Simplify Scheme even more. Add serialization

build.gradle.kts

@@ -4,7 +4,7 @@ plugins {
 
 allprojects {
     group = "space.kscience"
-    version = "0.5.0"
+    version = "0.5.0-dev-2"
 }
 
 subprojects {

dataforge-meta/api/dataforge-meta.api

@@ -169,7 +169,9 @@ public final class space/kscience/dataforge/meta/MetaBase$Companion {
 }
 
 public final class space/kscience/dataforge/meta/MetaBuilder : space/kscience/dataforge/meta/AbstractMutableMeta {
+	public static final field Companion Lspace/kscience/dataforge/meta/MetaBuilder$Companion;
 	public fun <init> ()V
+	public synthetic fun <init> (ILjava/util/Map;Lkotlinx/serialization/internal/SerializationConstructorMarker;)V
 	public synthetic fun empty$dataforge_meta ()Lspace/kscience/dataforge/meta/MutableMeta;
 	public final fun put (Ljava/lang/String;Ljava/lang/Boolean;)V
 	public final fun put (Ljava/lang/String;Ljava/lang/Enum;)V
@@ -198,6 +200,22 @@ public final class space/kscience/dataforge/meta/MetaBuilder : space/kscience/da
 	public synthetic fun wrapNode (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/MutableMeta;
 }
 
+public final class space/kscience/dataforge/meta/MetaBuilder$$serializer : kotlinx/serialization/internal/GeneratedSerializer {
+	public static final field INSTANCE Lspace/kscience/dataforge/meta/MetaBuilder$$serializer;
+	public static final synthetic field descriptor Lkotlinx/serialization/descriptors/SerialDescriptor;
+	public fun childSerializers ()[Lkotlinx/serialization/KSerializer;
+	public synthetic fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Ljava/lang/Object;
+	public fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Lspace/kscience/dataforge/meta/MetaBuilder;
+	public fun getDescriptor ()Lkotlinx/serialization/descriptors/SerialDescriptor;
+	public synthetic fun serialize (Lkotlinx/serialization/encoding/Encoder;Ljava/lang/Object;)V
+	public fun serialize (Lkotlinx/serialization/encoding/Encoder;Lspace/kscience/dataforge/meta/MetaBuilder;)V
+	public fun typeParametersSerializers ()[Lkotlinx/serialization/KSerializer;
+}
+
+public final class space/kscience/dataforge/meta/MetaBuilder$Companion {
+	public final fun serializer ()Lkotlinx/serialization/KSerializer;
+}
+
 public final class space/kscience/dataforge/meta/MetaBuilderKt {
 	public static final fun Meta (Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/MetaBuilder;
 	public static final fun toMutableMeta (Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/meta/MetaBuilder;
@@ -364,6 +382,15 @@ public final class space/kscience/dataforge/meta/MutableItemProviderKt {
 	public static final fun withDefault (Lspace/kscience/dataforge/meta/MutableItemProvider;Lspace/kscience/dataforge/meta/ItemProvider;)Lspace/kscience/dataforge/meta/MutableItemProvider;
 }
 
+public final class space/kscience/dataforge/meta/MutableItemProviderSerializer : kotlinx/serialization/KSerializer {
+	public fun <init> ()V
+	public synthetic fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Ljava/lang/Object;
+	public fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Lspace/kscience/dataforge/meta/MutableItemProvider;
+	public fun getDescriptor ()Lkotlinx/serialization/descriptors/SerialDescriptor;
+	public synthetic fun serialize (Lkotlinx/serialization/encoding/Encoder;Ljava/lang/Object;)V
+	public fun serialize (Lkotlinx/serialization/encoding/Encoder;Lspace/kscience/dataforge/meta/MutableItemProvider;)V
+}
+
 public abstract interface class space/kscience/dataforge/meta/MutableMeta : space/kscience/dataforge/meta/MutableItemProvider, space/kscience/dataforge/meta/TypedMeta {
 	public abstract fun getItems ()Ljava/util/Map;
 }
@@ -410,10 +437,8 @@ public abstract interface class space/kscience/dataforge/meta/ReadOnlySpecificat
 
 public class space/kscience/dataforge/meta/Scheme : space/kscience/dataforge/meta/MetaRepr, space/kscience/dataforge/meta/ObservableItemProvider, space/kscience/dataforge/meta/descriptors/Described {
 	public fun <init> ()V
-	public fun <init> (Lspace/kscience/dataforge/meta/ObservableItemProvider;Lspace/kscience/dataforge/meta/descriptors/NodeDescriptor;Lspace/kscience/dataforge/meta/ItemProvider;)V
+	public fun <init> (Lspace/kscience/dataforge/meta/MutableItemProvider;Lspace/kscience/dataforge/meta/descriptors/NodeDescriptor;)V
-	public synthetic fun <init> (Lspace/kscience/dataforge/meta/ObservableItemProvider;Lspace/kscience/dataforge/meta/descriptors/NodeDescriptor;Lspace/kscience/dataforge/meta/ItemProvider;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public synthetic fun <init> (Lspace/kscience/dataforge/meta/MutableItemProvider;Lspace/kscience/dataforge/meta/descriptors/NodeDescriptor;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	protected fun getDefaultItem (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/TypedMetaItem;
-	public fun getDefaultLayer ()Lspace/kscience/dataforge/meta/Meta;
 	public synthetic fun getDescriptor ()Lspace/kscience/dataforge/meta/descriptors/ItemDescriptor;
 	public final fun getDescriptor ()Lspace/kscience/dataforge/meta/descriptors/NodeDescriptor;
 	public fun getItem (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/meta/TypedMetaItem;
@@ -430,8 +455,8 @@ public final class space/kscience/dataforge/meta/SchemeKt {
 	public static final fun invoke (Lspace/kscience/dataforge/meta/Scheme;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/meta/Scheme;
 	public static final fun isEmpty (Lspace/kscience/dataforge/meta/Scheme;)Z
 	public static final fun retarget (Lspace/kscience/dataforge/meta/Scheme;Lspace/kscience/dataforge/meta/MutableItemProvider;)Lspace/kscience/dataforge/meta/Scheme;
-	public static final fun wrap (Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/meta/MutableItemProvider;Lspace/kscience/dataforge/meta/ItemProvider;Lspace/kscience/dataforge/meta/descriptors/NodeDescriptor;)Lspace/kscience/dataforge/meta/Scheme;
+	public static final fun wrap (Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/meta/MutableItemProvider;Lspace/kscience/dataforge/meta/ItemProvider;)Lspace/kscience/dataforge/meta/Scheme;
-	public static synthetic fun wrap$default (Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/meta/MutableItemProvider;Lspace/kscience/dataforge/meta/ItemProvider;Lspace/kscience/dataforge/meta/descriptors/NodeDescriptor;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/Scheme;
+	public static synthetic fun wrap$default (Lspace/kscience/dataforge/meta/Specification;Lspace/kscience/dataforge/meta/MutableItemProvider;Lspace/kscience/dataforge/meta/ItemProvider;ILjava/lang/Object;)Lspace/kscience/dataforge/meta/Scheme;
 }
 
 public class space/kscience/dataforge/meta/SchemeSpec : space/kscience/dataforge/meta/Specification, space/kscience/dataforge/meta/descriptors/Described {

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

@@ -1,5 +1,6 @@
 package space.kscience.dataforge.meta
 
+import kotlinx.serialization.Serializable
 import space.kscience.dataforge.misc.DFBuilder
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.NameToken
@@ -13,6 +14,7 @@ import kotlin.jvm.JvmName
  * DSL builder for meta. Is not intended to store mutable state
  */
 @DFBuilder
+@Serializable
 public class MetaBuilder : AbstractMutableMeta<MetaBuilder>() {
     override val children: MutableMap<NameToken, TypedMetaItem<MetaBuilder>> = LinkedHashMap()
 

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

@@ -1,12 +1,35 @@
 package space.kscience.dataforge.meta
 
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 import space.kscience.dataforge.names.*
 import space.kscience.dataforge.values.Value
 
+@Serializable(MutableItemProviderSerializer::class)
 public interface MutableItemProvider : ItemProvider {
     public fun setItem(name: Name, item: MetaItem?)
 }
 
+/**
+ * A serializer form [MutableItemProvider]
+ */
+public class MutableItemProviderSerializer : KSerializer<MutableItemProvider> {
+    override val descriptor: SerialDescriptor = MetaSerializer.descriptor
+
+
+    override fun deserialize(decoder: Decoder): MutableItemProvider {
+        val meta = decoder.decodeSerializableValue(MetaSerializer)
+        return (meta as? MetaBuilder) ?: meta.toMutableMeta()
+    }
+
+    override fun serialize(encoder: Encoder, value: MutableItemProvider) {
+        encoder.encodeSerializableValue(MetaSerializer, value.rootItem?.node ?: Meta.EMPTY)
+    }
+}
+
 public operator fun MutableItemProvider.set(name: Name, item: MetaItem?): Unit = setItem(name, item)
 
 public operator fun MutableItemProvider.set(name: Name, value: Value?): Unit = set(name, value?.asMetaItem())

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

@@ -5,8 +5,6 @@ import space.kscience.dataforge.meta.descriptors.NodeDescriptor
 import space.kscience.dataforge.meta.descriptors.get
 import space.kscience.dataforge.meta.descriptors.validateItem
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.NameToken
-import space.kscience.dataforge.names.asName
 import kotlin.jvm.Synchronized
 
 /**
@@ -15,8 +13,7 @@ import kotlin.jvm.Synchronized
  */
 public open class Scheme(
     private var items: ObservableItemProvider = ObservableMeta(),
-    final override var descriptor: NodeDescriptor? = null,
+    final override var descriptor: NodeDescriptor? = null
-    private var default: ItemProvider? = null
 ) : Described, MetaRepr, ObservableItemProvider {
 
     /**
@@ -38,24 +35,15 @@ public open class Scheme(
 
     internal fun wrap(
         items: MutableItemProvider,
-        default: ItemProvider? = null,
+        preserveDefault: Boolean = false
-        descriptor: NodeDescriptor? = null,
     ) {
-        //use properties in the init block as default
+        this.items = if (preserveDefault) items.withDefault(this.items).asObservable() else items.asObservable()
-        this.default = this.items.withDefault(default)
-        //reset values, defaults are already saved
-        this.items = items.asObservable()
-        this.descriptor = descriptor
-    }
-
-    protected open fun getDefaultItem(name: Name): MetaItem? {
-        return default?.get(name) ?: descriptor?.get(name)?.defaultValue
     }
 
     /**
      * Get a property with default
      */
-    override fun getItem(name: Name): MetaItem? = items[name] ?: getDefaultItem(name)
+    override fun getItem(name: Name): MetaItem? = items[name] ?: descriptor?.get(name)?.defaultValue
 
     /**
      * Check if property with given [name] could be assigned to [item]
@@ -70,34 +58,16 @@ public open class Scheme(
      */
     override fun setItem(name: Name, item: MetaItem?) {
         val oldItem = items[name]
+        if (oldItem != item) {
             if (validateItem(name, item)) {
                 items[name] = item
             } else {
                 error("Validation failed for property $name with value $item")
             }
         }
-
-
-    /**
-     * Provide a default layer which returns items from [default] and falls back to descriptor
-     * values if default value is unavailable.
-     * Values from [default] completely replace
-     */
-    public open val defaultLayer: Meta
-        get() = object : MetaBase() {
-            override val items: Map<NameToken, MetaItem> = buildMap {
-                descriptor?.items?.forEach { (key, itemDescriptor) ->
-                    val token = NameToken(key)
-                    val name = token.asName()
-                    val item = default?.get(name) ?: itemDescriptor.defaultValue
-                    if (item != null) {
-                        put(token, item)
-                    }
-                }
-            }
     }
 
-    override fun toMeta(): Laminate = Laminate(items.rootNode, defaultLayer)
+    override fun toMeta(): Laminate = Laminate(items.rootNode, descriptor?.defaultMeta)
 }
 
 /**
@@ -105,23 +75,13 @@ public open class Scheme(
  */
 public fun Scheme.isEmpty(): Boolean = rootItem == null
 
-/**
- * Create a new empty [Scheme] object (including defaults) and inflate it around existing [MutableItemProvider].
- * Items already present in the scheme are used as defaults.
- */
-public fun <T : Scheme, S : Specification<T>> S.wrap(
-    items: MutableItemProvider,
-    default: ItemProvider? = null,
-    descriptor: NodeDescriptor? = null,
-): T = empty().apply {
-    wrap(items, default, descriptor)
-}
-
 /**
  * Relocate scheme target onto given [MutableItemProvider]. Old provider does not get updates anymore.
  * Current state of the scheme used as a default.
  */
-public fun <T : Scheme> T.retarget(provider: MutableItemProvider): T = apply { wrap(provider) }
+public fun <T : Scheme> T.retarget(provider: MutableItemProvider): T = apply {
+    wrap(provider, true)
+}
 
 /**
  * A shortcut to edit a [Scheme] object in-place
@@ -135,16 +95,22 @@ public open class SchemeSpec<out T : Scheme>(
     private val builder: () -> T,
 ) : Specification<T>, Described {
 
-    override fun empty(): T = builder()
+    override fun read(items: ItemProvider): T = empty().also {
+        it.wrap(ObservableMeta().withDefault(items))
+    }
 
-    override fun read(items: ItemProvider): T = wrap(ObservableMeta(), items, descriptor)
+    override fun write(target: MutableItemProvider): T = empty().also {
-
+        it.wrap(target)
-    override fun write(target: MutableItemProvider, defaultProvider: ItemProvider): T =
+    }
-        wrap(target, defaultProvider, descriptor)
 
     //TODO Generate descriptor from Scheme class
     override val descriptor: NodeDescriptor? get() = null
 
+    override fun empty(): T = builder().also {
+        it.descriptor = descriptor
+    }
+
     @Suppress("OVERRIDE_BY_INLINE")
     final override inline operator fun invoke(action: T.() -> Unit): T = empty().apply(action)
+
 }

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

@@ -35,7 +35,7 @@ public interface Specification<out T : MutableItemProvider> : ReadOnlySpecificat
     /**
      * Wrap [MutableItemProvider], using it as inner storage (changes to [Specification] are reflected on [MutableItemProvider]
      */
-    public fun write(target: MutableItemProvider, defaultProvider: ItemProvider = ItemProvider.EMPTY): T
+    public fun write(target: MutableItemProvider): T
 }
 
 /**

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

@@ -7,15 +7,15 @@ import kotlin.test.assertEquals
 @DFExperimental
 class SchemeTest {
     @Test
-    fun testSchemeWrappingBeforeEdit(){
+    fun testSchemeWrappingBeforeEdit() {
         val config = MetaBuilder()
-        val scheme = TestScheme.wrap(config)
+        val scheme = TestScheme.write(config)
         scheme.a = 29
         assertEquals(29, config["a"].int)
     }
 
     @Test
-    fun testSchemeWrappingAfterEdit(){
+    fun testSchemeWrappingAfterEdit() {
         val scheme = TestScheme.empty()
         scheme.a = 29
         val config = MetaBuilder()
@@ -24,10 +24,10 @@ class SchemeTest {
     }
 
     @Test
-    fun testSchemeSubscription(){
+    fun testSchemeSubscription() {
         val scheme = TestScheme.empty()
         var flag: Int? = null
-        scheme.useProperty(TestScheme::a){a->
+        scheme.useProperty(TestScheme::a) { a ->
             flag = a
         }
         scheme.a = 2

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

@@ -9,16 +9,7 @@ internal class TestScheme : Scheme() {
     var a by int()
     var b by string()
 
-    companion object : Specification<TestScheme> {
+    companion object : SchemeSpec<TestScheme>(::TestScheme)
-        override fun empty(): TestScheme = TestScheme()
-
-        override fun read(items: ItemProvider): TestScheme =
-            wrap(MetaBuilder(), items)
-
-        override fun write(target: MutableItemProvider, defaultProvider: ItemProvider): TestScheme =
-            wrap(target, defaultProvider)
-
-    }
 }
 
 class SpecificationTest {