reduceToData(
+
+
+@PublishedApi
+internal fun Map<*, Data<*>>.joinMeta(): Meta = Meta {
+    forEach { (key, data) ->
+        val token = NameToken("data", key.toString())
+        set(token, data.meta)
+    }
+}
+
+@UnsafeKType
+public fun <K, T, R> Map<K, Data<T>>.reduceToData(
     outputType: KType,
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     block: suspend (Map<K, ValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     outputType,
@@ -86,9 +107,9 @@ public fun <K, T : Any, R : Any> Map<K, Data<T>>.reduceToData(
  * @param T type of the input goal
  * @param R type of the result goal
  */
-public inline fun <K, T : Any, reified R : Any> Map<K, Data<T>>.reduceToData(
+public inline fun <K, T, reified R> Map<K, Data<T>>.reduceToData(
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline block: suspend (Map<K, ValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     meta,
@@ -100,11 +121,11 @@ public inline fun <K, T : Any, reified R : Any> Map<K, Data<T>>.reduceToData(
 
 //Iterable operations
 
-@DFInternal
-public inline fun <T : Any, R : Any> Iterable<Data<T>>.reduceToData(
+@UnsafeKType
+public inline fun <T, R> Iterable<Data<T>>.reduceToData(
     outputType: KType,
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline transformation: suspend (Collection<ValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     outputType,
@@ -115,22 +136,22 @@ public inline fun <T : Any, R : Any> Iterable<Data<T>>.reduceToData(
     transformation(map { it.awaitWithMeta() })
 }
 
-@OptIn(DFInternal::class)
-public inline fun <T : Any, reified R : Any> Iterable<Data<T>>.reduceToData(
+@OptIn(UnsafeKType::class)
+public inline fun <T, reified R> Iterable<Data<T>>.reduceToData(
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline transformation: suspend (Collection<ValueWithMeta<T>>) -> R,
-): Data<R> = reduceToData(typeOf<R>(), coroutineContext, meta) {
+): Data<R> = reduceToData(typeOf<R>(), meta, coroutineContext) {
     transformation(it)
 }
 
-public inline fun <T : Any, reified R : Any> Iterable<Data<T>>.foldToData(
+public inline fun <T, reified R> Iterable<Data<T>>.foldToData(
     initial: R,
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline block: suspend (result: R, data: ValueWithMeta<T>) -> R,
 ): Data<R> = reduceToData(
-    coroutineContext, meta
+    meta, coroutineContext
 ) {
     it.fold(initial) { acc, t -> block(acc, t) }
 }
@@ -138,11 +159,11 @@ public inline fun <T : Any, reified R : Any> Iterable<Data<T>>.foldToData(
 /**
  * Transform an [Iterable] of [NamedData] to a single [Data].
  */
-@DFInternal
-public inline fun <T : Any, R : Any> Iterable<NamedData<T>>.reduceNamedToData(
+@UnsafeKType
+public inline fun <T, R> Iterable<NamedData<T>>.reduceNamedToData(
     outputType: KType,
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline transformation: suspend (Collection<NamedValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     outputType,
@@ -153,69 +174,79 @@ public inline fun <T : Any, R : Any> Iterable<NamedData<T>>.reduceNamedToData(
     transformation(map { it.awaitWithMeta() })
 }
 
-@OptIn(DFInternal::class)
-public inline fun <T : Any, reified R : Any> Iterable<NamedData<T>>.reduceNamedToData(
+@OptIn(UnsafeKType::class)
+public inline fun <T, reified R> Iterable<NamedData<T>>.reduceNamedToData(
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline transformation: suspend (Collection<NamedValueWithMeta<T>>) -> R,
-): Data<R> = reduceNamedToData(typeOf<R>(), coroutineContext, meta) {
+): Data<R> = reduceNamedToData(typeOf<R>(), meta, coroutineContext) {
     transformation(it)
 }
 
 /**
  * Fold a [Iterable] of named data into a single [Data]
  */
-public inline fun <T : Any, reified R : Any> Iterable<NamedData<T>>.foldNamedToData(
+public inline fun <T, reified R> Iterable<NamedData<T>>.foldNamedToData(
     initial: R,
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline block: suspend (result: R, data: NamedValueWithMeta<T>) -> R,
 ): Data<R> = reduceNamedToData(
-    coroutineContext, meta
+    meta, coroutineContext
 ) {
     it.fold(initial) { acc, t -> block(acc, t) }
 }
 
 //DataSet operations
 
-@DFInternal
-public suspend fun <T : Any, R : Any> DataSet<T>.map(
+
+@UnsafeKType
+public suspend fun <T, R> DataTree<T>.transform(
     outputType: KType,
-    coroutineContext: CoroutineContext = EmptyCoroutineContext,
     metaTransform: MutableMeta.() -> Unit = {},
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
     block: suspend (NamedValueWithMeta<T>) -> R,
-): DataTree<R> = DataTree<R>(outputType) {
-    forEach {
-        val newMeta = it.meta.toMutableMeta().apply(metaTransform).seal()
-        val d = Data(outputType, newMeta, coroutineContext, listOf(it)) {
-            block(it.awaitWithMeta())
+): DataTree<R> = DataTree<R>(outputType){
+    //quasi-synchronous processing of elements in the tree
+    asSequence().forEach { namedData: NamedData<T> ->
+        val newMeta = namedData.meta.toMutableMeta().apply(metaTransform).seal()
+        val d = Data(outputType, newMeta, coroutineContext, listOf(namedData)) {
+            block(namedData.awaitWithMeta())
         }
-        data(it.name, d)
+        put(namedData.name, d)
     }
 }
 
-@OptIn(DFInternal::class)
-public suspend inline fun <T : Any, reified R : Any> DataSet<T>.map(
-    coroutineContext: CoroutineContext = EmptyCoroutineContext,
+@OptIn(UnsafeKType::class)
+public suspend inline fun <T, reified R> DataTree<T>.transform(
     noinline metaTransform: MutableMeta.() -> Unit = {},
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
     noinline block: suspend (NamedValueWithMeta<T>) -> R,
-): DataTree<R> = map(typeOf<R>(), coroutineContext, metaTransform, block)
+): DataTree<R> = this@transform.transform(typeOf<R>(), metaTransform, coroutineContext, block)
 
-public inline fun <T : Any> DataSet<T>.forEach(block: (NamedData<T>) -> Unit) {
-    for (d in this) {
-        block(d)
+public inline fun <T> DataTree<T>.forEach(block: (NamedData<T>) -> Unit) {
+    asSequence().forEach(block)
+}
+
+// DataSet reduction
+
+@PublishedApi
+internal fun DataTree<*>.joinMeta(): Meta = Meta {
+    asSequence().forEach {
+        val token = NameToken("data", it.name.toString())
+        set(token, it.meta)
     }
 }
 
-public inline fun <T : Any, reified R : Any> DataSet<T>.reduceToData(
+public inline fun <T, reified R> DataTree<T>.reduceToData(
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline transformation: suspend (Iterable<NamedValueWithMeta<T>>) -> R,
-): Data<R> = asIterable().reduceNamedToData(coroutineContext, meta, transformation)
+): Data<R> = asSequence().asIterable().reduceNamedToData(meta, coroutineContext, transformation)
 
-public inline fun <T : Any, reified R : Any> DataSet<T>.foldToData(
+public inline fun <T, reified R> DataTree<T>.foldToData(
     initial: R,
+    meta: Meta = joinMeta(),
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    meta: Meta = Meta.EMPTY,
     crossinline block: suspend (result: R, data: NamedValueWithMeta<T>) -> R,
-): Data<R> = asIterable().foldNamedToData(initial, coroutineContext, meta, block)
+): Data<R> = asSequence().asIterable().foldNamedToData(initial, meta, coroutineContext, block)

dataforge-data/src/commonMain/kotlin/space/kscience/dataforge/data/dataTreeBuilder.kt

@@ -0,0 +1,112 @@
+package space.kscience.dataforge.data
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.mapNotNull
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import space.kscience.dataforge.misc.UnsafeKType
+import space.kscience.dataforge.names.*
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
+
+
+private class FlatDataTree<T>(
+    override val dataType: KType,
+    private val dataSet: Map<Name, Data<T>>,
+    private val sourceUpdates: Flow<DataUpdate<T>>,
+    private val prefix: Name,
+) : DataTree<T> {
+    override val data: Data<T>? get() = dataSet[prefix]
+    override val items: Map<NameToken, FlatDataTree<T>>
+        get() = dataSet.keys
+            .filter { it.startsWith(prefix) && it.length > prefix.length }
+            .map { it.tokens[prefix.length] }
+            .associateWith { FlatDataTree(dataType, dataSet, sourceUpdates, prefix + it) }
+
+    override fun read(name: Name): Data<T>? = dataSet[prefix + name]
+
+    override val updates: Flow<DataUpdate<T>> =
+        sourceUpdates.mapNotNull { update ->
+            update.name.removeFirstOrNull(prefix)?.let { DataUpdate(dataType, it, update.data) }
+        }
+}
+
+/**
+ * A builder for static [DataTree].
+ */
+private class DataTreeBuilder<T>(
+    private val type: KType,
+    initialData: Map<Name, Data<T>> = emptyMap(),
+) : DataSink<T> {
+
+    private val map = HashMap<Name, Data<T>>(initialData)
+
+    private val mutex = Mutex()
+
+    private val updatesFlow = MutableSharedFlow<DataUpdate<T>>()
+
+    override fun put(name: Name, data: Data<T>?) {
+        if (data == null) {
+            map.remove(name)
+        } else {
+            map[name] = data
+        }
+    }
+
+    override suspend fun update(name: Name, data: Data<T>?) {
+        mutex.withLock {
+            if (data == null) {
+                map.remove(name)
+            } else {
+                map.put(name, data)
+            }
+        }
+        updatesFlow.emit(DataUpdate(data?.type ?: type, name, data))
+    }
+
+    public fun build(): DataTree<T> = FlatDataTree(type, map, updatesFlow, Name.EMPTY)
+}
+
+/**
+ * Create a static [DataTree]
+ */
+@UnsafeKType
+public fun <T> DataTree(
+    dataType: KType,
+    generator: DataSink<T>.() -> Unit,
+): DataTree<T> = DataTreeBuilder<T>(dataType).apply(generator).build()
+
+/**
+ * Create and a data tree.
+ */
+@OptIn(UnsafeKType::class)
+public inline fun <reified T> DataTree(
+    noinline generator: DataSink<T>.() -> Unit,
+): DataTree<T> = DataTree(typeOf<T>(), generator)
+
+
+/**
+ * Represent this flat data map as a [DataTree] without copying it
+ */
+@UnsafeKType
+public fun <T> Map<Name, Data<T>>.asTree(type: KType): DataTree<T> =
+    DataTreeBuilder(type, this).build()
+
+/**
+ * Represent this flat data map as a [DataTree] without copying it
+ */
+@OptIn(UnsafeKType::class)
+public inline fun <reified T> Map<Name, Data<T>>.asTree(): DataTree<T> = asTree(typeOf<T>())
+
+
+@UnsafeKType
+public fun <T> Sequence<NamedData<T>>.toTree(type: KType): DataTree<T> =
+    DataTreeBuilder(type, associate { it.name to it.data }).build()
+
+
+/**
+ * Collect a sequence of [NamedData] to a [DataTree]
+ */
+@OptIn(UnsafeKType::class)
+public inline fun <reified T> Sequence<NamedData<T>>.toTree(): DataTree<T> = toTree(typeOf<T>())

dataforge-data/src/commonTest/kotlin/space/kscience/dataforge/data/DataTreeBuilderTest.kt

@@ -0,0 +1,73 @@
+package space.kscience.dataforge.data
+
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.take
+import kotlinx.coroutines.test.runTest
+import space.kscience.dataforge.names.asName
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.time.Duration.Companion.milliseconds
+
+
+internal class DataTreeBuilderTest {
+    @Test
+    fun testTreeBuild() = runTest(timeout = 500.milliseconds) {
+        val node = DataTree<Any> {
+            putAll("primary") {
+                putValue("a", "a")
+                putValue("b", "b")
+            }
+            putValue("c.d", "c.d")
+            putValue("c.f", "c.f")
+        }
+        assertEquals("a", node["primary.a"]?.await())
+        assertEquals("b", node["primary.b"]?.await())
+        assertEquals("c.d", node["c.d"]?.await())
+        assertEquals("c.f", node["c.f"]?.await())
+
+    }
+
+    @Test
+    fun testDataUpdate() = runTest(timeout = 500.milliseconds) {
+        val updateData = DataTree<Any> {
+            putAll("update") {
+                put("a", Data.wrapValue("a"))
+                put("b", Data.wrapValue("b"))
+            }
+        }
+
+        val node = DataTree<Any> {
+            putAll("primary") {
+                putValue("a", "a")
+                putValue("b", "b")
+            }
+            putValue("root", "root")
+            putAll(updateData)
+        }
+
+        assertEquals("a", node["update.a"]?.await())
+        assertEquals("a", node["primary.a"]?.await())
+    }
+
+    @Test
+    fun testDynamicUpdates() = runTest(timeout = 500.milliseconds) {
+        var job: Job? = null
+
+        val subNode = MutableDataTree<Int>()
+
+        val rootNode = MutableDataTree<Int>() {
+            job = putAllAndWatch(this@runTest, "sub".asName(), subNode)
+        }
+
+        repeat(10) {
+            subNode.updateValue("value[$it]", it)
+        }
+
+        rootNode.updates.take(10).collect()
+        assertEquals(9, rootNode["sub.value[9]"]?.await())
+        assertEquals(8, rootNode["sub.value[8]"]?.await())
+
+        job?.cancel()
+    }
+}

dataforge-data/src/jvmMain/kotlin/space/kscience/dataforge/data/actionInContext.kt

@@ -1,2 +0,0 @@
-package space.kscience.dataforge.data
-

dataforge-data/src/jvmMain/kotlin/space/kscience/dataforge/data/dataFilterJvm.kt

@@ -2,11 +2,8 @@ package space.kscience.dataforge.data
 
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.filter
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFExperimental
+import space.kscience.dataforge.misc.DFInternal
 import space.kscience.dataforge.names.Name
-import kotlin.coroutines.CoroutineContext
-import kotlin.coroutines.EmptyCoroutineContext
 import kotlin.reflect.KType
 import kotlin.reflect.full.isSubtypeOf
 import kotlin.reflect.typeOf
@@ -16,7 +13,7 @@ import kotlin.reflect.typeOf
  * Cast the node to given type if the cast is possible or return null
  */
 @Suppress("UNCHECKED_CAST")
-private fun <R : Any> Data<*>.castOrNull(type: KType): Data<R>? =
+private fun <R> Data<*>.castOrNull(type: KType): Data<R>? =
     if (!this.type.isSubtypeOf(type)) {
         null
     } else {
@@ -25,61 +22,51 @@ private fun <R : Any> Data<*>.castOrNull(type: KType): Data<R>? =
         }
     }
 
+@Suppress("UNCHECKED_CAST")
+@DFInternal
+public fun <R> Sequence<DataUpdate<*>>.filterByDataType(type: KType): Sequence<NamedData<R>> =
+    filter { it.type.isSubtypeOf(type) } as Sequence<NamedData<R>>
+
+@Suppress("UNCHECKED_CAST")
+@DFInternal
+public fun <R> Flow<DataUpdate<*>>.filterByDataType(type: KType): Flow<NamedData<R>> =
+    filter { it.type.isSubtypeOf(type) } as Flow<NamedData<R>>
+
 /**
  * Select all data matching given type and filters. Does not modify paths
  *
- * @param predicate addition filtering condition based on item name and meta. By default, accepts all
+ * @param filter additional filtering condition based on item name and meta. By default, accepts all
  */
-@OptIn(DFExperimental::class)
-public fun <R : Any> DataSet<*>.filterByType(
+@Suppress("UNCHECKED_CAST")
+@DFInternal
+public fun <R> DataTree<*>.filterByType(
     type: KType,
-    predicate: (name: Name, meta: Meta) -> Boolean = { _, _ -> true },
-): DataSource<R> = object : DataSource<R> {
-    override val dataType = type
-
-    override val coroutineContext: CoroutineContext
-        get() = (this@filterByType as? DataSource)?.coroutineContext ?: EmptyCoroutineContext
-
-    override val meta: Meta get() = this@filterByType.meta
-
-    private fun checkDatum(name: Name, datum: Data<*>): Boolean = datum.type.isSubtypeOf(type)
-            && predicate(name, datum.meta)
-
-    override fun iterator(): Iterator<NamedData<R>> = iterator {
-        for(d in this@filterByType){
-            if(checkDatum(d.name,d.data)){
-                @Suppress("UNCHECKED_CAST")
-                yield(d as NamedData<R>)
-            }
-        }
-    }
-
-    override fun get(name: Name): Data<R>? = this@filterByType[name]?.let { datum ->
-        if (checkDatum(name, datum)) datum.castOrNull(type) else null
-    }
-
-    override val updates: Flow<Name> = this@filterByType.updates.filter { name ->
-        get(name)?.let { datum ->
-            checkDatum(name, datum)
-        } ?: false
+    branch: Name = Name.EMPTY,
+    filter: DataFilter = DataFilter.EMPTY,
+): DataTree<R> {
+    val filterWithType = DataFilter { name, meta, dataType ->
+        filter.accepts(name, meta, dataType) && dataType.isSubtypeOf(type)
     }
+    return FilteredDataTree(this, filterWithType, branch, type) as DataTree<R>
 }
 
 /**
  * Select a single datum of the appropriate type
  */
-public inline fun <reified R : Any> DataSet<*>.filterByType(
-    noinline predicate: (name: Name, meta: Meta) -> Boolean = { _, _ -> true },
-): DataSet<R> = filterByType(typeOf<R>(), predicate)
+@OptIn(DFInternal::class)
+public inline fun <reified R : Any> DataTree<*>.filterByType(
+    branch: Name = Name.EMPTY,
+    filter: DataFilter = DataFilter.EMPTY,
+): DataTree<R> = filterByType(typeOf<R>(), branch, filter = filter)
 
 /**
  * Select a single datum if it is present and of given [type]
  */
-public fun <R : Any> DataSet<*>.getByType(type: KType, name: Name): NamedData<R>? =
+public fun <R> DataTree<*>.getByType(type: KType, name: Name): NamedData<R>? =
     get(name)?.castOrNull<R>(type)?.named(name)
 
-public inline fun <reified R : Any> DataSet<*>.getByType(name: Name): NamedData<R>? =
+public inline fun <reified R : Any> DataTree<*>.getByType(name: Name): NamedData<R>? =
     this@getByType.getByType(typeOf<R>(), name)
 
-public inline fun <reified R : Any> DataSet<*>.getByType(name: String): NamedData<R>? =
-    this@getByType.getByType(typeOf<R>(), Name.parse(name))
+public inline fun <reified R : Any> DataTree<*>.getByType(name: String): NamedData<R>? =
+    this@getByType.getByType(typeOf<R>(), Name.parse(name))

dataforge-data/src/jvmMain/kotlin/space/kscience/dataforge/data/dataSetBuilderInContext.kt

@@ -1,40 +1,27 @@
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.launch
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.plus
 
 
 /**
  * Append data to node
  */
-context(DataSetBuilder<T>) public infix fun <T : Any> String.put(data: Data<T>): Unit =
-    data(Name.parse(this), data)
+context(DataSink<T>)
+public infix fun <T : Any> String.put(data: Data<T>): Unit =
+    put(Name.parse(this), data)
 
 /**
  * Append node
  */
-context(DataSetBuilder<T>) public infix fun <T : Any> String.put(dataSet: DataSet<T>): Unit =
-    node(Name.parse(this), dataSet)
+context(DataSink<T>)
+public infix fun <T : Any> String.putAll(dataSet: DataTree<T>): Unit =
+    putAll(this, dataSet)
 
 /**
  * Build and append node
  */
-context(DataSetBuilder<T>) public infix fun <T : Any> String.put(
-    block: DataSetBuilder<T>.() -> Unit,
-): Unit = node(Name.parse(this), block)
+context(DataSink<T>)
+public infix fun <T : Any> String.putAll(
+    block: DataSink<T>.() -> Unit,
+): Unit = putAll(Name.parse(this), block)
 
-/**
- * Copy given data set and mirror its changes to this [DataTreeBuilder] in [this@setAndObserve]. Returns an update [Job]
- */
-context(DataSetBuilder<T>) public fun <T : Any> CoroutineScope.setAndWatch(
-    name: Name,
-    dataSet: DataSet<T>,
-): Job = launch {
-    node(name, dataSet)
-    dataSet.updates.collect { nameInBranch ->
-        data(name + nameInBranch, dataSet.get(nameInBranch))
-    }
-}

dataforge-data/src/jvmTest/kotlin/space/kscience/dataforge/data/ActionsTest.kt

@@ -1,26 +1,28 @@
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.take
 import kotlinx.coroutines.test.runTest
-import org.junit.jupiter.api.Test
 import space.kscience.dataforge.actions.Action
 import space.kscience.dataforge.actions.invoke
-import space.kscience.dataforge.actions.map
+import space.kscience.dataforge.actions.mapping
 import space.kscience.dataforge.misc.DFExperimental
+import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.time.Duration.Companion.milliseconds
 
-@OptIn(DFExperimental::class, ExperimentalCoroutinesApi::class)
+@OptIn(DFExperimental::class)
 internal class ActionsTest {
     @Test
-    fun testStaticMapAction() = runTest {
+    fun testStaticMapAction() = runTest(timeout = 500.milliseconds) {
         val data: DataTree<Int> = DataTree {
             repeat(10) {
-                static(it.toString(), it)
+                putValue(it.toString(), it)
             }
         }
 
-        val plusOne = Action.map<Int, Int> {
+        val plusOne = Action.mapping<Int, Int> {
             result { it + 1 }
         }
         val result = plusOne(data)
@@ -28,23 +30,23 @@ internal class ActionsTest {
     }
 
     @Test
-    fun testDynamicMapAction() = runTest {
-        val data: DataSourceBuilder<Int> = DataSource()
+    fun testDynamicMapAction() = runTest(timeout = 500.milliseconds) {
+        val source: MutableDataTree<Int> = MutableDataTree()
 
-        val plusOne = Action.map<Int, Int> {
+        val plusOne = Action.mapping<Int, Int> {
             result { it + 1 }
         }
 
-        val result = plusOne(data)
+        val result = plusOne(source)
+
 
         repeat(10) {
-            data.static(it.toString(), it)
+            source.updateValue(it.toString(), it)
         }
 
-        delay(20)
+        result.updates.take(10).onEach { println(it.name) }.collect()
 
         assertEquals(2, result["1"]?.await())
-        data.close()
     }
 
 }

dataforge-data/src/jvmTest/kotlin/space/kscience/dataforge/data/DataTreeBuilderTest.kt

@@ -1,91 +0,0 @@
-package space.kscience.dataforge.data
-
-import kotlinx.coroutines.*
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.asName
-import kotlin.test.Test
-import kotlin.test.assertEquals
-
-
-internal class DataTreeBuilderTest {
-    @Test
-    fun testTreeBuild() = runBlocking {
-        val node = DataTree<Any> {
-            "primary" put {
-                static("a", "a")
-                static("b", "b")
-            }
-            static("c.d", "c.d")
-            static("c.f", "c.f")
-        }
-        runBlocking {
-            assertEquals("a", node["primary.a"]?.await())
-            assertEquals("b", node["primary.b"]?.await())
-            assertEquals("c.d", node["c.d"]?.await())
-            assertEquals("c.f", node["c.f"]?.await())
-        }
-    }
-
-    @OptIn(DFExperimental::class)
-    @Test
-    fun testDataUpdate() = runBlocking {
-        val updateData: DataTree<Any> = DataTree {
-            "update" put {
-                "a" put Data.static("a")
-                "b" put Data.static("b")
-            }
-        }
-
-        val node = DataTree<Any> {
-            "primary" put {
-                static("a", "a")
-                static("b", "b")
-            }
-            static("root", "root")
-            populateFrom(updateData)
-        }
-
-        runBlocking {
-            assertEquals("a", node["update.a"]?.await())
-            assertEquals("a", node["primary.a"]?.await())
-        }
-    }
-
-    @Test
-    fun testDynamicUpdates() = runBlocking {
-        try {
-            lateinit var updateJob: Job
-            supervisorScope {
-                val subNode = DataSource<Int> {
-                    updateJob = launch {
-                        repeat(10) {
-                            delay(10)
-                            static("value", it)
-                        }
-                        delay(10)
-                    }
-                }
-                launch {
-                    subNode.updatesWithData.collect {
-                        println(it)
-                    }
-                }
-                val rootNode = DataSource<Int> {
-                    setAndWatch("sub".asName(), subNode)
-                }
-
-                launch {
-                    rootNode.updatesWithData.collect {
-                        println(it)
-                    }
-                }
-                updateJob.join()
-                assertEquals(9, rootNode["sub.value"]?.await())
-                cancel()
-            }
-        } catch (t: Throwable) {
-            if (t !is CancellationException) throw t
-        }
-
-    }
-}

dataforge-io/README.md

@@ -6,18 +6,16 @@ IO module
 
 ## Artifact:
 
-The Maven coordinates of this project are `space.kscience:dataforge-io:0.7.0`.
+The Maven coordinates of this project are `space.kscience:dataforge-io:0.8.2`.
 
 **Gradle Kotlin DSL:**
 ```kotlin
 repositories {
     maven("https://repo.kotlin.link")
-    //uncomment to access development builds
-    //maven("https://maven.pkg.jetbrains.space/spc/p/sci/dev")
     mavenCentral()
 }
 
 dependencies {
-    implementation("space.kscience:dataforge-io:0.7.0")
+    implementation("space.kscience:dataforge-io:0.8.2")
 }
 ```

dataforge-io/build.gradle.kts

@@ -4,12 +4,13 @@ plugins {
 
 description = "IO module"
 
-val ioVersion = "0.2.1"
+val ioVersion = "0.3.1"
 
 kscience {
     jvm()
     js()
     native()
+    wasm()
     useSerialization()
     useSerialization(sourceSet = space.kscience.gradle.DependencySourceSet.TEST) {
         cbor()

dataforge-io/dataforge-io-yaml/README.md

@@ -6,18 +6,16 @@ YAML meta IO
 
 ## Artifact:
 
-The Maven coordinates of this project are `space.kscience:dataforge-io-yaml:0.7.0`.
+The Maven coordinates of this project are `space.kscience:dataforge-io-yaml:0.8.2`.
 
 **Gradle Kotlin DSL:**
 ```kotlin
 repositories {
     maven("https://repo.kotlin.link")
-    //uncomment to access development builds
-    //maven("https://maven.pkg.jetbrains.space/spc/p/sci/dev")
     mavenCentral()
 }
 
 dependencies {
-    implementation("space.kscience:dataforge-io-yaml:0.7.0")
+    implementation("space.kscience:dataforge-io-yaml:0.8.2")
 }
 ```

dataforge-io/src/commonMain/kotlin/space/kscience/dataforge/io/Binary.kt

@@ -71,6 +71,11 @@ internal class ByteArrayBinary(
 
     override fun view(offset: Int, binarySize: Int): ByteArrayBinary =
         ByteArrayBinary(array, start + offset, binarySize)
+
+    override fun toString(): String =
+        "ByteArrayBinary(array=$array, start=$start, size=$size)"
+
+
 }
 
 public fun ByteArray.asBinary(): Binary = ByteArrayBinary(this)

dataforge-io/src/commonMain/kotlin/space/kscience/dataforge/io/EnvelopeFormat.kt

@@ -4,20 +4,17 @@ import kotlinx.io.Source
 import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.io.EnvelopeFormatFactory.Companion.ENVELOPE_FORMAT_TYPE
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.DfType
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
-public interface EnvelopeFormat : IOFormat<Envelope> {
-
-    override val type: KType get() = typeOf<Envelope>()
-}
+public interface EnvelopeFormat : IOFormat<Envelope>
 
 public fun EnvelopeFormat.read(input: Source): Envelope = readFrom(input)
 
-@DfId(ENVELOPE_FORMAT_TYPE)
+@DfType(ENVELOPE_FORMAT_TYPE)
 public interface EnvelopeFormatFactory : IOFormatFactory<Envelope>, EnvelopeFormat {
     override val type: KType get() = typeOf<Envelope>()
 

dataforge-io/src/commonMain/kotlin/space/kscience/dataforge/io/EnvelopeParts.kt

@@ -11,6 +11,7 @@ import space.kscience.dataforge.io.PartDescriptor.Companion.PARTS_KEY
 import space.kscience.dataforge.io.PartDescriptor.Companion.SEPARATOR_KEY
 import space.kscience.dataforge.meta.*
 import space.kscience.dataforge.names.asName
+import space.kscience.dataforge.names.getIndexedList
 import space.kscience.dataforge.names.plus
 
 private class PartDescriptor : Scheme() {
@@ -84,7 +85,7 @@ public fun EnvelopeBuilder.envelopes(
 public fun Envelope.parts(): EnvelopeParts {
     if (data == null) return emptyList()
     //TODO add zip folder reader
-    val parts = meta.getIndexed(PARTS_KEY).values.map {
+    val parts = meta.getIndexedList(PARTS_KEY).map {
         PartDescriptor.read(it)
     }
     return if (parts.isEmpty()) {

dataforge-io/src/commonMain/kotlin/space/kscience/dataforge/io/IOFormat.kt

@@ -7,7 +7,7 @@ import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.context.Factory
 import space.kscience.dataforge.io.IOFormatFactory.Companion.IO_FORMAT_TYPE
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.DfType
 import space.kscience.dataforge.misc.Named
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
@@ -17,11 +17,7 @@ import kotlin.reflect.typeOf
 /**
  * Reader of a custom object from input
  */
-public interface IOReader<out T> {
-    /**
-     * The type of object being read
-     */
-    public val type: KType
+public fun interface IOReader<out T> {
 
     public fun readFrom(source: Source): T
 
@@ -32,7 +28,6 @@ public interface IOReader<out T> {
          * no-op reader for binaries.
          */
         public val binary: IOReader<Binary> = object : IOReader<Binary> {
-            override val type: KType = typeOf<Binary>()
 
             override fun readFrom(source: Source): Binary = source.readByteArray().asBinary()
 
@@ -42,8 +37,6 @@ public interface IOReader<out T> {
 }
 
 public inline fun <reified T> IOReader(crossinline read: Source.() -> T): IOReader<T> = object : IOReader<T> {
-    override val type: KType = typeOf<T>()
-
     override fun readFrom(source: Source): T = source.read()
 }
 
@@ -56,24 +49,24 @@ public fun interface IOWriter<in T> {
  */
 public interface IOFormat<T> : IOReader<T>, IOWriter<T>
 
-public fun <T : Any> Source.readWith(format: IOReader<T>): T = format.readFrom(this)
+public fun <T> Source.readWith(format: IOReader<T>): T = format.readFrom(this)
 
 /**
  * Read given binary as an object using given format
  */
-public fun <T : Any> Binary.readWith(format: IOReader<T>): T = read {
-    readWith(format)
+public fun <T> Binary.readWith(format: IOReader<T>): T = read {
+    this.readWith(format)
 }
 
 /**
  * Write an object to the [Sink] with given [format]
  */
-public fun <T : Any> Sink.writeWith(format: IOWriter<T>, obj: T): Unit =
+public fun <T> Sink.writeWith(format: IOWriter<T>, obj: T): Unit =
     format.writeTo(this, obj)
 
 
-@DfId(IO_FORMAT_TYPE)
-public interface IOFormatFactory<T : Any> : Factory<IOFormat<T>>, Named {
+@DfType(IO_FORMAT_TYPE)
+public interface IOFormatFactory<T> : Factory<IOFormat<T>>, Named {
     /**
      * Explicit type for dynamic type checks
      */
@@ -86,7 +79,7 @@ public interface IOFormatFactory<T : Any> : Factory<IOFormat<T>>, Named {
     }
 }
 
-public fun <T : Any> Binary(obj: T, format: IOWriter<T>): Binary = Binary { format.writeTo(this, obj) }
+public fun <T> Binary(obj: T, format: IOWriter<T>): Binary = Binary { format.writeTo(this, obj) }
 
 public object FloatIOFormat : IOFormat<Float>, IOFormatFactory<Float> {
     override fun build(context: Context, meta: Meta): IOFormat<Float> = this

dataforge-io/src/commonMain/kotlin/space/kscience/dataforge/io/IOPlugin.kt

@@ -5,9 +5,8 @@ import space.kscience.dataforge.io.EnvelopeFormatFactory.Companion.ENVELOPE_FORM
 import space.kscience.dataforge.io.IOFormatFactory.Companion.IO_FORMAT_TYPE
 import space.kscience.dataforge.io.MetaFormatFactory.Companion.META_FORMAT_TYPE
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.string
-import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.misc.UnsafeKType
 import space.kscience.dataforge.names.Name
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
@@ -20,12 +19,12 @@ public class IOPlugin(meta: Meta) : AbstractPlugin(meta) {
     }
 
     @Suppress("UNCHECKED_CAST")
-    @DFInternal
-    public fun <T : Any> resolveIOFormat(type: KType, meta: Meta): IOFormat<T>? =
+    @UnsafeKType
+    public fun <T> resolveIOFormat(type: KType, meta: Meta): IOFormat<T>? =
         ioFormatFactories.singleOrNull { it.type == type }?.build(context, meta) as? IOFormat<T>
 
-    @OptIn(DFInternal::class)
-    public inline fun <reified T : Any> resolveIOFormat(meta: Meta = Meta.EMPTY): IOFormat<T>? =
+    @OptIn(UnsafeKType::class)
+    public inline fun <reified T> resolveIOFormat(meta: Meta = Meta.EMPTY): IOFormat<T>? =
         resolveIOFormat(typeOf<T>(), meta)
 
 

dataforge-io/src/commonMain/kotlin/space/kscience/dataforge/io/MetaFormat.kt

@@ -9,7 +9,7 @@ import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.io.MetaFormatFactory.Companion.META_FORMAT_TYPE
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.descriptors.MetaDescriptor
-import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.DfType
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
 import space.kscience.dataforge.names.plus
@@ -21,8 +21,6 @@ import kotlin.reflect.typeOf
  */
 public interface MetaFormat : IOFormat<Meta> {
 
-    override val type: KType get() = typeOf<Meta>()
-
     override fun writeTo(sink: Sink, obj: Meta) {
         writeMeta(sink, obj, null)
     }
@@ -38,7 +36,7 @@ public interface MetaFormat : IOFormat<Meta> {
     public fun readMeta(source: Source, descriptor: MetaDescriptor? = null): Meta
 }
 
-@DfId(META_FORMAT_TYPE)
+@DfType(META_FORMAT_TYPE)
 public interface MetaFormatFactory : IOFormatFactory<Meta>, MetaFormat {
     public val shortName: String
 

dataforge-io/src/commonMain/kotlin/space/kscience/dataforge/io/ioMisc.kt

@@ -5,7 +5,6 @@ import kotlinx.io.bytestring.ByteString
 import kotlinx.io.bytestring.decodeToString
 import kotlinx.io.bytestring.encodeToByteString
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFExperimental
 import kotlin.math.min
 
 /**
@@ -52,7 +51,6 @@ public fun IOPlugin.peekBinaryEnvelopeFormat(binary: Binary): EnvelopeFormat? {
 /**
  * A zero-copy read from
  */
-@DFExperimental
 public fun IOPlugin.readEnvelope(
     binary: Binary,
     readNonEnvelopes: Boolean = false,
@@ -62,7 +60,6 @@ public fun IOPlugin.readEnvelope(
     Envelope(Meta.EMPTY, binary)
 } else error("Can't infer format for $binary")
 
-@DFExperimental
 public fun IOPlugin.readEnvelope(
     string: String,
     readNonEnvelopes: Boolean = false,

dataforge-io/src/jvmMain/kotlin/space/kscience/dataforge/io/fileIO.kt

@@ -77,14 +77,12 @@ public fun Path.rewrite(block: Sink.() -> Unit): Unit {
     stream.asSink().buffered().use(block)
 }
 
-@DFExperimental
 public fun EnvelopeFormat.readFile(path: Path): Envelope = readFrom(path.asBinary())
 
 /**
  * Resolve IOFormat based on type
  */
 @Suppress("UNCHECKED_CAST")
-@DFExperimental
 public inline fun <reified T : Any> IOPlugin.resolveIOFormat(): IOFormat<T>? =
     ioFormatFactories.find { it.type.isSupertypeOf(typeOf<T>()) } as IOFormat<T>?
 
@@ -192,7 +190,6 @@ public fun IOPlugin.peekFileEnvelopeFormat(path: Path): EnvelopeFormat? {
  *
  * Return null otherwise.
  */
-@DFExperimental
 public fun IOPlugin.readEnvelopeFile(
     path: Path,
     readNonEnvelopes: Boolean = false,

dataforge-meta/README.md

@@ -6,18 +6,16 @@ Meta definition and basic operations on meta
 
 ## Artifact:
 
-The Maven coordinates of this project are `space.kscience:dataforge-meta:0.7.0`.
+The Maven coordinates of this project are `space.kscience:dataforge-meta:0.8.2`.
 
 **Gradle Kotlin DSL:**
 ```kotlin
 repositories {
     maven("https://repo.kotlin.link")
-    //uncomment to access development builds
-    //maven("https://maven.pkg.jetbrains.space/spc/p/sci/dev")
     mavenCentral()
 }
 
 dependencies {
-    implementation("space.kscience:dataforge-meta:0.7.0")
+    implementation("space.kscience:dataforge-meta:0.8.2")
 }
 ```

dataforge-meta/api/dataforge-meta.api

@@ -1,3 +1,15 @@
+public final class space/kscience/dataforge/meta/ByteArrayValue : java/lang/Iterable, kotlin/jvm/internal/markers/KMappedMarker, space/kscience/dataforge/meta/Value {
+	public fun <init> ([B)V
+	public fun equals (Ljava/lang/Object;)Z
+	public fun getList ()Ljava/util/List;
+	public fun getType ()Lspace/kscience/dataforge/meta/ValueType;
+	public synthetic fun getValue ()Ljava/lang/Object;
+	public fun getValue ()[B
+	public fun hashCode ()I
+	public fun iterator ()Ljava/util/Iterator;
+	public fun toString ()Ljava/lang/String;
+}
+
 public abstract interface class space/kscience/dataforge/meta/Configurable {
 	public abstract fun getMeta ()Lspace/kscience/dataforge/meta/MutableMeta;
 }
@@ -30,7 +42,20 @@ public final class space/kscience/dataforge/meta/EnumValue : space/kscience/data
 }
 
 public final class space/kscience/dataforge/meta/ExoticValuesKt {
+	public static final fun asValue ([B)Lspace/kscience/dataforge/meta/Value;
 	public static final fun asValue ([D)Lspace/kscience/dataforge/meta/Value;
+	public static final fun byteArray (Lspace/kscience/dataforge/meta/MetaProvider;[BLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
+	public static final fun byteArray (Lspace/kscience/dataforge/meta/MutableMetaProvider;[BLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun byteArray$default (Lspace/kscience/dataforge/meta/MetaProvider;[BLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
+	public static synthetic fun byteArray$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;[BLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun doubleArray (Lspace/kscience/dataforge/meta/MetaProvider;[DLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
+	public static final fun doubleArray (Lspace/kscience/dataforge/meta/MutableMetaProvider;[DLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun doubleArray$default (Lspace/kscience/dataforge/meta/MetaProvider;[DLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
+	public static synthetic fun doubleArray$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;[DLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun getByteArray (Lspace/kscience/dataforge/meta/Meta;)[B
+	public static final fun getByteArray (Lspace/kscience/dataforge/meta/Value;)[B
+	public static final fun getDoubleArray (Lspace/kscience/dataforge/meta/Meta;)[D
+	public static final fun getDoubleArray (Lspace/kscience/dataforge/meta/Value;)[D
 	public static final fun lazyParseValue (Ljava/lang/String;)Lspace/kscience/dataforge/meta/LazyParsedValue;
 }
 
@@ -56,6 +81,20 @@ public final class space/kscience/dataforge/meta/JsonMetaKt {
 	public static final fun toValue (Lkotlinx/serialization/json/JsonPrimitive;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)Lspace/kscience/dataforge/meta/Value;
 }
 
+public final class space/kscience/dataforge/meta/KeepTransformationRule : space/kscience/dataforge/meta/TransformationRule {
+	public fun <init> (Lkotlin/jvm/functions/Function1;)V
+	public final fun component1 ()Lkotlin/jvm/functions/Function1;
+	public final fun copy (Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/KeepTransformationRule;
+	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/KeepTransformationRule;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/KeepTransformationRule;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getSelector ()Lkotlin/jvm/functions/Function1;
+	public fun hashCode ()I
+	public fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
+	public fun selectItems (Lspace/kscience/dataforge/meta/Meta;)Lkotlin/sequences/Sequence;
+	public fun toString ()Ljava/lang/String;
+	public fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
+}
+
 public final class space/kscience/dataforge/meta/Laminate : space/kscience/dataforge/meta/TypedMeta {
 	public static final field Companion Lspace/kscience/dataforge/meta/Laminate$Companion;
 	public fun equals (Ljava/lang/Object;)Z
@@ -159,49 +198,82 @@ public final class space/kscience/dataforge/meta/MetaBuilder : space/kscience/da
 public abstract interface annotation class space/kscience/dataforge/meta/MetaBuilderMarker : java/lang/annotation/Annotation {
 }
 
+public abstract interface class space/kscience/dataforge/meta/MetaConverter : space/kscience/dataforge/meta/MetaSpec {
+	public static final field Companion Lspace/kscience/dataforge/meta/MetaConverter$Companion;
+	public abstract fun convert (Ljava/lang/Object;)Lspace/kscience/dataforge/meta/Meta;
+	public fun getDescriptor ()Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
+	public fun read (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+	public abstract fun readOrNull (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+}
+
+public final class space/kscience/dataforge/meta/MetaConverter$Companion {
+	public final fun getBoolean ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getDouble ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getFloat ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getInt ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getLong ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getMeta ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getNumber ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getString ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun getValue ()Lspace/kscience/dataforge/meta/MetaConverter;
+	public final fun valueList (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/MetaConverter;
+	public static synthetic fun valueList$default (Lspace/kscience/dataforge/meta/MetaConverter$Companion;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaConverter;
+}
+
+public final class space/kscience/dataforge/meta/MetaConverterKt {
+	public static final fun convertNullable (Lspace/kscience/dataforge/meta/MetaConverter;Ljava/lang/Object;)Lspace/kscience/dataforge/meta/Meta;
+}
+
+public abstract interface class space/kscience/dataforge/meta/MetaDelegate : kotlin/properties/ReadOnlyProperty, space/kscience/dataforge/meta/descriptors/Described {
+}
+
 public final class space/kscience/dataforge/meta/MetaDelegateKt {
-	public static final fun boolean (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun boolean (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun boolean (Lspace/kscience/dataforge/meta/MetaProvider;ZLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MetaProvider;ZLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun double (Lspace/kscience/dataforge/meta/MetaProvider;DLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun double (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MetaProvider;DLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun float (Lspace/kscience/dataforge/meta/MetaProvider;FLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun float (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MetaProvider;FLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun int (Lspace/kscience/dataforge/meta/MetaProvider;ILspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun int (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MetaProvider;ILspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun long (Lspace/kscience/dataforge/meta/MetaProvider;JLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun long (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MetaProvider;JLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun node (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun node (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/transformations/MetaConverter;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/transformations/MetaConverter;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun number (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun number (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun number (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun string (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun string (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun string (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun value (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadOnlyProperty;
-	public static final fun value (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
+	public static final fun boolean (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun boolean (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun boolean (Lspace/kscience/dataforge/meta/MetaProvider;ZLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MetaProvider;ZLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun double (Lspace/kscience/dataforge/meta/MetaProvider;DLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun double (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MetaProvider;DLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun float (Lspace/kscience/dataforge/meta/MetaProvider;FLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun float (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MetaProvider;FLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun int (Lspace/kscience/dataforge/meta/MetaProvider;ILspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun int (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MetaProvider;ILspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun listOfSpec (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MetaSpec;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun listOfSpec$default (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MetaSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun long (Lspace/kscience/dataforge/meta/MetaProvider;JLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun long (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MetaProvider;JLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun node (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/MetaSpec;)Lkotlin/properties/ReadOnlyProperty;
+	public static final fun node (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/MetaSpec;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
+	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun number (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun number (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun number (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun spec (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/meta/MetaSpec;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun spec$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/meta/MetaSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun string (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun string (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun string (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun value (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static final fun value (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
+	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MetaDelegate;
 }
 
 public final class space/kscience/dataforge/meta/MetaKt {
@@ -252,6 +324,47 @@ public final class space/kscience/dataforge/meta/MetaSerializer : kotlinx/serial
 	public fun serialize (Lkotlinx/serialization/encoding/Encoder;Lspace/kscience/dataforge/meta/Meta;)V
 }
 
+public abstract interface class space/kscience/dataforge/meta/MetaSpec : space/kscience/dataforge/meta/descriptors/Described {
+	public fun read (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+	public abstract fun readOrNull (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+}
+
+public final class space/kscience/dataforge/meta/MetaSpecKt {
+	public static final fun readNullable (Lspace/kscience/dataforge/meta/MetaSpec;Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+	public static final fun readValue (Lspace/kscience/dataforge/meta/MetaSpec;Lspace/kscience/dataforge/meta/Value;)Ljava/lang/Object;
+}
+
+public final class space/kscience/dataforge/meta/MetaTransformation {
+	public static final field Companion Lspace/kscience/dataforge/meta/MetaTransformation$Companion;
+	public static final fun apply-impl (Ljava/util/Collection;Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/Meta;
+	public static final fun bind-impl (Ljava/util/Collection;Lspace/kscience/dataforge/meta/ObservableMeta;Lspace/kscience/dataforge/meta/MutableMeta;)V
+	public static final synthetic fun box-impl (Ljava/util/Collection;)Lspace/kscience/dataforge/meta/MetaTransformation;
+	public static fun constructor-impl (Ljava/util/Collection;)Ljava/util/Collection;
+	public fun equals (Ljava/lang/Object;)Z
+	public static fun equals-impl (Ljava/util/Collection;Ljava/lang/Object;)Z
+	public static final fun equals-impl0 (Ljava/util/Collection;Ljava/util/Collection;)Z
+	public static final fun generate-impl (Ljava/util/Collection;Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/Meta;
+	public fun hashCode ()I
+	public static fun hashCode-impl (Ljava/util/Collection;)I
+	public fun toString ()Ljava/lang/String;
+	public static fun toString-impl (Ljava/util/Collection;)Ljava/lang/String;
+	public final synthetic fun unbox-impl ()Ljava/util/Collection;
+}
+
+public final class space/kscience/dataforge/meta/MetaTransformation$Companion {
+	public final fun make--mWxz5M (Lkotlin/jvm/functions/Function1;)Ljava/util/Collection;
+}
+
+public final class space/kscience/dataforge/meta/MetaTransformationBuilder {
+	public fun <init> ()V
+	public final fun build-m6Fha10 ()Ljava/util/Collection;
+	public final fun keep (Ljava/lang/String;)V
+	public final fun keep (Lkotlin/jvm/functions/Function1;)V
+	public final fun keep (Lspace/kscience/dataforge/names/Name;)V
+	public final fun move (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)V
+	public static synthetic fun move$default (Lspace/kscience/dataforge/meta/MetaTransformationBuilder;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
+}
+
 public abstract interface class space/kscience/dataforge/meta/MutableMeta : space/kscience/dataforge/meta/Meta, space/kscience/dataforge/meta/MutableMetaProvider {
 	public static final field Companion Lspace/kscience/dataforge/meta/MutableMeta$Companion;
 	public synthetic fun get (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/Meta;
@@ -267,6 +380,7 @@ public abstract interface class space/kscience/dataforge/meta/MutableMeta : spac
 	public fun put (Ljava/lang/String;Lspace/kscience/dataforge/meta/MetaRepr;)V
 	public fun put (Ljava/lang/String;Lspace/kscience/dataforge/meta/Value;)V
 	public fun put (Ljava/lang/String;Z)V
+	public fun put (Ljava/lang/String;[B)V
 	public fun put (Ljava/lang/String;[D)V
 	public fun put (Lspace/kscience/dataforge/names/Name;Ljava/lang/Enum;)V
 	public fun put (Lspace/kscience/dataforge/names/Name;Ljava/lang/Number;)V
@@ -286,64 +400,70 @@ public final class space/kscience/dataforge/meta/MutableMeta$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
+public abstract interface class space/kscience/dataforge/meta/MutableMetaDelegate : kotlin/properties/ReadWriteProperty, space/kscience/dataforge/meta/descriptors/Described {
+}
+
 public final class space/kscience/dataforge/meta/MutableMetaDelegateKt {
-	public static final fun boolean (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun boolean (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun boolean (Lspace/kscience/dataforge/meta/MutableMetaProvider;ZLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;ZLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun double (Lspace/kscience/dataforge/meta/MutableMetaProvider;DLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun double (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;DLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun doubleArray (Lspace/kscience/dataforge/meta/MutableMetaProvider;[DLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun doubleArray$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;[DLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun float (Lspace/kscience/dataforge/meta/MutableMetaProvider;FLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun float (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;FLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun int (Lspace/kscience/dataforge/meta/MutableMetaProvider;ILspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun int (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;ILspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun listValue (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun listValue$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun long (Lspace/kscience/dataforge/meta/MutableMetaProvider;JLspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun long (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;JLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun node (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun node (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/transformations/MetaConverter;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/transformations/MetaConverter;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun number (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun number (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun number (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun numberList (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun numberList$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun string (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun string (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun string (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun stringList (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun stringList (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/String;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun stringList$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun stringList$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/String;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun value (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun value (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun boolean (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun boolean (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun boolean (Lspace/kscience/dataforge/meta/MutableMetaProvider;ZLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun boolean$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;ZLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun convertable (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/meta/MetaConverter;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun convertable$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/meta/MetaConverter;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun double (Lspace/kscience/dataforge/meta/MutableMetaProvider;DLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun double (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;DLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun double$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun float (Lspace/kscience/dataforge/meta/MutableMetaProvider;FLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun float (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;FLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun float$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun int (Lspace/kscience/dataforge/meta/MutableMetaProvider;ILspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun int (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;ILspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun int$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun listOfConvertable (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/MetaConverter;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun listOfConvertable$default (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/MetaConverter;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun listValue (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun listValue$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun long (Lspace/kscience/dataforge/meta/MutableMetaProvider;JLspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun long (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;JLspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun long$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun node (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/MetaConverter;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun node (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/MetaConverter;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun number (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun number (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun number (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun number$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun numberList (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun numberList$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/Number;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun string (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun string (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun string (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun string$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun stringList (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun stringList (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/String;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun stringList$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun stringList$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;[Ljava/lang/String;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun value (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static final fun value (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
+	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/MutableMetaDelegate;
 }
 
 public final class space/kscience/dataforge/meta/MutableMetaKt {
 	public static final fun ObservableMutableMeta ()Lspace/kscience/dataforge/meta/ObservableMutableMeta;
 	public static final fun ObservableMutableMeta (Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/ObservableMutableMeta;
+	public static final fun ObservableMutableMeta (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/ObservableMutableMeta;
 	public static synthetic fun ObservableMutableMeta$default (Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/ObservableMutableMeta;
 	public static final fun append (Lspace/kscience/dataforge/meta/MutableMeta;Ljava/lang/String;Lspace/kscience/dataforge/meta/Meta;)V
 	public static final fun append (Lspace/kscience/dataforge/meta/MutableMeta;Ljava/lang/String;Lspace/kscience/dataforge/meta/Value;)V
@@ -357,6 +477,7 @@ public final class space/kscience/dataforge/meta/MutableMetaKt {
 	public static final fun getOrCreate (Lspace/kscience/dataforge/meta/MutableTypedMeta;Ljava/lang/String;)Lspace/kscience/dataforge/meta/MutableTypedMeta;
 	public static final fun remove (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/String;)V
 	public static final fun remove (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;)V
+	public static final fun reset (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/Meta;)V
 	public static final fun set (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/String;Ljava/lang/Iterable;)V
 	public static final fun set (Lspace/kscience/dataforge/meta/MutableMetaProvider;Ljava/lang/String;Lspace/kscience/dataforge/meta/Meta;)V
 	public static final fun set (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Ljava/lang/Iterable;)V
@@ -365,7 +486,7 @@ public final class space/kscience/dataforge/meta/MutableMetaKt {
 	public static final fun set (Lspace/kscience/dataforge/meta/MutableValueProvider;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Value;)V
 	public static final fun setIndexed (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Ljava/lang/Iterable;Lkotlin/jvm/functions/Function2;)V
 	public static synthetic fun setIndexed$default (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/names/Name;Ljava/lang/Iterable;Lkotlin/jvm/functions/Function2;ILjava/lang/Object;)V
-	public static final fun toMutableMeta (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/ObservableMutableMeta;
+	public static final fun toMutableMeta (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/MutableMeta;
 	public static final fun update (Lspace/kscience/dataforge/meta/MutableMetaProvider;Lspace/kscience/dataforge/meta/Meta;)V
 	public static final fun withDefault (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/MetaProvider;)Lspace/kscience/dataforge/meta/MutableMeta;
 }
@@ -419,11 +540,6 @@ public abstract interface class space/kscience/dataforge/meta/ObservableMeta : s
 	public abstract fun removeListener (Ljava/lang/Object;)V
 }
 
-public final class space/kscience/dataforge/meta/ObservableMetaKt {
-	public static final fun useProperty (Lspace/kscience/dataforge/meta/Scheme;Lkotlin/reflect/KProperty1;Ljava/lang/Object;Lkotlin/jvm/functions/Function2;)V
-	public static synthetic fun useProperty$default (Lspace/kscience/dataforge/meta/Scheme;Lkotlin/reflect/KProperty1;Ljava/lang/Object;Lkotlin/jvm/functions/Function2;ILjava/lang/Object;)V
-}
-
 public final class space/kscience/dataforge/meta/ObservableMetaWrapperKt {
 	public static final fun asObservable (Lspace/kscience/dataforge/meta/MutableMeta;)Lspace/kscience/dataforge/meta/ObservableMutableMeta;
 }
@@ -437,14 +553,25 @@ public abstract interface class space/kscience/dataforge/meta/ObservableMutableM
 	public abstract fun getOrCreate (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/ObservableMutableMeta;
 }
 
-public abstract interface class space/kscience/dataforge/meta/ReadOnlySpecification : space/kscience/dataforge/meta/descriptors/Described {
-	public abstract fun empty ()Ljava/lang/Object;
-	public fun invoke (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
-	public abstract fun read (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+public final class space/kscience/dataforge/meta/RegexItemTransformationRule : space/kscience/dataforge/meta/TransformationRule {
+	public fun <init> (Lkotlin/text/Regex;Lkotlin/jvm/functions/Function4;)V
+	public final fun component1 ()Lkotlin/text/Regex;
+	public final fun component2 ()Lkotlin/jvm/functions/Function4;
+	public final fun copy (Lkotlin/text/Regex;Lkotlin/jvm/functions/Function4;)Lspace/kscience/dataforge/meta/RegexItemTransformationRule;
+	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/RegexItemTransformationRule;Lkotlin/text/Regex;Lkotlin/jvm/functions/Function4;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/RegexItemTransformationRule;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getFrom ()Lkotlin/text/Regex;
+	public final fun getTransform ()Lkotlin/jvm/functions/Function4;
+	public fun hashCode ()I
+	public fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
+	public fun toString ()Ljava/lang/String;
+	public fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
 }
 
 public class space/kscience/dataforge/meta/Scheme : space/kscience/dataforge/meta/Configurable, space/kscience/dataforge/meta/MetaRepr, space/kscience/dataforge/meta/MutableMetaProvider, space/kscience/dataforge/meta/descriptors/Described {
 	public fun <init> ()V
+	public fun <init> (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)V
+	public synthetic fun <init> (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public synthetic fun get (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/Meta;
 	public fun get (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/MutableMeta;
 	public final fun getDescriptor ()Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
@@ -454,6 +581,7 @@ public class space/kscience/dataforge/meta/Scheme : space/kscience/dataforge/met
 	public fun setValue (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Value;)V
 	public fun toMeta ()Lspace/kscience/dataforge/meta/Laminate;
 	public synthetic fun toMeta ()Lspace/kscience/dataforge/meta/Meta;
+	public fun toString ()Ljava/lang/String;
 	public fun validate (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
 }
 
@@ -461,20 +589,34 @@ public final class space/kscience/dataforge/meta/SchemeKt {
 	public static final fun copy (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/Scheme;
 	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/Scheme;
 	public static final fun invoke (Lspace/kscience/dataforge/meta/Scheme;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/Scheme;
-	public static final fun retarget (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/MutableMeta;)Lspace/kscience/dataforge/meta/Scheme;
+	public static final fun listOfScheme (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun listOfScheme (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun listOfScheme$default (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun listOfScheme$default (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun scheme (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun scheme (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun scheme$default (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun scheme$default (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun schemeOrNull (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun schemeOrNull (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun schemeOrNull$default (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static synthetic fun schemeOrNull$default (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/SchemeSpec;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
+	public static final fun updateWith (Lspace/kscience/dataforge/meta/Configurable;Lspace/kscience/dataforge/meta/SchemeSpec;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/Scheme;
+	public static final fun updateWith (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/SchemeSpec;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/Scheme;
+	public static final fun useProperty (Lspace/kscience/dataforge/meta/Scheme;Lkotlin/reflect/KProperty1;Ljava/lang/Object;Lkotlin/jvm/functions/Function2;)V
+	public static synthetic fun useProperty$default (Lspace/kscience/dataforge/meta/Scheme;Lkotlin/reflect/KProperty1;Ljava/lang/Object;Lkotlin/jvm/functions/Function2;ILjava/lang/Object;)V
 }
 
-public class space/kscience/dataforge/meta/SchemeSpec : space/kscience/dataforge/meta/Specification {
+public class space/kscience/dataforge/meta/SchemeSpec : space/kscience/dataforge/meta/MetaConverter {
 	public fun <init> (Lkotlin/jvm/functions/Function0;)V
-	public synthetic fun empty ()Ljava/lang/Object;
-	public fun empty ()Lspace/kscience/dataforge/meta/Scheme;
+	public synthetic fun convert (Ljava/lang/Object;)Lspace/kscience/dataforge/meta/Meta;
+	public fun convert (Lspace/kscience/dataforge/meta/Scheme;)Lspace/kscience/dataforge/meta/Meta;
+	public final fun empty ()Lspace/kscience/dataforge/meta/Scheme;
 	public fun getDescriptor ()Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
-	public synthetic fun invoke (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public final fun invoke (Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/Scheme;
-	public synthetic fun read (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
-	public fun read (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/Scheme;
-	public synthetic fun write (Lspace/kscience/dataforge/meta/MutableMeta;)Ljava/lang/Object;
-	public fun write (Lspace/kscience/dataforge/meta/MutableMeta;)Lspace/kscience/dataforge/meta/Scheme;
+	public synthetic fun readOrNull (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+	public fun readOrNull (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/Scheme;
+	public final fun write (Lspace/kscience/dataforge/meta/MutableMeta;)Lspace/kscience/dataforge/meta/Scheme;
 }
 
 public final class space/kscience/dataforge/meta/SealedMeta : space/kscience/dataforge/meta/TypedMeta {
@@ -515,21 +657,20 @@ public final class space/kscience/dataforge/meta/SealedMetaKt {
 	public static final fun seal (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/SealedMeta;
 }
 
-public abstract interface class space/kscience/dataforge/meta/Specification : space/kscience/dataforge/meta/ReadOnlySpecification {
-	public abstract fun write (Lspace/kscience/dataforge/meta/MutableMeta;)Ljava/lang/Object;
-}
-
-public final class space/kscience/dataforge/meta/SpecificationKt {
-	public static final fun spec (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun spec (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun spec$default (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun spec$default (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun specOrNull (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun specOrNull (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun specOrNull$default (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static synthetic fun specOrNull$default (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/names/Name;ILjava/lang/Object;)Lkotlin/properties/ReadWriteProperty;
-	public static final fun updateWith (Lspace/kscience/dataforge/meta/Configurable;Lspace/kscience/dataforge/meta/Specification;Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
-	public static final fun updateWith (Lspace/kscience/dataforge/meta/MutableMeta;Lspace/kscience/dataforge/meta/Specification;Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
+public final class space/kscience/dataforge/meta/SingleItemTransformationRule : space/kscience/dataforge/meta/TransformationRule {
+	public fun <init> (Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function3;)V
+	public final fun component1 ()Lspace/kscience/dataforge/names/Name;
+	public final fun component2 ()Lkotlin/jvm/functions/Function3;
+	public final fun copy (Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function3;)Lspace/kscience/dataforge/meta/SingleItemTransformationRule;
+	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/SingleItemTransformationRule;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function3;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/SingleItemTransformationRule;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getFrom ()Lspace/kscience/dataforge/names/Name;
+	public final fun getTransform ()Lkotlin/jvm/functions/Function3;
+	public fun hashCode ()I
+	public fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
+	public fun selectItems (Lspace/kscience/dataforge/meta/Meta;)Lkotlin/sequences/Sequence;
+	public fun toString ()Ljava/lang/String;
+	public fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
 }
 
 public final class space/kscience/dataforge/meta/StringValue : space/kscience/dataforge/meta/Value {
@@ -550,6 +691,12 @@ public final class space/kscience/dataforge/meta/StringValue : space/kscience/da
 	public final synthetic fun unbox-impl ()Ljava/lang/String;
 }
 
+public abstract interface class space/kscience/dataforge/meta/TransformationRule {
+	public abstract fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
+	public fun selectItems (Lspace/kscience/dataforge/meta/Meta;)Lkotlin/sequences/Sequence;
+	public abstract fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
+}
+
 public final class space/kscience/dataforge/meta/True : space/kscience/dataforge/meta/Value {
 	public static final field INSTANCE Lspace/kscience/dataforge/meta/True;
 	public fun equals (Ljava/lang/Object;)Z
@@ -587,7 +734,6 @@ public final class space/kscience/dataforge/meta/Value$Companion {
 public final class space/kscience/dataforge/meta/ValueExtensionsKt {
 	public static final fun getBoolean (Lspace/kscience/dataforge/meta/Value;)Z
 	public static final fun getDouble (Lspace/kscience/dataforge/meta/Value;)D
-	public static final fun getDoubleArray (Lspace/kscience/dataforge/meta/Value;)[D
 	public static final fun getFloat (Lspace/kscience/dataforge/meta/Value;)F
 	public static final fun getInt (Lspace/kscience/dataforge/meta/Value;)I
 	public static final fun getLong (Lspace/kscience/dataforge/meta/Value;)J
@@ -606,7 +752,6 @@ public final class space/kscience/dataforge/meta/ValueKt {
 	public static final fun asValue (Ljava/lang/Number;)Lspace/kscience/dataforge/meta/Value;
 	public static final fun asValue (Ljava/lang/String;)Lspace/kscience/dataforge/meta/Value;
 	public static final fun asValue (Z)Lspace/kscience/dataforge/meta/Value;
-	public static final fun asValue ([B)Lspace/kscience/dataforge/meta/Value;
 	public static final fun asValue ([F)Lspace/kscience/dataforge/meta/Value;
 	public static final fun asValue ([I)Lspace/kscience/dataforge/meta/Value;
 	public static final fun asValue ([J)Lspace/kscience/dataforge/meta/Value;
@@ -692,6 +837,7 @@ public final class space/kscience/dataforge/meta/descriptors/MetaDescriptor {
 	public final fun getDescription ()Ljava/lang/String;
 	public final fun getIndexKey ()Ljava/lang/String;
 	public final fun getMultiple ()Z
+	public final fun getNodes ()Ljava/util/Map;
 	public final fun getValueRestriction ()Lspace/kscience/dataforge/meta/descriptors/ValueRestriction;
 	public final fun getValueTypes ()Ljava/util/List;
 	public fun hashCode ()I
@@ -720,25 +866,22 @@ public final class space/kscience/dataforge/meta/descriptors/MetaDescriptorBuild
 	public final fun attributes (Lkotlin/jvm/functions/Function1;)V
 	public final fun build ()Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
 	public final fun default (Ljava/lang/Object;)V
+	public final fun from (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)V
 	public final fun getAllowedValues ()Ljava/util/List;
 	public final fun getAttributes ()Lspace/kscience/dataforge/meta/MutableMeta;
 	public final fun getChildren ()Ljava/util/Map;
 	public final fun getDefault ()Lspace/kscience/dataforge/meta/Value;
+	public final fun getDescription ()Ljava/lang/String;
 	public final fun getIndexKey ()Ljava/lang/String;
-	public final fun getInfo ()Ljava/lang/String;
 	public final fun getMultiple ()Z
 	public final fun getValueRestriction ()Lspace/kscience/dataforge/meta/descriptors/ValueRestriction;
 	public final fun getValueTypes ()Ljava/util/List;
-	public final fun item (Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
-	public static synthetic fun item$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
-	public final fun node (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
-	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
 	public final fun setAllowedValues (Ljava/util/List;)V
 	public final fun setAttributes (Lspace/kscience/dataforge/meta/MutableMeta;)V
 	public final fun setChildren (Ljava/util/Map;)V
 	public final fun setDefault (Lspace/kscience/dataforge/meta/Value;)V
+	public final fun setDescription (Ljava/lang/String;)V
 	public final fun setIndexKey (Ljava/lang/String;)V
-	public final fun setInfo (Ljava/lang/String;)V
 	public final fun setMultiple (Z)V
 	public final fun setValueRestriction (Lspace/kscience/dataforge/meta/descriptors/ValueRestriction;)V
 	public final fun setValueTypes (Ljava/util/List;)V
@@ -749,16 +892,16 @@ public final class space/kscience/dataforge/meta/descriptors/MetaDescriptorBuild
 	public static final fun MetaDescriptor (Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
 	public static final fun copy (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
 	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
-	public static final fun item (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
 	public static final fun node (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lkotlin/jvm/functions/Function1;)V
 	public static final fun node (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lspace/kscience/dataforge/meta/descriptors/Described;Lkotlin/jvm/functions/Function1;)V
-	public static final fun node (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
+	public static final fun node (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;)V
+	public static final fun node (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)V
 	public static synthetic fun node$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lspace/kscience/dataforge/meta/descriptors/Described;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 	public static final fun required (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;)V
-	public static final fun value (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
-	public static final fun value (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
-	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
-	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;
+	public static final fun value (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;)V
+	public static final fun value (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;)V
+	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Ljava/lang/String;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
+	public static synthetic fun value$default (Lspace/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/ValueType;[Lspace/kscience/dataforge/meta/ValueType;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 }
 
 public final class space/kscience/dataforge/meta/descriptors/MetaDescriptorKt {
@@ -772,6 +915,7 @@ public final class space/kscience/dataforge/meta/descriptors/MetaDescriptorKt {
 
 public final class space/kscience/dataforge/meta/descriptors/ValueRestriction : java/lang/Enum {
 	public static final field ABSENT Lspace/kscience/dataforge/meta/descriptors/ValueRestriction;
+	public static final field Companion Lspace/kscience/dataforge/meta/descriptors/ValueRestriction$Companion;
 	public static final field NONE Lspace/kscience/dataforge/meta/descriptors/ValueRestriction;
 	public static final field REQUIRED Lspace/kscience/dataforge/meta/descriptors/ValueRestriction;
 	public static fun getEntries ()Lkotlin/enums/EnumEntries;
@@ -779,115 +923,8 @@ public final class space/kscience/dataforge/meta/descriptors/ValueRestriction :
 	public static fun values ()[Lspace/kscience/dataforge/meta/descriptors/ValueRestriction;
 }
 
-public final class space/kscience/dataforge/meta/transformations/KeepTransformationRule : space/kscience/dataforge/meta/transformations/TransformationRule {
-	public fun <init> (Lkotlin/jvm/functions/Function1;)V
-	public final fun component1 ()Lkotlin/jvm/functions/Function1;
-	public final fun copy (Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/transformations/KeepTransformationRule;
-	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/transformations/KeepTransformationRule;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/transformations/KeepTransformationRule;
-	public fun equals (Ljava/lang/Object;)Z
-	public final fun getSelector ()Lkotlin/jvm/functions/Function1;
-	public fun hashCode ()I
-	public fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
-	public fun selectItems (Lspace/kscience/dataforge/meta/Meta;)Lkotlin/sequences/Sequence;
-	public fun toString ()Ljava/lang/String;
-	public fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
-}
-
-public abstract interface class space/kscience/dataforge/meta/transformations/MetaConverter {
-	public static final field Companion Lspace/kscience/dataforge/meta/transformations/MetaConverter$Companion;
-	public fun getDescriptor ()Lspace/kscience/dataforge/meta/descriptors/MetaDescriptor;
-	public abstract fun getType ()Lkotlin/reflect/KType;
-	public fun metaToObject (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
-	public abstract fun metaToObjectOrNull (Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
-	public abstract fun objectToMeta (Ljava/lang/Object;)Lspace/kscience/dataforge/meta/Meta;
-}
-
-public final class space/kscience/dataforge/meta/transformations/MetaConverter$Companion {
-	public final fun getBoolean ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getDouble ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getFloat ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getInt ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getLong ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getMeta ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getNumber ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getString ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun getValue ()Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public final fun valueList (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-	public static synthetic fun valueList$default (Lspace/kscience/dataforge/meta/transformations/MetaConverter$Companion;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/transformations/MetaConverter;
-}
-
-public final class space/kscience/dataforge/meta/transformations/MetaConverterKt {
-	public static final fun nullableMetaToObject (Lspace/kscience/dataforge/meta/transformations/MetaConverter;Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
-	public static final fun nullableObjectToMeta (Lspace/kscience/dataforge/meta/transformations/MetaConverter;Ljava/lang/Object;)Lspace/kscience/dataforge/meta/Meta;
-	public static final fun valueToObject (Lspace/kscience/dataforge/meta/transformations/MetaConverter;Lspace/kscience/dataforge/meta/Value;)Ljava/lang/Object;
-}
-
-public final class space/kscience/dataforge/meta/transformations/MetaTransformation {
-	public static final field Companion Lspace/kscience/dataforge/meta/transformations/MetaTransformation$Companion;
-	public static final fun apply-impl (Ljava/util/Collection;Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/Meta;
-	public static final fun bind-impl (Ljava/util/Collection;Lspace/kscience/dataforge/meta/ObservableMeta;Lspace/kscience/dataforge/meta/MutableMeta;)V
-	public static final synthetic fun box-impl (Ljava/util/Collection;)Lspace/kscience/dataforge/meta/transformations/MetaTransformation;
-	public static fun constructor-impl (Ljava/util/Collection;)Ljava/util/Collection;
-	public fun equals (Ljava/lang/Object;)Z
-	public static fun equals-impl (Ljava/util/Collection;Ljava/lang/Object;)Z
-	public static final fun equals-impl0 (Ljava/util/Collection;Ljava/util/Collection;)Z
-	public static final fun generate-impl (Ljava/util/Collection;Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/Meta;
-	public fun hashCode ()I
-	public static fun hashCode-impl (Ljava/util/Collection;)I
-	public fun toString ()Ljava/lang/String;
-	public static fun toString-impl (Ljava/util/Collection;)Ljava/lang/String;
-	public final synthetic fun unbox-impl ()Ljava/util/Collection;
-}
-
-public final class space/kscience/dataforge/meta/transformations/MetaTransformation$Companion {
-	public final fun make-XNaMui4 (Lkotlin/jvm/functions/Function1;)Ljava/util/Collection;
-}
-
-public final class space/kscience/dataforge/meta/transformations/MetaTransformationBuilder {
-	public fun <init> ()V
-	public final fun build-050menU ()Ljava/util/Collection;
-	public final fun keep (Ljava/lang/String;)V
-	public final fun keep (Lkotlin/jvm/functions/Function1;)V
-	public final fun keep (Lspace/kscience/dataforge/names/Name;)V
-	public final fun move (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)V
-	public static synthetic fun move$default (Lspace/kscience/dataforge/meta/transformations/MetaTransformationBuilder;Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
-}
-
-public final class space/kscience/dataforge/meta/transformations/RegexItemTransformationRule : space/kscience/dataforge/meta/transformations/TransformationRule {
-	public fun <init> (Lkotlin/text/Regex;Lkotlin/jvm/functions/Function4;)V
-	public final fun component1 ()Lkotlin/text/Regex;
-	public final fun component2 ()Lkotlin/jvm/functions/Function4;
-	public final fun copy (Lkotlin/text/Regex;Lkotlin/jvm/functions/Function4;)Lspace/kscience/dataforge/meta/transformations/RegexItemTransformationRule;
-	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/transformations/RegexItemTransformationRule;Lkotlin/text/Regex;Lkotlin/jvm/functions/Function4;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/transformations/RegexItemTransformationRule;
-	public fun equals (Ljava/lang/Object;)Z
-	public final fun getFrom ()Lkotlin/text/Regex;
-	public final fun getTransform ()Lkotlin/jvm/functions/Function4;
-	public fun hashCode ()I
-	public fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
-	public fun toString ()Ljava/lang/String;
-	public fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
-}
-
-public final class space/kscience/dataforge/meta/transformations/SingleItemTransformationRule : space/kscience/dataforge/meta/transformations/TransformationRule {
-	public fun <init> (Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function3;)V
-	public final fun component1 ()Lspace/kscience/dataforge/names/Name;
-	public final fun component2 ()Lkotlin/jvm/functions/Function3;
-	public final fun copy (Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function3;)Lspace/kscience/dataforge/meta/transformations/SingleItemTransformationRule;
-	public static synthetic fun copy$default (Lspace/kscience/dataforge/meta/transformations/SingleItemTransformationRule;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function3;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/transformations/SingleItemTransformationRule;
-	public fun equals (Ljava/lang/Object;)Z
-	public final fun getFrom ()Lspace/kscience/dataforge/names/Name;
-	public final fun getTransform ()Lkotlin/jvm/functions/Function3;
-	public fun hashCode ()I
-	public fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
-	public fun selectItems (Lspace/kscience/dataforge/meta/Meta;)Lkotlin/sequences/Sequence;
-	public fun toString ()Ljava/lang/String;
-	public fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
-}
-
-public abstract interface class space/kscience/dataforge/meta/transformations/TransformationRule {
-	public abstract fun matches (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;)Z
-	public fun selectItems (Lspace/kscience/dataforge/meta/Meta;)Lkotlin/sequences/Sequence;
-	public abstract fun transformItem (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/meta/MutableMeta;)V
+public final class space/kscience/dataforge/meta/descriptors/ValueRestriction$Companion {
+	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
 public final class space/kscience/dataforge/misc/CastJvmKt {
@@ -903,7 +940,7 @@ public abstract interface annotation class space/kscience/dataforge/misc/DFExper
 public abstract interface annotation class space/kscience/dataforge/misc/DFInternal : java/lang/annotation/Annotation {
 }
 
-public abstract interface annotation class space/kscience/dataforge/misc/DfId : java/lang/annotation/Annotation {
+public abstract interface annotation class space/kscience/dataforge/misc/DfType : java/lang/annotation/Annotation {
 	public abstract fun id ()Ljava/lang/String;
 }
 
@@ -920,6 +957,9 @@ public final class space/kscience/dataforge/misc/NamedKt {
 	public static final fun isAnonymous (Lspace/kscience/dataforge/misc/Named;)Z
 }
 
+public abstract interface annotation class space/kscience/dataforge/misc/UnsafeKType : java/lang/annotation/Annotation {
+}
+
 public final class space/kscience/dataforge/names/Name {
 	public static final field Companion Lspace/kscience/dataforge/names/Name$Companion;
 	public static final field NAME_SEPARATOR Ljava/lang/String;
@@ -937,6 +977,16 @@ public final class space/kscience/dataforge/names/Name$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
+public final class space/kscience/dataforge/names/NameIndexComparator : java/util/Comparator {
+	public static final field INSTANCE Lspace/kscience/dataforge/names/NameIndexComparator;
+	public synthetic fun compare (Ljava/lang/Object;Ljava/lang/Object;)I
+	public fun compare (Ljava/lang/String;Ljava/lang/String;)I
+}
+
+public final class space/kscience/dataforge/names/NameIndexComparatorKt {
+	public static final fun getIndexedList (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/names/Name;)Ljava/util/List;
+}
+
 public final class space/kscience/dataforge/names/NameKt {
 	public static final fun appendFirst (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;)Lspace/kscience/dataforge/names/Name;
 	public static final fun appendLeft (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;)Lspace/kscience/dataforge/names/Name;
@@ -944,6 +994,7 @@ public final class space/kscience/dataforge/names/NameKt {
 	public static final fun asName (Lspace/kscience/dataforge/names/NameToken;)Lspace/kscience/dataforge/names/Name;
 	public static final fun cutFirst (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/names/Name;
 	public static final fun cutLast (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/names/Name;
+	public static final fun endsWith (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;)Z
 	public static final fun endsWith (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/Name;)Z
 	public static final fun endsWith (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/NameToken;)Z
 	public static final fun first (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/names/NameToken;
@@ -966,8 +1017,10 @@ public final class space/kscience/dataforge/names/NameKt {
 	public static final fun removeHeadOrNull (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/names/Name;
 	public static final fun replaceLast (Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/names/Name;
 	public static final fun set (Ljava/util/Map;Ljava/lang/String;Ljava/lang/Object;)V
+	public static final fun startsWith (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;)Z
 	public static final fun startsWith (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/Name;)Z
 	public static final fun startsWith (Lspace/kscience/dataforge/names/Name;Lspace/kscience/dataforge/names/NameToken;)Z
+	public static final fun toStringUnescaped (Lspace/kscience/dataforge/names/Name;)Ljava/lang/String;
 	public static final fun withIndex (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;)Lspace/kscience/dataforge/names/Name;
 }
 

dataforge-meta/build.gradle.kts

@@ -6,6 +6,7 @@ kscience {
     jvm()
     js()
     native()
+    wasm()
     useSerialization{
         json()
     }

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/JsonMeta.kt

@@ -31,7 +31,7 @@ private fun Meta.toJsonWithIndex(descriptor: MetaDescriptor?, index: String?): J
     val pairs: MutableList<Pair<String, JsonElement>> = items.entries.groupBy {
         it.key.body
     }.mapTo(ArrayList()) { (body, list) ->
-        val childDescriptor = descriptor?.children?.get(body)
+        val childDescriptor = descriptor?.nodes?.get(body)
         if (list.size == 1) {
             val (token, element) = list.first()
                 //do not add an empty element

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Laminate.kt

@@ -9,6 +9,8 @@ import space.kscience.dataforge.names.NameToken
  */
 public class Laminate internal constructor(public val layers: List<Meta>) : TypedMeta<Laminate> {
 
+    override val self: Laminate get() = this
+
     override val value: Value? = layers.firstNotNullOfOrNull { it.value }
 
     override val items: Map<NameToken, Laminate> by lazy {

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Meta.kt

@@ -2,8 +2,7 @@ package space.kscience.dataforge.meta
 
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.Json
-import space.kscience.dataforge.misc.DfId
-import space.kscience.dataforge.misc.unsafeCast
+import space.kscience.dataforge.misc.DfType
 import space.kscience.dataforge.names.*
 import kotlin.jvm.JvmName
 
@@ -31,7 +30,7 @@ public fun interface MetaProvider : ValueProvider {
  * TODO add documentation
  * Same name siblings are supported via elements with the same [Name] but different indices.
  */
-@DfId(Meta.TYPE)
+@DfType(Meta.TYPE)
 @Serializable(MetaSerializer::class)
 public interface Meta : MetaRepr, MetaProvider {
     public val value: Value?
@@ -151,6 +150,8 @@ public interface TypedMeta<out M : TypedMeta<M>> : Meta {
 
     override val items: Map<NameToken, M>
 
+    public val self: M
+
     override fun get(name: Name): M? {
         tailrec fun M.find(name: Name): M? = if (name.isEmpty()) {
             this
@@ -164,11 +165,6 @@ public interface TypedMeta<out M : TypedMeta<M>> : Meta {
     override fun toMeta(): Meta = this
 }
 
-/**
- * Access self as a recursive type instance
- */
-public inline val <M : TypedMeta<M>> TypedMeta<M>.self: M get() = unsafeCast()
-
 //public typealias Meta = TypedMeta<*>
 
 public operator fun <M : TypedMeta<M>> TypedMeta<M>?.get(token: NameToken): M? = this?.items?.get(token)
@@ -188,10 +184,12 @@ public operator fun <M : TypedMeta<M>> M?.get(key: String): M? = this?.get(key.p
 
 
 /**
- * Get a sequence of [Name]-[Value] pairs using top-down traversal of the tree
+ * Get a sequence of [Name]-[Value] pairs using top-down traversal of the tree.
+ * The sequence includes root value with empty name
  */
 public fun Meta.valueSequence(): Sequence<Pair<Name, Value>> = sequence {
     items.forEach { (key, item) ->
+        value?.let { yield(Name.EMPTY to it) }
         item.value?.let { itemValue ->
             yield(key.asName() to itemValue)
         }
@@ -248,7 +246,7 @@ public inline fun <reified E : Enum<E>> Meta?.enum(): E? = this?.value?.let {
     }
 }
 
-public val Meta.stringList: List<String>? get() = value?.list?.map { it.string }
+public val Meta?.stringList: List<String>? get() = this?.value?.list?.map { it.string }
 
 /**
  * Create a provider that uses given provider for default values if those are not found in this provider

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MetaConverter.kt

@@ -0,0 +1,159 @@
+package space.kscience.dataforge.meta
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.encodeToJsonElement
+import kotlinx.serialization.serializer
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.misc.DFExperimental
+
+
+/**
+ * A converter of generic object to and from [Meta]
+ */
+public interface MetaConverter<T>: MetaReader<T> {
+
+    /**
+     * A descriptor for resulting meta
+     */
+    override val descriptor: MetaDescriptor? get() = null
+
+    /**
+     * Attempt conversion of [source] to an object or return null if conversion failed
+     */
+    override fun readOrNull(source: Meta): T?
+
+    override fun read(source: Meta): T =
+        readOrNull(source) ?: error("Meta $source could not be interpreted by $this")
+
+    public fun convert(obj: T): Meta
+
+    public companion object {
+
+        public val meta: MetaConverter<Meta> = object : MetaConverter<Meta> {
+            override fun readOrNull(source: Meta): Meta = source
+            override fun convert(obj: Meta): Meta = obj
+        }
+
+        public val value: MetaConverter<Value> = object : MetaConverter<Value> {
+            override fun readOrNull(source: Meta): Value? = source.value
+            override fun convert(obj: Value): Meta = Meta(obj)
+        }
+
+        public val string: MetaConverter<String> = object : MetaConverter<String> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.STRING)
+            }
+
+
+            override fun readOrNull(source: Meta): String? = source.string
+            override fun convert(obj: String): Meta = Meta(obj.asValue())
+        }
+
+        public val boolean: MetaConverter<Boolean> = object : MetaConverter<Boolean> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.BOOLEAN)
+            }
+
+            override fun readOrNull(source: Meta): Boolean? = source.boolean
+            override fun convert(obj: Boolean): Meta = Meta(obj.asValue())
+        }
+
+        public val number: MetaConverter<Number> = object : MetaConverter<Number> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.NUMBER)
+            }
+
+            override fun readOrNull(source: Meta): Number? = source.number
+            override fun convert(obj: Number): Meta = Meta(obj.asValue())
+        }
+
+        public val double: MetaConverter<Double> = object : MetaConverter<Double> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.NUMBER)
+            }
+
+            override fun readOrNull(source: Meta): Double? = source.double
+            override fun convert(obj: Double): Meta = Meta(obj.asValue())
+        }
+
+        public val float: MetaConverter<Float> = object : MetaConverter<Float> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.NUMBER)
+            }
+
+            override fun readOrNull(source: Meta): Float? = source.float
+            override fun convert(obj: Float): Meta = Meta(obj.asValue())
+        }
+
+        public val int: MetaConverter<Int> = object : MetaConverter<Int> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.NUMBER)
+            }
+
+            override fun readOrNull(source: Meta): Int? = source.int
+            override fun convert(obj: Int): Meta = Meta(obj.asValue())
+        }
+
+        public val long: MetaConverter<Long> = object : MetaConverter<Long> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.NUMBER)
+            }
+
+            override fun readOrNull(source: Meta): Long? = source.long
+            override fun convert(obj: Long): Meta = Meta(obj.asValue())
+        }
+
+        public inline fun <reified E : Enum<E>> enum(): MetaConverter<E> = object : MetaConverter<E> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.STRING)
+                allowedValues(enumValues<E>())
+            }
+
+            @Suppress("USELESS_CAST")
+            override fun readOrNull(source: Meta): E = source.enum<E>() as? E ?: error("The Item is not a Enum")
+
+            override fun convert(obj: E): Meta = Meta(obj.asValue())
+        }
+
+        public fun <T> valueList(
+            writer: (T) -> Value = { Value.of(it) },
+            reader: (Value) -> T,
+        ): MetaConverter<List<T>> = object : MetaConverter<List<T>> {
+            override val descriptor: MetaDescriptor = MetaDescriptor {
+                valueType(ValueType.LIST)
+            }
+
+            override fun readOrNull(source: Meta): List<T>? = source.value?.list?.map(reader)
+
+            override fun convert(obj: List<T>): Meta = Meta(obj.map(writer).asValue())
+        }
+
+        /**
+         * Automatically generate [MetaConverter] for a class using its serializer and optional [descriptor]
+         */
+        @DFExperimental
+        public inline fun <reified T> serializable(
+            descriptor: MetaDescriptor? = null,
+            jsonEncoder: Json = Json,
+        ): MetaConverter<T> = object : MetaConverter<T> {
+            private val serializer: KSerializer<T> = serializer()
+
+            override fun readOrNull(source: Meta): T? {
+                val json = source.toJson(descriptor)
+                return jsonEncoder.decodeFromJsonElement(serializer, json)
+            }
+
+            override fun convert(obj: T): Meta {
+                val json = jsonEncoder.encodeToJsonElement(obj)
+                return json.toMeta(descriptor)
+            }
+
+        }
+
+    }
+}
+
+public fun <T : Any> MetaConverter<T>.convertNullable(obj: T?): Meta? = obj?.let { convert(it) }
+
+

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MetaDelegate.kt

@@ -1,84 +1,148 @@
 package space.kscience.dataforge.meta
 
-import space.kscience.dataforge.meta.transformations.MetaConverter
+import space.kscience.dataforge.meta.descriptors.Described
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.misc.DFExperimental
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
 import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
 
 /* Meta delegates */
 
-public fun MetaProvider.node(key: Name? = null): ReadOnlyProperty<Any?, Meta?> = ReadOnlyProperty { _, property ->
-    get(key ?: property.name.asName())
+public interface MetaDelegate<T> : ReadOnlyProperty<Any?, T>, Described
+
+
+public fun MetaProvider.node(
+    key: Name? = null,
+    descriptor: MetaDescriptor? = null,
+): MetaDelegate<Meta?> = object : MetaDelegate<Meta?> {
+    override val descriptor: MetaDescriptor? = descriptor
+
+    override fun getValue(thisRef: Any?, property: KProperty<*>): Meta? {
+        return get(key ?: property.name.asName())
+    }
 }
 
+/**
+ * Use [metaReader] to read the Meta node
+ */
+public fun <T> MetaProvider.spec(
+    metaReader: MetaReader<T>,
+    key: Name? = null,
+): MetaDelegate<T?> = object : MetaDelegate<T?> {
+    override val descriptor: MetaDescriptor? get() = metaReader.descriptor
+
+    override fun getValue(thisRef: Any?, property: KProperty<*>): T? {
+        return get(key ?: property.name.asName())?.let { metaReader.read(it) }
+    }
+}
+
+/**
+ * Use object serializer to transform it to Meta and back
+ */
+@DFExperimental
+public inline fun <reified T> MetaProvider.serializable(
+    key: Name? = null,
+    descriptor: MetaDescriptor? = null,
+): MetaDelegate<T?> = spec(MetaConverter.serializable(descriptor), key)
+
+@Deprecated("Use convertable", ReplaceWith("convertable(converter, key)"))
 public fun <T> MetaProvider.node(
     key: Name? = null,
-    converter: MetaConverter<T>
-): ReadOnlyProperty<Any?, T?> = ReadOnlyProperty { _, property ->
-    get(key ?: property.name.asName())?.let { converter.metaToObject(it) }
+    converter: MetaReader<T>,
+): ReadOnlyProperty<Any?, T?> = spec(converter, key)
+
+/**
+ * Use [converter] to convert a list of same name siblings meta to object
+ */
+public fun <T> Meta.listOfSpec(
+    converter: MetaReader<T>,
+    key: Name? = null,
+): MetaDelegate<List<T>> = object : MetaDelegate<List<T>> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): List<T> {
+        val name = key ?: property.name.asName()
+        return getIndexed(name).values.map { converter.read(it) }
+    }
+
+    override val descriptor: MetaDescriptor? = converter.descriptor?.copy(multiple = true)
 }
 
+@DFExperimental
+public inline fun <reified T> Meta.listOfSerializable(
+    key: Name? = null,
+    descriptor: MetaDescriptor? = null,
+): MetaDelegate<List<T>> = listOfSpec(MetaConverter.serializable(descriptor), key)
+
 /**
  * A property delegate that uses custom key
  */
-public fun MetaProvider.value(key: Name? = null): ReadOnlyProperty<Any?, Value?> = ReadOnlyProperty { _, property ->
-    get(key ?: property.name.asName())?.value
+public fun MetaProvider.value(
+    key: Name? = null,
+    descriptor: MetaDescriptor? = null,
+): MetaDelegate<Value?> = object : MetaDelegate<Value?> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): Value? = get(key ?: property.name.asName())?.value
+
+    override val descriptor: MetaDescriptor? = descriptor
 }
 
 public fun <R> MetaProvider.value(
     key: Name? = null,
-    reader: (Value?) -> R
-): ReadOnlyProperty<Any?, R> = ReadOnlyProperty { _, property ->
-    reader(get(key ?: property.name.asName())?.value)
+    descriptor: MetaDescriptor? = null,
+    reader: (Value?) -> R,
+): MetaDelegate<R> = object : MetaDelegate<R> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): R = reader(get(key ?: property.name.asName())?.value)
+
+    override val descriptor: MetaDescriptor? = descriptor
 }
 
 //TODO add caching for sealed nodes
 
 /* Read-only delegates for [Meta] */
 
-public fun MetaProvider.string(key: Name? = null): ReadOnlyProperty<Any?, String?> = value(key) { it?.string }
+public fun MetaProvider.string(key: Name? = null): MetaDelegate<String?> = value(key = key) { it?.string }
 
-public fun MetaProvider.boolean(key: Name? = null): ReadOnlyProperty<Any?, Boolean?> = value(key) { it?.boolean }
+public fun MetaProvider.boolean(key: Name? = null): MetaDelegate<Boolean?> = value(key = key) { it?.boolean }
 
-public fun MetaProvider.number(key: Name? = null): ReadOnlyProperty<Any?, Number?> = value(key) { it?.numberOrNull }
+public fun MetaProvider.number(key: Name? = null): MetaDelegate<Number?> = value(key = key) { it?.numberOrNull }
 
-public fun MetaProvider.double(key: Name? = null): ReadOnlyProperty<Any?, Double?> = value(key) { it?.double }
+public fun MetaProvider.double(key: Name? = null): MetaDelegate<Double?> = value(key = key) { it?.double }
 
-public fun MetaProvider.float(key: Name? = null): ReadOnlyProperty<Any?, Float?> = value(key) { it?.float }
+public fun MetaProvider.float(key: Name? = null): MetaDelegate<Float?> = value(key = key) { it?.float }
 
-public fun MetaProvider.int(key: Name? = null): ReadOnlyProperty<Any?, Int?> = value(key) { it?.int }
+public fun MetaProvider.int(key: Name? = null): MetaDelegate<Int?> = value(key = key) { it?.int }
 
-public fun MetaProvider.long(key: Name? = null): ReadOnlyProperty<Any?, Long?> = value(key) { it?.long }
+public fun MetaProvider.long(key: Name? = null): MetaDelegate<Long?> = value(key = key) { it?.long }
 
-public fun MetaProvider.string(default: String, key: Name? = null): ReadOnlyProperty<Any?, String> =
-    value(key) { it?.string ?: default }
+public fun MetaProvider.string(default: String, key: Name? = null): MetaDelegate<String> =
+    value(key = key) { it?.string ?: default }
 
-public fun MetaProvider.boolean(default: Boolean, key: Name? = null): ReadOnlyProperty<Any?, Boolean> =
-    value(key) { it?.boolean ?: default }
+public fun MetaProvider.boolean(default: Boolean, key: Name? = null): MetaDelegate<Boolean> =
+    value(key = key) { it?.boolean ?: default }
 
-public fun MetaProvider.number(default: Number, key: Name? = null): ReadOnlyProperty<Any?, Number> =
-    value(key) { it?.numberOrNull ?: default }
+public fun MetaProvider.number(default: Number, key: Name? = null): MetaDelegate<Number> =
+    value(key = key) { it?.numberOrNull ?: default }
 
-public fun MetaProvider.double(default: Double, key: Name? = null): ReadOnlyProperty<Any?, Double> =
-    value(key) { it?.double ?: default }
+public fun MetaProvider.double(default: Double, key: Name? = null): MetaDelegate<Double> =
+    value(key = key) { it?.double ?: default }
 
-public fun MetaProvider.float(default: Float, key: Name? = null): ReadOnlyProperty<Any?, Float> =
-    value(key) { it?.float ?: default }
+public fun MetaProvider.float(default: Float, key: Name? = null): MetaDelegate<Float> =
+    value(key = key) { it?.float ?: default }
 
-public fun MetaProvider.int(default: Int, key: Name? = null): ReadOnlyProperty<Any?, Int> =
-    value(key) { it?.int ?: default }
+public fun MetaProvider.int(default: Int, key: Name? = null): MetaDelegate<Int> =
+    value(key = key) { it?.int ?: default }
 
-public fun MetaProvider.long(default: Long, key: Name? = null): ReadOnlyProperty<Any?, Long> =
-    value(key) { it?.long ?: default }
+public fun MetaProvider.long(default: Long, key: Name? = null): MetaDelegate<Long> =
+    value(key = key) { it?.long ?: default }
 
-public inline fun <reified E : Enum<E>> MetaProvider.enum(default: E, key: Name? = null): ReadOnlyProperty<Any?, E> =
-    value<E>(key) { it?.enum<E>() ?: default }
+public inline fun <reified E : Enum<E>> MetaProvider.enum(default: E, key: Name? = null): MetaDelegate<E> =
+    value<E>(key = key) { it?.enum<E>() ?: default }
 
-public fun MetaProvider.string(key: Name? = null, default: () -> String): ReadOnlyProperty<Any?, String> =
-    value(key) { it?.string ?: default() }
+public fun MetaProvider.string(key: Name? = null, default: () -> String): MetaDelegate<String> =
+    value(key = key) { it?.string ?: default() }
 
-public fun MetaProvider.boolean(key: Name? = null, default: () -> Boolean): ReadOnlyProperty<Any?, Boolean> =
-    value(key) { it?.boolean ?: default() }
+public fun MetaProvider.boolean(key: Name? = null, default: () -> Boolean): MetaDelegate<Boolean> =
+    value(key = key) { it?.boolean ?: default() }
 
-public fun MetaProvider.number(key: Name? = null, default: () -> Number): ReadOnlyProperty<Any?, Number> =
-    value(key) { it?.numberOrNull ?: default() }
+public fun MetaProvider.number(key: Name? = null, default: () -> Number): MetaDelegate<Number> =
+    value(key = key) { it?.numberOrNull ?: default() }

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MetaReader.kt

@@ -0,0 +1,21 @@
+package space.kscience.dataforge.meta
+
+import space.kscience.dataforge.meta.descriptors.Described
+
+public interface MetaReader<out T> : Described {
+
+    /**
+     * Read the source meta into an object and return null if Meta could not be interpreted as a target type
+     */
+    public fun readOrNull(source: Meta): T?
+
+    /**
+     * Read generic read-only meta with this [MetaReader] producing instance of the desired type.
+     * Throws an error if conversion could not be done.
+     */
+    public fun read(source: Meta): T = readOrNull(source) ?: error("Meta $source could not be interpreted by $this")
+}
+
+
+public fun <T : Any> MetaReader<T>.readNullable(item: Meta?): T? = item?.let { read(it) }
+public fun <T> MetaReader<T>.readValue(value: Value): T? = read(Meta(value))

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MetaRef.kt

@@ -0,0 +1,64 @@
+package space.kscience.dataforge.meta
+
+import space.kscience.dataforge.meta.descriptors.Described
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.meta.descriptors.MetaDescriptorBuilder
+import space.kscience.dataforge.misc.DFExperimental
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.asName
+import kotlin.properties.PropertyDelegateProvider
+import kotlin.properties.ReadOnlyProperty
+
+
+/**
+ * A reference to a read-only value of type [T] inside [MetaProvider]
+ */
+@DFExperimental
+public data class MetaRef<T>(
+    public val name: Name,
+    public val converter: MetaConverter<T>,
+    override val descriptor: MetaDescriptor? = converter.descriptor,
+) : Described
+
+@DFExperimental
+public operator fun <T> MetaProvider.get(ref: MetaRef<T>): T? = get(ref.name)?.let { ref.converter.readOrNull(it) }
+
+@DFExperimental
+public operator fun <T> MutableMetaProvider.set(ref: MetaRef<T>, value: T) {
+    set(ref.name, ref.converter.convert(value))
+}
+
+@DFExperimental
+public class MetaSpec(
+    private val configuration: MetaDescriptorBuilder.() -> Unit = {},
+) : Described {
+    private val refs: MutableList<MetaRef<*>> = mutableListOf()
+
+    private fun registerRef(ref: MetaRef<*>) {
+        refs.add(ref)
+    }
+
+    public fun <T> item(
+        converter: MetaConverter<T>,
+        descriptor: MetaDescriptor? = converter.descriptor,
+        key: Name? = null,
+    ): PropertyDelegateProvider<MetaSpec, ReadOnlyProperty<MetaSpec, MetaRef<T>>> =
+        PropertyDelegateProvider { _, property ->
+            val ref = MetaRef(key ?: property.name.asName(), converter, descriptor)
+            registerRef(ref)
+            ReadOnlyProperty { _, _ ->
+                ref
+            }
+        }
+
+    override val descriptor: MetaDescriptor by lazy {
+        MetaDescriptor {
+            refs.forEach { ref ->
+                ref.descriptor?.let {
+                    node(ref.name, ref.descriptor)
+                }
+            }
+            configuration()
+        }
+    }
+}

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MetaTransformation.kt

@@ -1,6 +1,5 @@
-package space.kscience.dataforge.meta.transformations
+package space.kscience.dataforge.meta
 
-import space.kscience.dataforge.meta.*
 import space.kscience.dataforge.misc.DFExperimental
 import space.kscience.dataforge.names.Name
 import kotlin.jvm.JvmInline

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MutableMeta.kt

@@ -19,6 +19,10 @@ public annotation class MetaBuilderMarker
 public interface MutableMetaProvider : MetaProvider, MutableValueProvider {
     override fun get(name: Name): MutableMeta?
     public operator fun set(name: Name, node: Meta?)
+
+    /**
+     * Set value with the given name. Does nothing if value is not changed.
+     */
     override fun setValue(name: Name, value: Value?)
 }
 
@@ -48,11 +52,13 @@ public interface MutableMeta : Meta, MutableMetaProvider {
     }
 
     override fun setValue(name: Name, value: Value?) {
-        getOrCreate(name).value = value
+        if (value != getValue(name)) {
+            getOrCreate(name).value = value
+        }
     }
 
     /**
-     * Get existing node or create a new one
+     * Get an existing node or create a new one
      */
     public fun getOrCreate(name: Name): MutableMeta
 
@@ -122,6 +128,10 @@ public interface MutableMeta : Meta, MutableMetaProvider {
         setValue(Name.parse(this), array.asValue())
     }
 
+    public infix fun String.put(array: ByteArray) {
+        setValue(Name.parse(this), array.asValue())
+    }
+
     public infix fun String.put(repr: MetaRepr) {
         set(Name.parse(this), repr.toMeta())
     }
@@ -165,7 +175,7 @@ public fun MutableMetaProvider.remove(key: String) {
 
 // node setters
 
-public operator fun MutableMetaProvider.set(Key: NameToken, value: Meta): Unit = set(Key.asName(), value)
+public operator fun MutableMetaProvider.set(key: NameToken, value: Meta): Unit = set(key.asName(), value)
 public operator fun MutableMetaProvider.set(key: String, value: Meta): Unit = set(Name.parse(key), value)
 
 
@@ -198,10 +208,8 @@ public operator fun MutableMetaProvider.set(key: String, metas: Iterable<Meta>):
 
 
 /**
- * Update existing mutable node with another node. The rules are following:
- *  * value replaces anything
- *  * node updates node and replaces anything but node
- *  * node list updates node list if number of nodes in the list is the same and replaces anything otherwise
+ * Update the existing mutable node with another node.
+ * Values that are present in the current provider and are missing in [meta] are kept.
  */
 public fun MutableMetaProvider.update(meta: Meta) {
     meta.valueSequence().forEach { (name, value) ->
@@ -222,7 +230,7 @@ public fun <M : MutableTypedMeta<M>> MutableTypedMeta<M>.edit(name: Name, builde
     getOrCreate(name).apply(builder)
 
 /**
- * Set a value at a given [name]. If node does not exist, create it.
+ * Set a value at a given [name]. If a node does not exist, create it.
  */
 public operator fun <M : MutableTypedMeta<M>> MutableTypedMeta<M>.set(name: Name, value: Value?) {
     edit(name) {
@@ -245,6 +253,9 @@ private class MutableMetaImpl(
     value: Value?,
     children: Map<NameToken, Meta> = emptyMap(),
 ) : AbstractObservableMeta(), ObservableMutableMeta {
+
+    override val self get() = this
+
     override var value = value
         @ThreadSafe set(value) {
             val oldValue = field
@@ -324,8 +335,6 @@ private class MutableMetaImpl(
                     //remove child and invalidate if argument is null
                     if (node == null) {
                         children.remove(token)?.removeListener(this)
-                        // old item is not null otherwise we can't be here
-                        invalidate(name)
                     } else {
                         val newNode = wrapItem(node)
                         newNode.adoptBy(this, token)
@@ -335,7 +344,7 @@ private class MutableMetaImpl(
 
                 else -> {
                     val token = name.firstOrNull()!!
-                    //get existing or create new node.
+                    //get an existing node or create a new node.
                     if (items[token] == null) {
                         val newNode = MutableMetaImpl(null)
                         newNode.adoptBy(this, token)
@@ -369,16 +378,37 @@ public fun MutableMeta.append(name: Name, value: Value): Unit = append(name, Met
 
 public fun MutableMeta.append(key: String, value: Value): Unit = append(Name.parse(key), value)
 
+/**
+ * Update all items that exist in the [newMeta] and remove existing items that are missing in [newMeta].
+ * This produces the same result as clearing all items and updating blank meta with a [newMeta], but does not
+ * produce unnecessary invalidation events (if they are supported).
+ */
+public fun MutableMeta.reset(newMeta: Meta) {
+    //remove old items
+    (items.keys - newMeta.items.keys).forEach {
+        remove(it.asName())
+    }
+    newMeta.items.forEach { (token, item)->
+        set(token, item)
+    }
+}
+
 /**
  * Create a mutable copy of this meta. The copy is created even if the Meta is already mutable
  */
-public fun Meta.toMutableMeta(): ObservableMutableMeta = MutableMetaImpl(value, items)
+public fun Meta.toMutableMeta(): MutableMeta =
+    MutableMeta { update(this@toMutableMeta) } //MutableMetaImpl(value, items)
 
 public fun Meta.asMutableMeta(): MutableMeta = (this as? MutableMeta) ?: toMutableMeta()
 
 @JsName("newObservableMutableMeta")
 public fun ObservableMutableMeta(): ObservableMutableMeta = MutableMetaImpl(null)
 
+/**
+ * Create a pre-filled [ObservableMutableMeta]
+ */
+public fun ObservableMutableMeta(content: Meta): ObservableMutableMeta = ObservableMutableMeta { update(content) }
+
 /**
  * Build a [MutableMeta] using given transformation
  */
@@ -387,12 +417,14 @@ public inline fun ObservableMutableMeta(builder: MutableMeta.() -> Unit = {}): O
 
 
 /**
- * Create a copy of this [Meta], optionally applying the given [block].
- * The listeners of the original Config are not retained.
+ * Create a read-only copy of this [Meta]. [modification] is an optional modification applied to [Meta] on copy.
+ *
+ *  The copy does not reflect changes of the initial Meta.
  */
-public inline fun Meta.copy(block: MutableMeta.() -> Unit = {}): Meta =
-    toMutableMeta().apply(block)
-
+public inline fun Meta.copy(modification: MutableMeta.() -> Unit = {}): Meta = Meta {
+    update(this@copy)
+    modification()
+}
 
 private class MutableMetaWithDefault(
     val source: MutableMeta, val default: MetaProvider, val rootName: Name,

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MutableMetaDelegate.kt

@@ -1,52 +1,123 @@
 package space.kscience.dataforge.meta
 
-import space.kscience.dataforge.meta.transformations.MetaConverter
+import space.kscience.dataforge.meta.descriptors.Described
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.misc.DFExperimental
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
+import space.kscience.dataforge.names.getIndexedList
 import kotlin.properties.ReadWriteProperty
 import kotlin.reflect.KProperty
 
+
 /* Read-write delegates */
 
-public fun MutableMetaProvider.node(key: Name? = null): ReadWriteProperty<Any?, Meta?> =
-    object : ReadWriteProperty<Any?, Meta?> {
-        override fun getValue(thisRef: Any?, property: KProperty<*>): Meta? {
-            return get(key ?: property.name.asName())
-        }
+public interface MutableMetaDelegate<T> : ReadWriteProperty<Any?, T>, Described
 
-        override fun setValue(thisRef: Any?, property: KProperty<*>, value: Meta?) {
-            val name = key ?: property.name.asName()
-            set(name, value)
-        }
+public fun MutableMetaProvider.node(
+    key: Name? = null,
+    descriptor: MetaDescriptor? = null,
+): MutableMetaDelegate<Meta?> = object : MutableMetaDelegate<Meta?> {
+
+    override val descriptor: MetaDescriptor? = descriptor
+
+    override fun getValue(thisRef: Any?, property: KProperty<*>): Meta? {
+        return get(key ?: property.name.asName())
     }
 
-public fun <T> MutableMetaProvider.node(key: Name? = null, converter: MetaConverter<T>): ReadWriteProperty<Any?, T?> =
-    object : ReadWriteProperty<Any?, T?> {
-        override fun getValue(thisRef: Any?, property: KProperty<*>): T? {
-            return get(key ?: property.name.asName())?.let { converter.metaToObject(it) }
-        }
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Meta?) {
+        val name = key ?: property.name.asName()
+        set(name, value)
+    }
+}
 
-        override fun setValue(thisRef: Any?, property: KProperty<*>, value: T?) {
-            val name = key ?: property.name.asName()
-            set(name, value?.let { converter.objectToMeta(it) })
-        }
+/**
+ * Use [converter] to transform an object to Meta and back.
+ * Note that mutation of the object does not change Meta.
+ */
+public fun <T> MutableMetaProvider.convertable(
+    converter: MetaConverter<T>,
+    key: Name? = null,
+): MutableMetaDelegate<T?> = object : MutableMetaDelegate<T?> {
+
+    override val descriptor: MetaDescriptor? get() = converter.descriptor
+
+
+    override fun getValue(thisRef: Any?, property: KProperty<*>): T? {
+        val name = key ?: property.name.asName()
+        return get(name)?.let { converter.read(it) }
     }
 
-public fun MutableMetaProvider.value(key: Name? = null): ReadWriteProperty<Any?, Value?> =
-    object : ReadWriteProperty<Any?, Value?> {
-        override fun getValue(thisRef: Any?, property: KProperty<*>): Value? =
-            get(key ?: property.name.asName())?.value
-
-        override fun setValue(thisRef: Any?, property: KProperty<*>, value: Value?) {
-            setValue(key ?: property.name.asName(), value)
-        }
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T?) {
+        val name = key ?: property.name.asName()
+        set(name, value?.let { converter.convert(it) })
     }
+}
+
+@Deprecated("Use convertable", ReplaceWith("convertable(converter, key)"))
+public fun <T> MutableMetaProvider.node(key: Name? = null, converter: MetaConverter<T>): MutableMetaDelegate<T?> =
+    convertable(converter, key)
+
+/**
+ * Use object serializer to transform it to Meta and back.
+ * Note that mutation of the object does not change Meta.
+ */
+@DFExperimental
+public inline fun <reified T> MutableMetaProvider.serializable(
+    descriptor: MetaDescriptor? = null,
+    key: Name? = null,
+): MutableMetaDelegate<T?> = convertable(MetaConverter.serializable(descriptor), key)
+
+/**
+ * Use [converter] to convert a list of same name siblings meta to object and back.
+ * Note that mutation of the object does not change Meta.
+ */
+public fun <T> MutableMeta.listOfConvertable(
+    converter: MetaConverter<T>,
+    key: Name? = null,
+): MutableMetaDelegate<List<T>> = object : MutableMetaDelegate<List<T>> {
+    override val descriptor: MetaDescriptor? = converter.descriptor?.copy(multiple = true)
+
+    override fun getValue(thisRef: Any?, property: KProperty<*>): List<T> {
+        val name = key ?: property.name.asName()
+        return getIndexedList(name).map { converter.read(it) }
+    }
+
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: List<T>) {
+        val name = key ?: property.name.asName()
+        setIndexed(name, value.map { converter.convert(it) })
+    }
+}
+
+@DFExperimental
+public inline fun <reified T> MutableMeta.listOfSerializable(
+    key: Name? = null,
+    descriptor: MetaDescriptor? = null,
+): MutableMetaDelegate<List<T>> = listOfConvertable(MetaConverter.serializable(descriptor), key)
+
+
+public fun MutableMetaProvider.value(
+    key: Name? = null,
+    descriptor: MetaDescriptor? = null,
+): MutableMetaDelegate<Value?> = object : MutableMetaDelegate<Value?> {
+    override val descriptor: MetaDescriptor? = descriptor
+
+    override fun getValue(thisRef: Any?, property: KProperty<*>): Value? =
+        get(key ?: property.name.asName())?.value
+
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Value?) {
+        setValue(key ?: property.name.asName(), value)
+    }
+}
 
 public fun <T> MutableMetaProvider.value(
     key: Name? = null,
     writer: (T) -> Value? = { Value.of(it) },
-    reader: (Value?) -> T
-): ReadWriteProperty<Any?, T> = object : ReadWriteProperty<Any?, T> {
+    descriptor: MetaDescriptor? = null,
+    reader: (Value?) -> T,
+): MutableMetaDelegate<T> = object : MutableMetaDelegate<T> {
+    override val descriptor: MetaDescriptor? = descriptor
+
     override fun getValue(thisRef: Any?, property: KProperty<*>): T =
         reader(get(key ?: property.name.asName())?.value)
 
@@ -57,65 +128,65 @@ public fun <T> MutableMetaProvider.value(
 
 /* Read-write delegates for [MutableItemProvider] */
 
-public fun MutableMetaProvider.string(key: Name? = null): ReadWriteProperty<Any?, String?> =
+public fun MutableMetaProvider.string(key: Name? = null): MutableMetaDelegate<String?> =
     value(key) { it?.string }
 
-public fun MutableMetaProvider.boolean(key: Name? = null): ReadWriteProperty<Any?, Boolean?> =
+public fun MutableMetaProvider.boolean(key: Name? = null): MutableMetaDelegate<Boolean?> =
     value(key) { it?.boolean }
 
-public fun MutableMetaProvider.number(key: Name? = null): ReadWriteProperty<Any?, Number?> =
+public fun MutableMetaProvider.number(key: Name? = null): MutableMetaDelegate<Number?> =
     value(key) { it?.number }
 
-public fun MutableMetaProvider.string(default: String, key: Name? = null): ReadWriteProperty<Any?, String> =
+public fun MutableMetaProvider.string(default: String, key: Name? = null): MutableMetaDelegate<String> =
     value(key) { it?.string ?: default }
 
-public fun MutableMetaProvider.boolean(default: Boolean, key: Name? = null): ReadWriteProperty<Any?, Boolean> =
+public fun MutableMetaProvider.boolean(default: Boolean, key: Name? = null): MutableMetaDelegate<Boolean> =
     value(key) { it?.boolean ?: default }
 
-public fun MutableMetaProvider.number(default: Number, key: Name? = null): ReadWriteProperty<Any?, Number> =
+public fun MutableMetaProvider.number(default: Number, key: Name? = null): MutableMetaDelegate<Number> =
     value(key) { it?.number ?: default }
 
-public fun MutableMetaProvider.string(key: Name? = null, default: () -> String): ReadWriteProperty<Any?, String> =
+public fun MutableMetaProvider.string(key: Name? = null, default: () -> String): MutableMetaDelegate<String> =
     value(key) { it?.string ?: default() }
 
-public fun MutableMetaProvider.boolean(key: Name? = null, default: () -> Boolean): ReadWriteProperty<Any?, Boolean> =
+public fun MutableMetaProvider.boolean(key: Name? = null, default: () -> Boolean): MutableMetaDelegate<Boolean> =
     value(key) { it?.boolean ?: default() }
 
-public fun MutableMetaProvider.number(key: Name? = null, default: () -> Number): ReadWriteProperty<Any?, Number> =
+public fun MutableMetaProvider.number(key: Name? = null, default: () -> Number): MutableMetaDelegate<Number> =
     value(key) { it?.number ?: default() }
 
 public inline fun <reified E : Enum<E>> MutableMetaProvider.enum(
     default: E,
     key: Name? = null,
-): ReadWriteProperty<Any?, E> = value(key) { value -> value?.string?.let { enumValueOf<E>(it) } ?: default }
+): MutableMetaDelegate<E> = value(key) { value -> value?.string?.let { enumValueOf<E>(it) } ?: default }
 
 /* Number delegates */
 
-public fun MutableMetaProvider.int(key: Name? = null): ReadWriteProperty<Any?, Int?> =
+public fun MutableMetaProvider.int(key: Name? = null): MutableMetaDelegate<Int?> =
     value(key) { it?.int }
 
-public fun MutableMetaProvider.double(key: Name? = null): ReadWriteProperty<Any?, Double?> =
+public fun MutableMetaProvider.double(key: Name? = null): MutableMetaDelegate<Double?> =
     value(key) { it?.double }
 
-public fun MutableMetaProvider.long(key: Name? = null): ReadWriteProperty<Any?, Long?> =
+public fun MutableMetaProvider.long(key: Name? = null): MutableMetaDelegate<Long?> =
     value(key) { it?.long }
 
-public fun MutableMetaProvider.float(key: Name? = null): ReadWriteProperty<Any?, Float?> =
+public fun MutableMetaProvider.float(key: Name? = null): MutableMetaDelegate<Float?> =
     value(key) { it?.float }
 
 
 /* Safe number delegates*/
 
-public fun MutableMetaProvider.int(default: Int, key: Name? = null): ReadWriteProperty<Any?, Int> =
+public fun MutableMetaProvider.int(default: Int, key: Name? = null): MutableMetaDelegate<Int> =
     value(key) { it?.int ?: default }
 
-public fun MutableMetaProvider.double(default: Double, key: Name? = null): ReadWriteProperty<Any?, Double> =
+public fun MutableMetaProvider.double(default: Double, key: Name? = null): MutableMetaDelegate<Double> =
     value(key) { it?.double ?: default }
 
-public fun MutableMetaProvider.long(default: Long, key: Name? = null): ReadWriteProperty<Any?, Long> =
+public fun MutableMetaProvider.long(default: Long, key: Name? = null): MutableMetaDelegate<Long> =
     value(key) { it?.long ?: default }
 
-public fun MutableMetaProvider.float(default: Float, key: Name? = null): ReadWriteProperty<Any?, Float> =
+public fun MutableMetaProvider.float(default: Float, key: Name? = null): MutableMetaDelegate<Float> =
     value(key) { it?.float ?: default }
 
 
@@ -124,7 +195,7 @@ public fun MutableMetaProvider.float(default: Float, key: Name? = null): ReadWri
 public fun MutableMetaProvider.stringList(
     vararg default: String,
     key: Name? = null,
-): ReadWriteProperty<Any?, List<String>> = value(
+): MutableMetaDelegate<List<String>> = value(
     key,
     writer = { list -> list.map { str -> str.asValue() }.asValue() },
     reader = { it?.stringList ?: listOf(*default) },
@@ -132,7 +203,7 @@ public fun MutableMetaProvider.stringList(
 
 public fun MutableMetaProvider.stringList(
     key: Name? = null,
-): ReadWriteProperty<Any?, List<String>?> = value(
+): MutableMetaDelegate<List<String>?> = value(
     key,
     writer = { it -> it?.map { str -> str.asValue() }?.asValue() },
     reader = { it?.stringList },
@@ -141,29 +212,18 @@ public fun MutableMetaProvider.stringList(
 public fun MutableMetaProvider.numberList(
     vararg default: Number,
     key: Name? = null,
-): ReadWriteProperty<Any?, List<Number>> = value(
+): MutableMetaDelegate<List<Number>> = value(
     key,
     writer = { it.map { num -> num.asValue() }.asValue() },
     reader = { it?.list?.map { value -> value.numberOrNull ?: Double.NaN } ?: listOf(*default) },
 )
 
-/* A special delegate for double arrays */
-
-
-public fun MutableMetaProvider.doubleArray(
-    vararg default: Double,
-    key: Name? = null,
-): ReadWriteProperty<Any?, DoubleArray> = value(
-    key,
-    writer = { DoubleArrayValue(it) },
-    reader = { it?.doubleArray ?: doubleArrayOf(*default) },
-)
 
 public fun <T> MutableMetaProvider.listValue(
     key: Name? = null,
     writer: (T) -> Value = { Value.of(it) },
     reader: (Value) -> T,
-): ReadWriteProperty<Any?, List<T>?> = value(
+): MutableMetaDelegate<List<T>?> = value(
     key,
     writer = { it?.map(writer)?.asValue() },
     reader = { it?.list?.map(reader) }

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/ObservableMeta.kt

@@ -1,8 +1,10 @@
 package space.kscience.dataforge.meta
 
 import space.kscience.dataforge.misc.ThreadSafe
-import space.kscience.dataforge.names.*
-import kotlin.reflect.KProperty1
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.cutFirst
+import space.kscience.dataforge.names.firstOrNull
+import space.kscience.dataforge.names.isEmpty
 
 
 internal data class MetaListener(
@@ -15,12 +17,15 @@ internal data class MetaListener(
  */
 public interface ObservableMeta : Meta {
     /**
-     * Add change listener to this meta. Owner is declared to be able to remove listeners later. Listener without owner could not be removed
+     * Add change listener to this meta. The Owner is declared to be able to remove listeners later.
+     * Listeners without an owner could be only removed all together.
+     *
+     * `this` object in the listener represents the current state of this meta. The name points to a changed node
      */
     public fun onChange(owner: Any?, callback: Meta.(name: Name) -> Unit)
 
     /**
-     * Remove all listeners belonging to given owner
+     * Remove all listeners belonging to the given [owner]. Passing null removes all listeners.
      */
     public fun removeListener(owner: Any?)
 
@@ -34,6 +39,9 @@ public interface ObservableMeta : Meta {
  * A [Meta] which is both observable and mutable
  */
 public interface ObservableMutableMeta : ObservableMeta, MutableMeta, MutableTypedMeta<ObservableMutableMeta> {
+
+    override val self: ObservableMutableMeta get() = this
+
     override fun getOrCreate(name: Name): ObservableMutableMeta
 
     override fun get(name: Name): ObservableMutableMeta? {
@@ -67,24 +75,4 @@ internal abstract class AbstractObservableMeta : ObservableMeta {
     override fun toString(): String = Meta.toString(this)
     override fun equals(other: Any?): Boolean = Meta.equals(this, other as? Meta)
     override fun hashCode(): Int = Meta.hashCode(this)
-}
-
-/**
- * Use the value of the property in a [callBack].
- * The callback is called once immediately after subscription to pass the initial value.
- *
- * Optional [owner] property is used for
- */
-public fun <S : Scheme, T> S.useProperty(
-    property: KProperty1<S, T>,
-    owner: Any? = null,
-    callBack: S.(T) -> Unit,
-) {
-    //Pass initial value.
-    callBack(property.get(this))
-    meta.onChange(owner) { name ->
-        if (name.startsWith(property.name.asName())) {
-            callBack(property.get(this@useProperty))
-        }
-    }
 }

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/ObservableMetaWrapper.kt

@@ -6,60 +6,74 @@ import space.kscience.dataforge.names.*
 
 /**
  * A class that takes [MutableMeta] provider and adds obsevability on top of that
+ *
+ * TODO rewrite to properly work with detached nodes
  */
 private class ObservableMetaWrapper(
     val root: MutableMeta,
-    val absoluteName: Name,
+    val nodeName: Name,
     val listeners: MutableSet<MetaListener>,
 ) : ObservableMutableMeta {
-    override val items: Map<NameToken, ObservableMutableMeta>
-        get() = root.items.keys.associateWith {
-            ObservableMetaWrapper(root, absoluteName + it, listeners)
-        }
 
-    override fun get(name: Name): ObservableMutableMeta? =
-        root.get(name)?.let { ObservableMetaWrapper(root, this.absoluteName + name, listeners) }
+    override val self get() = this
+
+    override val items: Map<NameToken, ObservableMutableMeta>
+        get() = root[nodeName]?.items?.keys?.associateWith {
+            ObservableMetaWrapper(root, nodeName + it, listeners)
+        } ?: emptyMap()
+
+    override fun get(name: Name): ObservableMutableMeta? = if (root[nodeName + name] == null) {
+        null
+    } else {
+        ObservableMetaWrapper(root, nodeName + name, listeners)
+    }
 
     @ThreadSafe
     override fun onChange(owner: Any?, callback: Meta.(name: Name) -> Unit) {
         listeners.add(
-            MetaListener(Pair(owner, absoluteName)) { name ->
-                if (name.startsWith(absoluteName)) {
-                    (this[absoluteName] ?: Meta.EMPTY).callback(name.removeFirstOrNull(absoluteName)!!)
+            MetaListener(Pair(owner, nodeName)) { fullName ->
+                if (fullName.startsWith(nodeName)) {
+                    root[nodeName]?.callback(fullName.removeFirstOrNull(nodeName)!!)
                 }
             }
         )
     }
 
     override fun removeListener(owner: Any?) {
-        listeners.removeAll { it.owner === Pair(owner, absoluteName) }
+        listeners.removeAll { it.owner === Pair(owner, nodeName) }
     }
 
     override fun invalidate(name: Name) {
-        listeners.forEach { it.callback(this, name) }
+        listeners.forEach { it.callback(this, nodeName + name) }
     }
 
     override var value: Value?
-        get() = root.value
+        get() = root[nodeName]?.value
         set(value) {
-            root.value = value
+            root.getOrCreate(nodeName).value = value
             invalidate(Name.EMPTY)
         }
 
     override fun getOrCreate(name: Name): ObservableMutableMeta =
-        ObservableMetaWrapper(root, this.absoluteName + name, listeners)
+        ObservableMetaWrapper(root, nodeName + name, listeners)
 
-    override fun set(name: Name, node: Meta?) {
+    fun removeNode(name: Name): Meta? {
         val oldMeta = get(name)
         //don't forget to remove listener
         oldMeta?.removeListener(this)
-        root.set(absoluteName + name, node)
+
+        return oldMeta
+    }
+
+    override fun set(name: Name, node: Meta?) {
+        val oldMeta = removeNode(name)
+        root[nodeName + name] = node
         if (oldMeta != node) {
             invalidate(name)
         }
     }
 
-    override fun toMeta(): Meta = root[absoluteName]?.toMeta() ?: Meta.EMPTY
+    override fun toMeta(): Meta = root[nodeName]?.toMeta() ?: Meta.EMPTY
 
     override fun toString(): String = Meta.toString(this)
     override fun equals(other: Any?): Boolean = Meta.equals(this, other as? Meta)

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Scheme.kt

@@ -7,36 +7,45 @@ import space.kscience.dataforge.meta.descriptors.validate
 import space.kscience.dataforge.misc.DFExperimental
 import space.kscience.dataforge.misc.ThreadSafe
 import space.kscience.dataforge.names.*
+import kotlin.properties.ReadWriteProperty
+import kotlin.reflect.KProperty
+import kotlin.reflect.KProperty1
 
 /**
- * A base for delegate-based or descriptor-based scheme. [Scheme] has an empty constructor to simplify usage from [Specification].
- * Default item provider and [MetaDescriptor] are optional
+ * A base for delegate-based or descriptor-based scheme. [Scheme] has an empty constructor to simplify usage from [MetaReader].
+ *
+ * @param prototype default values provided by this scheme
  */
-public open class Scheme : Described, MetaRepr, MutableMetaProvider, Configurable {
+public open class Scheme(
+    private var prototype: Meta? = null,
+    descriptor: MetaDescriptor? = null,
+) : Described, MetaRepr, MutableMetaProvider, Configurable {
 
     /**
-     * Meta to be mutated by this schme
+     * Meta to be mutated by this scheme
      */
-    private var targetMeta: MutableMeta = MutableMeta()
+    internal var target: MutableMeta = MutableMeta()
 
     /**
-     * Default values provided by this scheme
+     * A descriptor of this scheme
      */
-    private var defaultMeta: Meta? = null
+    final override var descriptor: MetaDescriptor? = descriptor
+        private set
+
 
     final override val meta: ObservableMutableMeta = SchemeMeta(Name.EMPTY)
 
-    final override var descriptor: MetaDescriptor? = null
-        internal set
-
-    internal fun wrap(
-        newMeta: MutableMeta,
-        preserveDefault: Boolean = false,
+    /**
+     * This method must be called before the scheme could be used
+     */
+    internal fun initialize(
+        target: MutableMeta,
+        prototype: Meta,
+        descriptor: MetaDescriptor?,
     ) {
-        if (preserveDefault) {
-            defaultMeta = targetMeta.seal()
-        }
-        targetMeta = newMeta
+        this.target = target
+        this.prototype = prototype
+        this.descriptor = descriptor
     }
 
     /**
@@ -47,11 +56,11 @@ public open class Scheme : Described, MetaRepr, MutableMetaProvider, Configurabl
         return descriptor?.validate(meta) ?: true
     }
 
-    override fun get(name: Name): MutableMeta? = meta.get(name)
+    override fun get(name: Name): MutableMeta? = meta[name]
 
     override fun set(name: Name, node: Meta?) {
         if (validate(name, meta)) {
-            meta.set(name, node)
+            meta[name] = node
         } else {
             error("Validation failed for node $node at $name")
         }
@@ -68,14 +77,19 @@ public open class Scheme : Described, MetaRepr, MutableMetaProvider, Configurabl
 
     private val listeners: MutableList<MetaListener> = mutableListOf()
 
+    override fun toString(): String = meta.toString()
+
     private inner class SchemeMeta(val pathName: Name) : ObservableMutableMeta {
+
+        override val self get() = this
+
         override var value: Value?
-            get() = targetMeta[pathName]?.value
-                ?: defaultMeta?.get(pathName)?.value
+            get() = target[pathName]?.value
+                ?: prototype?.get(pathName)?.value
                 ?: descriptor?.get(pathName)?.defaultValue
             set(value) {
-                val oldValue = targetMeta[pathName]?.value
-                targetMeta[pathName] = value
+                val oldValue = target[pathName]?.value
+                target[pathName] = value
                 if (oldValue != value) {
                     invalidate(Name.EMPTY)
                 }
@@ -83,8 +97,8 @@ public open class Scheme : Described, MetaRepr, MutableMetaProvider, Configurabl
 
         override val items: Map<NameToken, ObservableMutableMeta>
             get() {
-                val targetKeys = targetMeta[pathName]?.items?.keys ?: emptySet()
-                val defaultKeys = defaultMeta?.get(pathName)?.items?.keys ?: emptySet()
+                val targetKeys = target[pathName]?.items?.keys ?: emptySet()
+                val defaultKeys = prototype?.get(pathName)?.items?.keys ?: emptySet()
                 return (targetKeys + defaultKeys).associateWith { SchemeMeta(pathName + it) }
             }
 
@@ -111,7 +125,7 @@ public open class Scheme : Described, MetaRepr, MutableMetaProvider, Configurabl
         override fun hashCode(): Int = Meta.hashCode(this)
 
         override fun set(name: Name, node: Meta?) {
-            targetMeta.set(name, node)
+            target[pathName + name] = node
             invalidate(name)
         }
 
@@ -119,7 +133,6 @@ public open class Scheme : Described, MetaRepr, MutableMetaProvider, Configurabl
 
         @DFExperimental
         override fun attach(name: Name, node: ObservableMutableMeta) {
-            //TODO implement zero-copy attachment
             set(name, node)
             node.onChange(this) { changeName ->
                 set(name + changeName, this[changeName])
@@ -131,10 +144,11 @@ public open class Scheme : Described, MetaRepr, MutableMetaProvider, Configurabl
 
 /**
  * Relocate scheme target onto given [MutableMeta]. Old provider does not get updates anymore.
- * Current state of the scheme used as a default.
+ * The Current state of the scheme that os used as a default.
  */
+@DFExperimental
 public fun <T : Scheme> T.retarget(provider: MutableMeta): T = apply {
-    wrap(provider, true)
+    initialize(provider, meta.seal(), descriptor)
 }
 
 /**
@@ -151,26 +165,150 @@ public inline fun <T : Scheme> T.copy(spec: SchemeSpec<T>, block: T.() -> Unit =
 /**
  * A specification for simplified generation of wrappers
  */
-public open class SchemeSpec<out T : Scheme>(
+public open class SchemeSpec<T : Scheme>(
     private val builder: () -> T,
-) : Specification<T> {
+) : MetaConverter<T> {
 
-    override fun read(source: Meta): T = builder().also {
-        it.wrap(MutableMeta().withDefault(source))
-    }
-
-    override fun write(target: MutableMeta): T = empty().also {
-        it.wrap(target)
-    }
-
-    //TODO Generate descriptor from Scheme class
     override val descriptor: MetaDescriptor? get() = null
 
-    override fun empty(): T = builder().also {
-        it.descriptor = descriptor
+    override fun readOrNull(source: Meta): T = builder().also {
+        it.initialize(MutableMeta(), source, descriptor)
     }
 
-    @Suppress("OVERRIDE_BY_INLINE")
-    final override inline operator fun invoke(action: T.() -> Unit): T = empty().apply(action)
+    /**
+     * Write changes made to the [Scheme] to target [MutableMeta]. If the empty [Scheme] contains any data it is copied to the target.
+     */
+    public fun write(target: MutableMeta): T = empty().also {
+        target.update(it.meta)
+        it.initialize(target, Meta.EMPTY, descriptor)
+    }
 
+    /**
+     * Generate a blank object. The object could contain some elements if they are defined in a constructor
+     */
+    public fun empty(): T = builder().also {
+        it.initialize(MutableMeta(), it.target, descriptor)
+    }
+
+    override fun convert(obj: T): Meta = obj.meta
+
+    /**
+     * A convenience method to use specifications in builders
+     */
+    public inline operator fun invoke(action: T.() -> Unit): T = empty().apply(action)
+
+}
+
+
+/**
+ * Update a [MutableMeta] using given specification
+ */
+public fun <T : Scheme> MutableMeta.updateWith(
+    spec: SchemeSpec<T>,
+    action: T.() -> Unit,
+): T = spec.write(this).apply(action)
+
+
+/**
+ * Update configuration using given specification
+ */
+public fun <T : Scheme> Configurable.updateWith(
+    spec: SchemeSpec<T>,
+    action: T.() -> Unit,
+): T = spec.write(meta).apply(action)
+
+
+/**
+ * A delegate that uses a [MetaReader] to wrap a child of this provider
+ */
+public fun <T : Scheme> MutableMeta.scheme(
+    spec: SchemeSpec<T>,
+    key: Name? = null,
+): ReadWriteProperty<Any?, T> = object : ReadWriteProperty<Any?, T> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): T {
+        val name = key ?: property.name.asName()
+        return spec.write(getOrCreate(name))
+    }
+
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
+        val name = key ?: property.name.asName()
+        set(name, value.toMeta())
+    }
+}
+
+public fun <T : Scheme> Scheme.scheme(
+    spec: SchemeSpec<T>,
+    key: Name? = null,
+): ReadWriteProperty<Any?, T> = meta.scheme(spec, key)
+
+/**
+ * A delegate that uses a [MetaReader] to wrap a child of this provider.
+ * Returns null if meta with given name does not exist.
+ */
+public fun <T : Scheme> MutableMeta.schemeOrNull(
+    spec: SchemeSpec<T>,
+    key: Name? = null,
+): ReadWriteProperty<Any?, T?> = object : ReadWriteProperty<Any?, T?> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): T? {
+        val name = key ?: property.name.asName()
+        return if (get(name) == null) null else spec.write(getOrCreate(name))
+    }
+
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T?) {
+        val name = key ?: property.name.asName()
+        if (value == null) remove(name)
+        else set(name, value.toMeta())
+    }
+}
+
+public fun <T : Scheme> Scheme.schemeOrNull(
+    spec: SchemeSpec<T>,
+    key: Name? = null,
+): ReadWriteProperty<Any?, T?> = meta.schemeOrNull(spec, key)
+
+/**
+ * A delegate that uses a [MetaReader] to wrap a list of child providers.
+ * If children are mutable, the changes in list elements are reflected on them.
+ * The list is a snapshot of children state, so change in structure is not reflected on its composition.
+ */
+public fun <T : Scheme> MutableMeta.listOfScheme(
+    spec: SchemeSpec<T>,
+    key: Name? = null,
+): ReadWriteProperty<Any?, List<T>> = object : ReadWriteProperty<Any?, List<T>> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): List<T> {
+        val name = key ?: property.name.asName()
+        return getIndexedList(name).map { spec.write(it as MutableMeta) }
+    }
+
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: List<T>) {
+        val name = key ?: property.name.asName()
+        setIndexed(name, value.map { it.toMeta() })
+    }
+}
+
+
+public fun <T : Scheme> Scheme.listOfScheme(
+    spec: SchemeSpec<T>,
+    key: Name? = null,
+): ReadWriteProperty<Any?, List<T>> = meta.listOfScheme(spec, key)
+
+
+/**
+ * Use the value of the property in a [callBack].
+ * The callback is called once immediately after subscription to pass the initial value.
+ *
+ * Optional [owner] property is used for
+ */
+public fun <S : Scheme, T> S.useProperty(
+    property: KProperty1<S, T>,
+    owner: Any? = null,
+    callBack: S.(T) -> Unit,
+) {
+    //Pass initial value.
+    callBack(property.get(this))
+    meta.onChange(owner) { name ->
+        if (name.startsWith(property.name.asName())) {
+            callBack(property.get(this@useProperty))
+        }
+    }
 }

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/SealedMeta.kt

@@ -13,6 +13,9 @@ public class SealedMeta(
     override val value: Value?,
     override val items: Map<NameToken, SealedMeta>,
 ) : TypedMeta<SealedMeta> {
+
+    override val self: SealedMeta get() = this
+
     override fun toString(): String = Meta.toString(this)
     override fun equals(other: Any?): Boolean = Meta.equals(this, other as? Meta)
 
@@ -76,6 +79,8 @@ internal class MetaBuilder(
 
 
     override fun set(name: Name, node: Meta?) {
+        //skip setting if value has not changed
+        if(node == get(name)) return
         when (name.length) {
             0 -> error("Can't set a meta with empty name")
             1 -> {
@@ -89,7 +94,7 @@ internal class MetaBuilder(
             }
 
             else -> {
-                getOrCreate(name.first().asName()).set(name.cutFirst(), node)
+                getOrCreate(name.first().asName())[name.cutFirst()] = node
             }
         }
     }
@@ -101,11 +106,6 @@ internal class MetaBuilder(
     override fun hashCode(): Int = Meta.hashCode(this)
 }
 
-/**
- * Create a read-only meta.
- */
-public inline fun Meta(builder: MutableMeta.() -> Unit): Meta =
-    MetaBuilder().apply(builder).seal()
 
 /**
  * Create an immutable meta.
@@ -113,6 +113,11 @@ public inline fun Meta(builder: MutableMeta.() -> Unit): Meta =
 public inline fun SealedMeta(builder: MutableMeta.() -> Unit): SealedMeta =
     MetaBuilder().apply(builder).seal()
 
+/**
+ * Create a read-only meta.
+ */
+public inline fun Meta(builder: MutableMeta.() -> Unit): Meta = SealedMeta(builder)
+
 /**
  * Create an empty meta mutable meta.
  */

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Specification.kt

@@ -1,130 +0,0 @@
-package space.kscience.dataforge.meta
-
-import space.kscience.dataforge.meta.descriptors.Described
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.asName
-import kotlin.properties.ReadWriteProperty
-import kotlin.reflect.KProperty
-
-public interface ReadOnlySpecification<out T : Any>: Described {
-
-    /**
-     * Read generic read-only meta with this [Specification] producing instance of desired type.
-     * The source is not mutated even if it is in theory mutable
-     */
-    public fun read(source: Meta): T
-
-    /**
-     * Generate an empty object
-     */
-    public fun empty(): T
-
-    /**
-     * A convenience method to use specifications in builders
-     */
-    public operator fun invoke(action: T.() -> Unit): T = empty().apply(action)
-}
-
-
-/**
- * Allows to apply custom configuration in a type safe way to simple untyped configuration.
- * By convention [Scheme] companion should inherit this class
- *
- */
-public interface Specification<out T : Any> : ReadOnlySpecification<T> {
-    /**
-     * Wrap [MutableMeta], using it as inner storage (changes to [Specification] are reflected on [MutableMeta]
-     */
-    public fun write(target: MutableMeta): T
-}
-
-/**
- * Update a [MutableMeta] using given specification
- */
-public fun <T : Any> MutableMeta.updateWith(
-    spec: Specification<T>,
-    action: T.() -> Unit,
-): T = spec.write(this).apply(action)
-
-
-/**
- * Update configuration using given specification
- */
-public fun <T : Any> Configurable.updateWith(
-    spec: Specification<T>,
-    action: T.() -> Unit,
-): T = spec.write(meta).apply(action)
-
-//
-//public fun  <M : MutableTypedMeta<M>> MutableMeta.withSpec(spec: Specification<M>): M? =
-//    spec.write(it)
-
-/**
- * A delegate that uses a [Specification] to wrap a child of this provider
- */
-public fun <T : Scheme> MutableMeta.spec(
-    spec: Specification<T>,
-    key: Name? = null,
-): ReadWriteProperty<Any?, T> = object : ReadWriteProperty<Any?, T> {
-    override fun getValue(thisRef: Any?, property: KProperty<*>): T {
-        val name = key ?: property.name.asName()
-        return spec.write(getOrCreate(name))
-    }
-
-    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
-        val name = key ?: property.name.asName()
-        set(name, value.toMeta())
-    }
-}
-
-public fun <T : Scheme> Scheme.spec(
-    spec: Specification<T>,
-    key: Name? = null,
-): ReadWriteProperty<Any?, T> = meta.spec(spec, key)
-
-/**
- * A delegate that uses a [Specification] to wrap a child of this provider.
- * Returns null if meta with given name does not exist.
- */
-public fun <T : Scheme> MutableMeta.specOrNull(
-    spec: Specification<T>,
-    key: Name? = null,
-): ReadWriteProperty<Any?, T?> = object : ReadWriteProperty<Any?, T?> {
-    override fun getValue(thisRef: Any?, property: KProperty<*>): T? {
-        val name = key ?: property.name.asName()
-        return if (get(name) == null) null else spec.write(getOrCreate(name))
-    }
-
-    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T?) {
-        val name = key ?: property.name.asName()
-        if (value == null) remove(name)
-        else set(name, value.toMeta())
-    }
-}
-
-public fun <T : Scheme> Scheme.specOrNull(
-    spec: Specification<T>,
-    key: Name? = null,
-): ReadWriteProperty<Any?, T?> = meta.specOrNull(spec, key)
-
-/**
- * A delegate that uses a [Specification] to wrap a list of child providers.
- * If children are mutable, the changes in list elements are reflected on them.
- * The list is a snapshot of children state, so change in structure is not reflected on its composition.
- */
-@DFExperimental
-public fun <T : Scheme> MutableMeta.listOfSpec(
-    spec: Specification<T>,
-    key: Name? = null,
-): ReadWriteProperty<Any?, List<T>> = object : ReadWriteProperty<Any?, List<T>> {
-    override fun getValue(thisRef: Any?, property: KProperty<*>): List<T> {
-        val name = key ?: property.name.asName()
-        return getIndexed(name).values.map { spec.write(it as MutableMeta) }
-    }
-
-    override fun setValue(thisRef: Any?, property: KProperty<*>, value: List<T>) {
-        val name = key ?: property.name.asName()
-        setIndexed(name, value.map { it.toMeta() })
-    }
-}

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Value.kt

@@ -256,8 +256,6 @@ public fun ShortArray.asValue(): Value = if (isEmpty()) Null else ListValue(map
 
 public fun FloatArray.asValue(): Value = if (isEmpty()) Null else ListValue(map { NumberValue(it) })
 
-public fun ByteArray.asValue(): Value = if (isEmpty()) Null else ListValue(map { NumberValue(it) })
-
 public fun <E : Enum<E>> E.asValue(): Value = EnumValue(this)
 
 

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/descriptors/MetaDescriptor.kt

@@ -7,6 +7,7 @@ import space.kscience.dataforge.names.*
 /**
  * Restrictions on value in the node
  */
+@Serializable
 public enum class ValueRestriction {
     /**
      * No restrictions
@@ -27,7 +28,7 @@ public enum class ValueRestriction {
 /**
  * The descriptor for a meta
  * @param description description text
- * @param children child descriptors for this node
+ * @param nodes child descriptors for this node
  * @param multiple True if same name siblings with this name are allowed
  * @param valueRestriction The requirements for node content
  * @param valueTypes list of allowed types for [Meta.value], null if all values are allowed.
@@ -39,7 +40,7 @@ public enum class ValueRestriction {
 @Serializable
 public data class MetaDescriptor(
     public val description: String? = null,
-    public val children: Map<String, MetaDescriptor> = emptyMap(),
+    public val nodes: Map<String, MetaDescriptor> = emptyMap(),
     public val multiple: Boolean = false,
     public val valueRestriction: ValueRestriction = ValueRestriction.NONE,
     public val valueTypes: List<ValueType>? = null,
@@ -47,6 +48,9 @@ public data class MetaDescriptor(
     public val defaultValue: Value? = null,
     public val attributes: Meta = Meta.EMPTY,
 ) {
+    @Deprecated("Replace by nodes", ReplaceWith("nodes"))
+    public val children: Map<String, MetaDescriptor> get() = nodes
+
     /**
      * A node constructed of default values for this descriptor and its children
      */
@@ -55,7 +59,7 @@ public data class MetaDescriptor(
             defaultValue?.let { defaultValue ->
                 this.value = defaultValue
             }
-            children.forEach { (key, descriptor) ->
+            nodes.forEach { (key, descriptor) ->
                 set(key, descriptor.defaultNode)
             }
         }
@@ -67,13 +71,13 @@ public data class MetaDescriptor(
     }
 }
 
-public val MetaDescriptor.required: Boolean get() = valueRestriction == ValueRestriction.REQUIRED || children.values.any { required }
+public val MetaDescriptor.required: Boolean get() = valueRestriction == ValueRestriction.REQUIRED || nodes.values.any { required }
 
 public val MetaDescriptor.allowedValues: List<Value>? get() = attributes[MetaDescriptor.ALLOWED_VALUES_KEY]?.value?.list
 
 public operator fun MetaDescriptor.get(name: Name): MetaDescriptor? = when (name.length) {
     0 -> this
-    1 -> children[name.firstOrNull()!!.toString()]
+    1 -> nodes[name.firstOrNull()!!.toString()]
     else -> get(name.firstOrNull()!!.asName())?.get(name.cutFirst())
 }
 
@@ -95,7 +99,7 @@ public fun MetaDescriptor.validate(item: Meta?): Boolean {
     if (item == null) return !required
     if (!validate(item.value)) return false
 
-    children.forEach { (key, childDescriptor) ->
+    nodes.forEach { (key, childDescriptor) ->
         if (!childDescriptor.validate(item[key])) return false
     }
     return true

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/descriptors/MetaDescriptorBuilder.kt

@@ -9,7 +9,8 @@ import space.kscience.dataforge.names.length
 import kotlin.collections.set
 
 public class MetaDescriptorBuilder @PublishedApi internal constructor() {
-    public var info: String? = null
+    public var description: String? = null
+
     public var children: MutableMap<String, MetaDescriptorBuilder> = linkedMapOf()
     public var multiple: Boolean = false
     public var valueRestriction: ValueRestriction = ValueRestriction.NONE
@@ -40,38 +41,28 @@ public class MetaDescriptorBuilder @PublishedApi internal constructor() {
         attributes.apply(block)
     }
 
-    public fun item(name: Name, block: MetaDescriptorBuilder.() -> Unit = {}): MetaDescriptorBuilder {
-        return when (name.length) {
-            0 -> apply(block)
+    internal fun node(
+        name: Name,
+        descriptorBuilder: MetaDescriptorBuilder,
+    ): Unit {
+        when (name.length) {
+            0 -> error("Can't set descriptor to root")
+
             1 -> {
-                val target = MetaDescriptorBuilder().apply(block)
-                children[name.first().body] = target
-                target
+                children[name.first().body] = descriptorBuilder
             }
 
-            else -> {
-                children.getOrPut(name.first().body) { MetaDescriptorBuilder() }.item(name.cutFirst(), block)
-            }
+            else -> children.getOrPut(name.first().body) {
+                MetaDescriptorBuilder()
+            }.node(name.cutFirst(), descriptorBuilder)
         }
     }
 
     public fun node(
         name: Name,
-        descriptor: MetaDescriptor,
-        block: MetaDescriptorBuilder.() -> Unit = {},
-    ): MetaDescriptorBuilder = when (name.length) {
-        0 -> error("Can't set descriptor to root")
-        1 -> {
-            val item = descriptor.toBuilder().apply {
-                valueRestriction = ValueRestriction.ABSENT
-            }.apply(block)
-            children[name.first().body] = item
-            item
-        }
-
-        else -> children.getOrPut(name.first().body) {
-            MetaDescriptorBuilder()
-        }.node(name.cutFirst(), descriptor, block)
+        descriptorBuilder: MetaDescriptor,
+    ): Unit {
+        node(name, descriptorBuilder.toBuilder())
     }
 
     public var allowedValues: List<Value>
@@ -85,10 +76,21 @@ public class MetaDescriptorBuilder @PublishedApi internal constructor() {
         allowedValues = values.map { Value.of(it) }
     }
 
+    public fun from(descriptor: MetaDescriptor) {
+        description = descriptor.description
+        children.putAll(descriptor.nodes.mapValues { it.value.toBuilder() })
+        multiple = descriptor.multiple
+        valueRestriction = descriptor.valueRestriction
+        valueTypes = descriptor.valueTypes
+        indexKey = descriptor.indexKey
+        default = descriptor.defaultValue
+        attributes.update(descriptor.attributes)
+    }
+
     @PublishedApi
     internal fun build(): MetaDescriptor = MetaDescriptor(
-        description = info,
-        children = children.mapValues { it.value.build() },
+        description = description,
+        nodes = children.mapValues { it.value.build() },
         multiple = multiple,
         valueRestriction = valueRestriction,
         valueTypes = valueTypes,
@@ -98,12 +100,57 @@ public class MetaDescriptorBuilder @PublishedApi internal constructor() {
     )
 }
 
-public fun MetaDescriptorBuilder.item(name: String, block: MetaDescriptorBuilder.() -> Unit): MetaDescriptorBuilder =
-    item(Name.parse(name), block)
+//public fun MetaDescriptorBuilder.item(name: String, block: MetaDescriptorBuilder.() -> Unit): MetaDescriptorBuilder =
+//    item(Name.parse(name), block)
 
 public inline fun MetaDescriptor(block: MetaDescriptorBuilder.() -> Unit): MetaDescriptor =
     MetaDescriptorBuilder().apply(block).build()
 
+/**
+ * Create and configure child node descriptor
+ */
+public fun MetaDescriptorBuilder.node(
+    name: Name,
+    block: MetaDescriptorBuilder.() -> Unit,
+) {
+    node(
+        name,
+        MetaDescriptorBuilder().apply(block)
+    )
+}
+
+public fun MetaDescriptorBuilder.node(name: String, descriptor: MetaDescriptor) {
+    node(Name.parse(name), descriptor)
+}
+
+public fun MetaDescriptorBuilder.node(name: String, block: MetaDescriptorBuilder.() -> Unit) {
+    node(Name.parse(name), block)
+}
+
+public fun MetaDescriptorBuilder.node(
+    key: String,
+    base: Described,
+    block: MetaDescriptorBuilder.() -> Unit = {},
+) {
+    node(Name.parse(key), base.descriptor?.toBuilder()?.apply(block) ?: MetaDescriptorBuilder())
+}
+
+public fun MetaDescriptorBuilder.required() {
+    valueRestriction = ValueRestriction.REQUIRED
+}
+
+private fun MetaDescriptor.toBuilder(): MetaDescriptorBuilder = MetaDescriptorBuilder().apply {
+    description = this@toBuilder.description
+    children = this@toBuilder.nodes.mapValuesTo(LinkedHashMap()) { it.value.toBuilder() }
+    multiple = this@toBuilder.multiple
+    valueRestriction = this@toBuilder.valueRestriction
+    valueTypes = this@toBuilder.valueTypes
+    indexKey = this@toBuilder.indexKey
+    default = defaultValue
+    attributes = this@toBuilder.attributes.toMutableMeta()
+}
+
+
 /**
  * Create and configure child value descriptor
  */
@@ -112,7 +159,7 @@ public fun MetaDescriptorBuilder.value(
     type: ValueType,
     vararg additionalTypes: ValueType,
     block: MetaDescriptorBuilder.() -> Unit = {},
-): MetaDescriptorBuilder = item(name) {
+): Unit = node(name) {
     valueType(type, *additionalTypes)
     block()
 }
@@ -122,41 +169,14 @@ public fun MetaDescriptorBuilder.value(
     type: ValueType,
     vararg additionalTypes: ValueType,
     block: MetaDescriptorBuilder.() -> Unit = {},
-): MetaDescriptorBuilder = value(Name.parse(name), type, additionalTypes = additionalTypes, block)
+): Unit = value(Name.parse(name), type, additionalTypes = additionalTypes, block)
 
-/**
- * Create and configure child value descriptor
- */
-public fun MetaDescriptorBuilder.node(
-    name: Name, block: MetaDescriptorBuilder.() -> Unit,
-): MetaDescriptorBuilder = item(name) {
-    valueRestriction = ValueRestriction.ABSENT
-    block()
-}
-
-public fun MetaDescriptorBuilder.node(name: String, block: MetaDescriptorBuilder.() -> Unit) {
-    node(Name.parse(name), block)
-}
-
-public fun MetaDescriptorBuilder.node(
-    key: String,
-    described: Described,
-    block: MetaDescriptorBuilder.() -> Unit = {},
-) {
-    described.descriptor?.let {
-        node(Name.parse(key), it, block)
-    }
-}
-
-public fun MetaDescriptorBuilder.required() {
-    valueRestriction = ValueRestriction.REQUIRED
-}
 
 public inline fun <reified E : Enum<E>> MetaDescriptorBuilder.enum(
     key: Name,
     default: E?,
     crossinline modifier: MetaDescriptorBuilder.() -> Unit = {},
-): MetaDescriptorBuilder = value(key, ValueType.STRING) {
+): Unit = value(key, ValueType.STRING) {
     default?.let {
         this.default = default.asValue()
     }
@@ -164,17 +184,6 @@ public inline fun <reified E : Enum<E>> MetaDescriptorBuilder.enum(
     modifier()
 }
 
-private fun MetaDescriptor.toBuilder(): MetaDescriptorBuilder = MetaDescriptorBuilder().apply {
-    info = this@toBuilder.description
-    children = this@toBuilder.children.mapValuesTo(LinkedHashMap()) { it.value.toBuilder() }
-    multiple = this@toBuilder.multiple
-    valueRestriction = this@toBuilder.valueRestriction
-    valueTypes = this@toBuilder.valueTypes
-    indexKey = this@toBuilder.indexKey
-    default = defaultValue
-    attributes = this@toBuilder.attributes.toMutableMeta()
-}
-
 /**
  * Make a deep copy of this descriptor applying given transformation [block]
  */

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/descriptors/schemeDescriptor.kt

@@ -6,10 +6,13 @@ import space.kscience.dataforge.meta.ValueType
 import kotlin.reflect.KProperty1
 import kotlin.reflect.typeOf
 
+/**
+ * Add a value item to a [MetaDescriptor] inferring some of its properties from the type
+ */
 public inline fun <S : Scheme, reified T> MetaDescriptorBuilder.value(
     property: KProperty1<S, T>,
     noinline block: MetaDescriptorBuilder.() -> Unit = {},
-): MetaDescriptorBuilder = when (typeOf<T>()) {
+): Unit = when (typeOf<T>()) {
     typeOf<Number>(), typeOf<Int>(), typeOf<Double>(), typeOf<Short>(), typeOf<Long>(), typeOf<Float>() ->
         value(property.name, ValueType.NUMBER) {
             block()
@@ -34,9 +37,12 @@ public inline fun <S : Scheme, reified T> MetaDescriptorBuilder.value(
         multiple = true
         block()
     }
-    else -> item(property.name, block)
+    else -> node(property.name, block)
 }
 
+/**
+ * Add a schem-based branch to a [MetaDescriptor]
+ */
 public inline fun <S : Scheme, reified T : Scheme> MetaDescriptorBuilder.scheme(
     property: KProperty1<S, T>,
     spec: SchemeSpec<T>,

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/exoticValues.kt

@@ -1,5 +1,9 @@
 package space.kscience.dataforge.meta
 
+import space.kscience.dataforge.names.Name
+import kotlin.properties.ReadOnlyProperty
+import kotlin.properties.ReadWriteProperty
+
 
 /**
  * A value built from string which content and type are parsed on-demand
@@ -44,3 +48,79 @@ public class DoubleArrayValue(override val value: DoubleArray) : Value, Iterable
 }
 
 public fun DoubleArray.asValue(): Value = if (isEmpty()) Null else DoubleArrayValue(this)
+
+public val Value.doubleArray: DoubleArray
+    get() = if (this is DoubleArrayValue) {
+        value
+    } else {
+        DoubleArray(list.size) { list[it].double }
+    }
+
+public val Meta?.doubleArray: DoubleArray? get() = this?.value?.doubleArray
+
+public fun MetaProvider.doubleArray(
+    vararg default: Double,
+    key: Name? = null,
+): ReadOnlyProperty<Any?, DoubleArray> = value(
+    key,
+    reader = { it?.doubleArray ?: doubleArrayOf(*default) },
+)
+
+public fun MutableMetaProvider.doubleArray(
+    vararg default: Double,
+    key: Name? = null,
+): ReadWriteProperty<Any?, DoubleArray> = value(
+    key,
+    writer = { DoubleArrayValue(it) },
+    reader = { it?.doubleArray ?: doubleArrayOf(*default) },
+)
+
+
+public class ByteArrayValue(override val value: ByteArray) : Value, Iterable<Byte> {
+    override val type: ValueType get() = ValueType.LIST
+    override val list: List<Value> get() = value.map { NumberValue(it) }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is Value) return false
+
+        return when (other) {
+            is ByteArrayValue -> value.contentEquals(other.value)
+            else -> list == other.list
+        }
+    }
+
+    override fun hashCode(): Int = value.contentHashCode()
+
+    override fun toString(): String = list.joinToString(prefix = "[", postfix = "]")
+
+    override fun iterator(): Iterator<Byte> = value.iterator()
+}
+
+public fun ByteArray.asValue(): Value = ByteArrayValue(this)
+
+public val Value.byteArray: ByteArray
+    get() = if (this is ByteArrayValue) {
+        value
+    } else {
+        ByteArray(list.size) { list[it].number.toByte() }
+    }
+
+public val Meta?.byteArray: ByteArray? get() = this?.value?.byteArray
+
+public fun MetaProvider.byteArray(
+    vararg default: Byte,
+    key: Name? = null,
+): ReadOnlyProperty<Any?, ByteArray> = value(
+    key,
+    reader = { it?.byteArray ?: byteArrayOf(*default) },
+)
+
+public fun MutableMetaProvider.byteArray(
+    vararg default: Byte,
+    key: Name? = null,
+): ReadWriteProperty<Any?, ByteArray> = value(
+    key,
+    writer = { ByteArrayValue(it) },
+    reader = { it?.byteArray ?: byteArrayOf(*default) },
+)

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/transformations/MetaConverter.kt

@@ -1,163 +0,0 @@
-package space.kscience.dataforge.meta.transformations
-
-import space.kscience.dataforge.meta.*
-import space.kscience.dataforge.meta.descriptors.MetaDescriptor
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
-
-/**
- * A converter of generic object to and from [Meta]
- */
-public interface MetaConverter<T> {
-
-    /**
-     * Runtime type of [T]
-     */
-    public val type: KType
-
-    /**
-     * A descriptor for resulting meta
-     */
-    public val descriptor: MetaDescriptor get() = MetaDescriptor.EMPTY
-
-    /**
-     * Attempt conversion of [meta] to an object or return null if conversion failed
-     */
-    public fun metaToObjectOrNull(meta: Meta): T?
-
-    public fun metaToObject(meta: Meta): T =
-        metaToObjectOrNull(meta) ?: error("Meta $meta could not be interpreted by $this")
-
-    public fun objectToMeta(obj: T): Meta
-
-    public companion object {
-
-        public val meta: MetaConverter<Meta> = object : MetaConverter<Meta> {
-            override val type: KType = typeOf<Meta>()
-
-            override fun metaToObjectOrNull(meta: Meta): Meta = meta
-            override fun objectToMeta(obj: Meta): Meta = obj
-        }
-
-        public val value: MetaConverter<Value> = object : MetaConverter<Value> {
-            override val type: KType = typeOf<Value>()
-
-            override fun metaToObjectOrNull(meta: Meta): Value? = meta.value
-            override fun objectToMeta(obj: Value): Meta = Meta(obj)
-        }
-
-        public val string: MetaConverter<String> = object : MetaConverter<String> {
-            override val type: KType = typeOf<String>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.STRING)
-            }
-
-
-            override fun metaToObjectOrNull(meta: Meta): String? = meta.string
-            override fun objectToMeta(obj: String): Meta = Meta(obj.asValue())
-        }
-
-        public val boolean: MetaConverter<Boolean> = object : MetaConverter<Boolean> {
-            override val type: KType = typeOf<Boolean>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.BOOLEAN)
-            }
-
-            override fun metaToObjectOrNull(meta: Meta): Boolean? = meta.boolean
-            override fun objectToMeta(obj: Boolean): Meta = Meta(obj.asValue())
-        }
-
-        public val number: MetaConverter<Number> = object : MetaConverter<Number> {
-            override val type: KType = typeOf<Number>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.NUMBER)
-            }
-
-            override fun metaToObjectOrNull(meta: Meta): Number? = meta.number
-            override fun objectToMeta(obj: Number): Meta = Meta(obj.asValue())
-        }
-
-        public val double: MetaConverter<Double> = object : MetaConverter<Double> {
-            override val type: KType = typeOf<Double>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.NUMBER)
-            }
-
-            override fun metaToObjectOrNull(meta: Meta): Double? = meta.double
-            override fun objectToMeta(obj: Double): Meta = Meta(obj.asValue())
-        }
-
-        public val float: MetaConverter<Float> = object : MetaConverter<Float> {
-            override val type: KType = typeOf<Float>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.NUMBER)
-            }
-
-            override fun metaToObjectOrNull(meta: Meta): Float? = meta.float
-            override fun objectToMeta(obj: Float): Meta = Meta(obj.asValue())
-        }
-
-        public val int: MetaConverter<Int> = object : MetaConverter<Int> {
-            override val type: KType = typeOf<Int>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.NUMBER)
-            }
-
-            override fun metaToObjectOrNull(meta: Meta): Int? = meta.int
-            override fun objectToMeta(obj: Int): Meta = Meta(obj.asValue())
-        }
-
-        public val long: MetaConverter<Long> = object : MetaConverter<Long> {
-            override val type: KType = typeOf<Long>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.NUMBER)
-            }
-
-            override fun metaToObjectOrNull(meta: Meta): Long? = meta.long
-            override fun objectToMeta(obj: Long): Meta = Meta(obj.asValue())
-        }
-
-        public inline fun <reified E : Enum<E>> enum(): MetaConverter<E> = object : MetaConverter<E> {
-            override val type: KType = typeOf<E>()
-
-            override val descriptor: MetaDescriptor = MetaDescriptor {
-                valueType(ValueType.STRING)
-                allowedValues(enumValues<E>())
-            }
-
-            @Suppress("USELESS_CAST")
-            override fun metaToObjectOrNull(meta: Meta): E = meta.enum<E>() as? E ?: error("The Item is not a Enum")
-
-            override fun objectToMeta(obj: E): Meta = Meta(obj.asValue())
-        }
-
-        public fun <T> valueList(
-            writer: (T) -> Value = { Value.of(it) },
-            reader: (Value) -> T,
-        ): MetaConverter<List<T>> =
-            object : MetaConverter<List<T>> {
-                override val type: KType = typeOf<List<T>>()
-
-                override val descriptor: MetaDescriptor = MetaDescriptor {
-                    valueType(ValueType.LIST)
-                }
-
-                override fun metaToObjectOrNull(meta: Meta): List<T>? = meta.value?.list?.map(reader)
-
-                override fun objectToMeta(obj: List<T>): Meta = Meta(obj.map(writer).asValue())
-            }
-
-    }
-}
-
-public fun <T : Any> MetaConverter<T>.nullableMetaToObject(item: Meta?): T? = item?.let { metaToObject(it) }
-public fun <T : Any> MetaConverter<T>.nullableObjectToMeta(obj: T?): Meta? = obj?.let { objectToMeta(it) }
-
-public fun <T> MetaConverter<T>.valueToObject(value: Value): T? = metaToObject(Meta(value))

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/valueExtensions.kt

@@ -31,12 +31,5 @@ public inline fun <reified E : Enum<E>> Value.enum(): E = if (this is EnumValue<
 
 public val Value.stringList: List<String> get() = list.map { it.string }
 
-public val Value.doubleArray: DoubleArray
-    get() = if (this is DoubleArrayValue) {
-        value
-    } else {
-        DoubleArray(list.size) { list[it].double }
-    }
-
 
 public fun Value.toMeta(): Meta = Meta(this)

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/misc/DfType.kt

@@ -5,4 +5,4 @@ package space.kscience.dataforge.misc
  */
 @MustBeDocumented
 @Target(AnnotationTarget.CLASS)
-public annotation class DfId(val id: String)
+public annotation class DfType(val id: String)

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/misc/annotations.kt

@@ -18,4 +18,11 @@ public annotation class DFExperimental
  */
 @RequiresOptIn(level = RequiresOptIn.Level.WARNING)
 @Retention(AnnotationRetention.BINARY)
-public annotation class DFInternal
+public annotation class DFInternal
+
+/**
+ * Annotation marks methods that explicitly use KType without checking that it corresponds to the type parameter
+ */
+@RequiresOptIn(level = RequiresOptIn.Level.WARNING)
+@Retention(AnnotationRetention.BINARY)
+public annotation class UnsafeKType

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/misc/cast.kt

@@ -1,3 +0,0 @@
-package space.kscience.dataforge.misc
-
-public expect inline fun <T> Any?.unsafeCast(): T

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/names/Name.kt

@@ -16,12 +16,10 @@ public class Name(public val tokens: List<NameToken>) {
 
     override fun toString(): String = tokens.joinToString(separator = NAME_SEPARATOR) { it.toString() }
 
-    override fun equals(other: Any?): Boolean {
-        return when (other) {
-            is Name -> this.tokens == other.tokens
-            is NameToken -> this.length == 1 && this.tokens.first() == other
-            else -> false
-        }
+    override fun equals(other: Any?): Boolean = when (other) {
+        is Name -> this.tokens == other.tokens
+        is NameToken -> this.length == 1 && this.tokens.first() == other
+        else -> false
     }
 
     private val cachedHashCode = if (tokens.size == 1) {
@@ -115,6 +113,13 @@ public class Name(public val tokens: List<NameToken>) {
     }
 }
 
+/**
+ * Transform this [Name] to a string without escaping special characters in tokens.
+ *
+ * Parsing it back will produce a valid, but different name
+ */
+public fun Name.toStringUnescaped(): String = tokens.joinToString(separator = Name.NAME_SEPARATOR) { it.toStringUnescaped() }
+
 public operator fun Name.get(i: Int): NameToken = tokens[i]
 
 /**
@@ -216,9 +221,13 @@ public fun Name.endsWith(token: NameToken): Boolean = lastOrNull() == token
 public fun Name.startsWith(name: Name): Boolean =
     this.length >= name.length && (this == name || tokens.subList(0, name.length) == name.tokens)
 
+public fun Name.startsWith(name: String): Boolean = startsWith(name.parseAsName())
+
 public fun Name.endsWith(name: Name): Boolean =
     this.length >= name.length && (this == name || tokens.subList(length - name.length, length) == name.tokens)
 
+public fun Name.endsWith(name: String): Boolean = endsWith(name.parseAsName())
+
 /**
  * if [this] starts with given [head] name, returns the reminder of the name (could be empty). Otherwise, returns null
  */

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/names/NameIndexComparator.kt

@@ -0,0 +1,30 @@
+package space.kscience.dataforge.names
+
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.getIndexed
+
+
+/**
+ * A comparator for indices in a [Name]. If both indices are integers, compare them as integers.
+ * Null always stays "before" non-null index.
+ */
+public object NameIndexComparator : Comparator<String?> {
+    override fun compare(a: String?, b: String?): Int {
+        if (a == b) return 0
+        if (a == null) return 1
+        if (b == null) return -1
+        val aInt = a.toIntOrNull()
+        val bInt = b.toIntOrNull()
+        return if (aInt != null && bInt != null) {
+            aInt.compareTo(bInt)
+        } else {
+            a.compareTo(b)
+        }
+    }
+
+}
+
+public fun Meta.getIndexedList(name: Name): List<Meta> = getIndexed(name).entries.sortedWith(
+    //sort by index
+    compareBy(space.kscience.dataforge.names.NameIndexComparator) { it.key }
+).map{it.value}

dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/names/NameToken.kt

@@ -69,7 +69,7 @@ public class NameToken(public val body: String, public val index: String? = null
         public fun parse(string: String): NameToken {
             val body = string.substringBefore('[')
             val index = string.substringAfter('[', "")
-            if (index.isNotEmpty() && index.endsWith(']')) error("NameToken with index must end with ']'")
+            if (index.isNotEmpty() && !index.endsWith(']')) error("NameToken with index must end with ']'")
             return NameToken(body, index.removeSuffix("]"))
         }
     }

dataforge-meta/src/commonTest/kotlin/space/kscience/dataforge/meta/JsonMetaTest.kt

@@ -2,7 +2,7 @@ package space.kscience.dataforge.meta
 
 import kotlinx.serialization.json.*
 import space.kscience.dataforge.meta.descriptors.MetaDescriptor
-import space.kscience.dataforge.meta.descriptors.item
+import space.kscience.dataforge.meta.descriptors.node
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -32,7 +32,7 @@ class JsonMetaTest {
     }
 
     val descriptor = MetaDescriptor {
-        item("nodeArray") {
+        node("nodeArray") {
             indexKey = "index"
         }
     }

dataforge-meta/src/commonTest/kotlin/space/kscience/dataforge/meta/MetaDelegateTest.kt

@@ -20,7 +20,7 @@ class MetaDelegateTest {
         var myValue by string()
         var safeValue by double(2.2)
         var enumValue by enum(TestEnum.YES)
-        var inner by spec(InnerScheme)
+        var inner by scheme(InnerScheme)
 
         companion object : SchemeSpec<TestScheme>(::TestScheme)
     }

dataforge-meta/src/commonTest/kotlin/space/kscience/dataforge/meta/MetaTest.kt

@@ -61,4 +61,33 @@ class MetaTest {
         assertEquals(null, indexed["8"])
         assertEquals(12, indexed["12"].int)
     }
+
+    @Test
+    fun reset() {
+        val oldMeta = MutableMeta {
+            "a" put {
+                "value" put "aValue"
+            }
+            "b" put {
+                "value" put "bValue"
+            }
+            "c" put {
+                "value" put "cValue"
+            }
+        }
+        val newMeta = Meta {
+            "a" put {
+                "value" put "aValue"
+            }
+            "b" put {
+                "value" put "bValue"
+            }
+            "d" put {
+                "value" put "dValue"
+            }
+        }
+        oldMeta.reset(newMeta)
+        println(oldMeta)
+        assertEquals(setOf("a", "b", "d"), oldMeta.items.keys.map { it.toString() }.toSet())
+    }
 }

dataforge-meta/src/commonTest/kotlin/space/kscience/dataforge/meta/ObservableMetaTest.kt

@@ -0,0 +1,49 @@
+package space.kscience.dataforge.meta
+
+import space.kscience.dataforge.names.startsWith
+import kotlin.test.Ignore
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class ObservableMetaTest {
+
+    @Test
+    fun asObservable() {
+        val meta = MutableMeta {
+            "data" put {
+                "x" put ListValue(1, 2, 3)
+                "y" put ListValue(5, 6, 7)
+                "type" put "scatter"
+            }
+        }.asObservable()
+
+        assertEquals("scatter", meta["data.type"].string)
+    }
+
+    @Test
+    @Ignore
+    fun detachNode() {
+        val meta = MutableMeta {
+            "data" put {
+                "x" put ListValue(1, 2, 3)
+                "y" put ListValue(5, 6, 7)
+                "type" put "scatter"
+            }
+        }.asObservable()
+
+        var collector: Value? = null
+
+        meta.onChange(null) { name ->
+            if (name.startsWith("data")) {
+                collector = get("data.z")?.value
+            }
+        }
+
+        val data = meta["data"]!!
+
+        meta.remove("data")
+
+        data["z"] = ListValue(2, 5, 7)
+        assertEquals(null, collector)
+    }
+}

dataforge-meta/src/commonTest/kotlin/space/kscience/dataforge/meta/SchemeTest.kt

@@ -1,49 +0,0 @@
-package space.kscience.dataforge.meta
-
-import space.kscience.dataforge.misc.DFExperimental
-import kotlin.test.Test
-import kotlin.test.assertEquals
-import kotlin.test.assertNotNull
-
-@DFExperimental
-class SchemeTest {
-    @Test
-    fun testSchemeWrappingBeforeEdit() {
-        val config = MutableMeta()
-        val scheme = TestScheme.write(config)
-        scheme.a = 29
-        assertEquals(29, config["a"].int)
-    }
-
-    @Test
-    fun testSchemeWrappingAfterEdit() {
-        val scheme = TestScheme.empty()
-        scheme.a = 29
-        val config = MutableMeta()
-        scheme.retarget(config)
-        assertEquals(29, scheme.a)
-    }
-
-    @Test
-    fun testSchemeSubscription() {
-        val scheme = TestScheme.empty()
-        var flag: Int? = null
-        scheme.useProperty(TestScheme::a) { a ->
-            flag = a
-        }
-        scheme.a = 2
-        assertEquals(2, flag)
-    }
-
-    @Test
-    fun testListSubscription(){
-        val scheme = TestScheme.empty()
-        var value: Value? = null
-        scheme.v = ListValue(0.0,0.0,0.0)
-        scheme.useProperty(TestScheme::v){
-            value = it
-        }
-        scheme.v = ListValue(1.0, 2.0, 3.0)
-        assertNotNull(value)
-    }
-}

dataforge-meta/src/commonTest/kotlin/space/kscience/dataforge/meta/SpecificationTest.kt

@@ -1,7 +1,17 @@
 package space.kscience.dataforge.meta
 
+import space.kscience.dataforge.misc.DFExperimental
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+
+
+internal class SubScheme : Scheme() {
+
+    var subValue by string()
+
+    companion object : SchemeSpec<SubScheme>(::SubScheme)
+}
 
 internal class TestScheme : Scheme() {
     var list by numberList(1, 2, 3)
@@ -11,9 +21,23 @@ internal class TestScheme : Scheme() {
 
     var v by value()
 
+    var sub by scheme(SubScheme)
+
     companion object : SchemeSpec<TestScheme>(::TestScheme)
 }
 
+private class SchemeWithInit: Scheme(){
+    init {
+        set("initial", "initialValue")
+    }
+
+    var initial by string()
+
+    companion object: SchemeSpec<SchemeWithInit>(::SchemeWithInit)
+}
+
+
+
 class SpecificationTest {
 
 //    @Test
@@ -71,4 +95,64 @@ class SpecificationTest {
         assertEquals(22, config["child.a"].int)
         assertEquals("test", config["child.b"].string)
     }
+
+    @Test
+    fun testSchemeWrappingBeforeEdit() {
+        val config = MutableMeta()
+        val scheme = TestScheme.write(config)
+        scheme.a = 29
+        assertEquals(29, config["a"].int)
+    }
+
+    @OptIn(DFExperimental::class)
+    @Test
+    fun testSchemeWrappingAfterEdit() {
+        val scheme = TestScheme.empty()
+        scheme.a = 29
+        val config = MutableMeta()
+        scheme.retarget(config)
+        assertEquals(29, scheme.a)
+    }
+
+    @Test
+    fun testSchemeSubscription() {
+        val scheme = TestScheme.empty()
+        var flag: Int? = null
+        scheme.useProperty(TestScheme::a) { a ->
+            flag = a
+        }
+        scheme.a = 2
+        assertEquals(2, flag)
+    }
+
+    @Test
+    fun testListSubscription(){
+        val scheme = TestScheme.empty()
+        var value: Value? = null
+        scheme.v = ListValue(0.0,0.0,0.0)
+        scheme.useProperty(TestScheme::v){
+            value = it
+        }
+        scheme.v = ListValue(1.0, 2.0, 3.0)
+        assertNotNull(value)
+    }
+
+    @Test
+    fun testSubScheme(){
+        val scheme = TestScheme.empty()
+
+        scheme.sub.subValue = "aaa"
+
+        assertEquals("aaa",scheme.sub.subValue)
+    }
+
+
+    @Test
+    fun testSchemeWithInit(){
+        val scheme = SchemeWithInit()
+        assertEquals("initialValue", scheme.initial)
+        scheme.initial = "none"
+        assertEquals("none", scheme.initial)
+    }
+
 }

dataforge-meta/src/commonTest/kotlin/space/kscience/dataforge/meta/descriptors/DescriptorTest.kt

@@ -11,14 +11,14 @@ class DescriptorTest {
 
     val descriptor = MetaDescriptor {
         node("aNode") {
-            info = "A root demo node"
+            description = "A root demo node"
             value("b", ValueType.NUMBER) {
-                info = "b number value"
+                description = "b number value"
             }
             node("otherNode") {
                 value("otherValue", ValueType.BOOLEAN) {
                     default(false)
-                    info = "default value"
+                    description = "default value"
                 }
             }
         }