Merge pull request '0.7.0' (!79) from dev into master

Reviewed-on: #79

.github/workflows/build.yml

@@ -1,6 +1,9 @@
 name: Gradle build
 
-on: [ push ]
+on:
+  push:
+    branches: [ dev, master ]
+  pull_request:
 
 jobs:
   build:
@@ -8,20 +11,22 @@ jobs:
       matrix:
         os: [ macOS-latest, windows-latest ]
     runs-on: ${{matrix.os}}
+    timeout-minutes: 40
     steps:
       - name: Checkout the repo
         uses: actions/checkout@v2
       - name: Set up JDK 11
-        uses: actions/setup-java@v1
+        uses: DeLaGuardo/setup-graalvm@4.0
         with:
-          java-version: 11
-      - name: Add msys to path
-        if: matrix.os == 'windows-latest'
-        run: SETX PATH "%PATH%;C:\msys64\mingw64\bin"
+          graalvm: 21.2.0
+          java: java11
+          arch: amd64
       - name: Cache gradle
         uses: actions/cache@v2
         with:
-          path: ~/.gradle/caches
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
           key: ${{ runner.os }}-gradle-${{ hashFiles('*.gradle.kts') }}
           restore-keys: |
             ${{ runner.os }}-gradle-
@@ -33,4 +38,4 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-gradle-
       - name: Build
-        run: ./gradlew build --no-daemon --stacktrace
+        run: ./gradlew build --build-cache --no-daemon --stacktrace

.github/workflows/pages.yml

@@ -0,0 +1,31 @@
+name: Dokka publication
+
+on:
+  workflow_dispatch:
+  release:
+    types: [ created ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 40
+    steps:
+      - uses: actions/checkout@v3.0.0
+      - uses: actions/setup-java@v3.0.0
+        with:
+          java-version: 11
+          distribution: liberica
+      - name: Cache konan
+        uses: actions/cache@v3.0.1
+        with:
+          path: ~/.konan
+          key: ${{ runner.os }}-gradle-${{ hashFiles('*.gradle.kts') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+      - uses: gradle/gradle-build-action@v2.4.2
+        with:
+          arguments: dokkaHtmlMultiModule --no-parallel
+      - uses: JamesIves/github-pages-deploy-action@v4.3.0
+        with:
+          branch: gh-pages
+          folder: build/dokka/htmlMultiModule

.github/workflows/publish.yml

@@ -3,8 +3,7 @@ name: Gradle publish
 on:
   workflow_dispatch:
   release:
-    types:
-      - created
+    types: [ created ]
 
 jobs:
   publish:
@@ -12,27 +11,16 @@ jobs:
       name: publish
     strategy:
       matrix:
-        os: [macOS-latest, windows-latest]
+        os: [ macOS-latest, windows-latest ]
     runs-on: ${{matrix.os}}
     steps:
-      - name: Checkout the repo
-        uses: actions/checkout@v2
-      - name: Set up JDK 11
-        uses: actions/setup-java@v1
+      - uses: actions/checkout@v3.0.0
+      - uses: actions/setup-java@v3.10.0
         with:
           java-version: 11
-      - name: Add msys to path
-        if: matrix.os == 'windows-latest'
-        run: SETX PATH "%PATH%;C:\msys64\mingw64\bin"
-      - name: Cache gradle
-        uses: actions/cache@v2
-        with:
-          path: ~/.gradle/caches
-          key: ${{ runner.os }}-gradle-${{ hashFiles('*.gradle.kts') }}
-          restore-keys: |
-            ${{ runner.os }}-gradle-
+          distribution: liberica
       - name: Cache konan
-        uses: actions/cache@v2
+        uses: actions/cache@v3.0.1
         with:
           path: ~/.konan
           key: ${{ runner.os }}-gradle-${{ hashFiles('*.gradle.kts') }}
@@ -40,20 +28,23 @@ jobs:
             ${{ runner.os }}-gradle-
       - name: Publish Windows Artifacts
         if: matrix.os == 'windows-latest'
-        run: >
-          ./gradlew release --no-daemon
-          -Ppublishing.enabled=true
-          -Ppublishing.github.user=${{ secrets.PUBLISHING_GITHUB_USER }}
-          -Ppublishing.github.token=${{ secrets.PUBLISHING_GITHUB_TOKEN }}
-          -Ppublishing.space.user=${{ secrets.PUBLISHING_SPACE_USER }}
-          -Ppublishing.space.token=${{ secrets.PUBLISHING_SPACE_TOKEN }}
+        uses: gradle/gradle-build-action@v2.4.2
+        with:
+          arguments: |
+            publishAllPublicationsToSpaceRepository
+            -Ppublishing.targets=all
+            -Ppublishing.space.user=${{ secrets.SPACE_APP_ID }}
+            -Ppublishing.space.token=${{ secrets.SPACE_APP_SECRET }}
       - name: Publish Mac Artifacts
         if: matrix.os == 'macOS-latest'
-        run: >
-          ./gradlew release --no-daemon
-          -Ppublishing.enabled=true
-          -Ppublishing.platform=macosX64
-          -Ppublishing.github.user=${{ secrets.PUBLISHING_GITHUB_USER }}
-          -Ppublishing.github.token=${{ secrets.PUBLISHING_GITHUB_TOKEN }}
-          -Ppublishing.space.user=${{ secrets.PUBLISHING_SPACE_USER }}
-          -Ppublishing.space.token=${{ secrets.PUBLISHING_SPACE_TOKEN }}
+        uses: gradle/gradle-build-action@v2.4.2
+        with:
+          arguments: |
+            publishMacosX64PublicationToSpaceRepository
+            publishMacosArm64PublicationToSpaceRepository
+            publishIosX64PublicationToSpaceRepository
+            publishIosArm64PublicationToSpaceRepository
+            publishIosSimulatorArm64PublicationToSpaceRepository
+            -Ppublishing.targets=all
+            -Ppublishing.space.user=${{ secrets.SPACE_APP_ID }}
+            -Ppublishing.space.token=${{ secrets.SPACE_APP_SECRET }}

CHANGELOG.md

@@ -1,26 +1,173 @@
 # Changelog
 
-## [Unreleased]
+## Unreleased
+
 ### Added
-- LogManager plugin
-- dataforge-context API dependency on SLF4j
 
 ### Changed
-- Kotlin-logging moved from common to JVM and JS. Replaced by console for native.
-- Package changed to `space.kscience`
 
 ### Deprecated
 
 ### Removed
-- Common dependency on Kotlin-logging
-- Kotlinx-io fork dependency. Replaced by Ktor-io.
 
 ### Fixed
 
 ### Security
 
-## [0.3.0]
+## 0.7.0 - 2023-11-26
+
 ### Added
+
+- Obligatory `type: KType` and `descriptor` property for `MetaConverters`
+- Added separate `Meta`, `SealedMeta` and `ObservableMutableMeta` builders.
+
+### Changed
+
+- Meta converter `metaToObject` returns a non-nullable type. Additional method `metaToObjectOrNull` for nullable return.
+- Kotlin 1.9.20.
+- Migrated from ktor-io to kotlinx-io.
+- `MutableMeta` builder now returns a simplified version of meta that does not hold listeners.
+- More concise names for read/write methods in IO.
+- Remove unnecessary confusion with `get`/`getMeta` by removing `getMeta` from the interface.
+
+### Deprecated
+
+- `String.parseValue` is replaced with `Value.parse`
+
+### Fixed
+
+- Memory leak in SealedMeta builder
+
+## 0.6.2 - 2023-07-29
+
+### Changed
+
+- Meta to Json serializer now serializes a single item with index as an array. It is important for plotly integration.
+- Meta to Json serializes Meta without children a value as literal or array instead of an object with `@value` field.
+
+## 0.6.1 - 2023-03-31
+
+### Added
+
+- File cache for workspace
+- Smart task metadata transformation for workspace
+- Add `readOnly` property to descriptors
+- Add `specOrNull` delegate to meta and Scheme
+- Suspended read methods to the `Binary`
+- Synchronously accessed `meta` to all `DataSet`s
+- More fine-grained types in Action builders.
+
+### Changed
+
+- `Name::replaceLast` API
+- `PluginFactory` no longer requires plugin class
+- Collection<Named> toMap -> associateByName
+- Simplified `DFTL` envelope format. Closing symbols are unnecessary. Properties are discontinued.
+- Meta `get` method allows nullable receiver
+- `withDefault` functions do not add new keys to meta children and are consistent.
+- `dataforge.meta.values` package is merged into `dataforge.meta` for better star imports
+- Kotlin 1.8.20
+- `Factory` is now `fun interface` and uses `build` instead of `invoke`. `invoke moved to an extension.
+- KTor 2.0
+- DataTree `items` call is blocking.
+- DataSet `getData` is no longer suspended and renamed to `get`
+- DataSet operates with sequences of data instead of flows
+- PartialEnvelope uses `Int` instead `UInt`.
+- `ActiveDataSet` renamed to `DataSource`
+- `selectOne`->`getByType`
+- Data traversal in `DataSet` is done via iterator
+- Remove all unnecessary properties for `IOFormat`
+- Separate interfaces for `IOReader` and `IOWriter`
+
+### Deprecated
+
+- Context.fetch -> Context.request
+
+### Fixed
+
+- `readDataDirectory` does not split names with dots
+- Front matter reader does not crash on non-UTF files
+- Meta file name in readMeta from directory
+- Tagless and FrontMatter envelope partial readers fix.
+
+## 0.5.2
+
+### Added
+
+- Yaml plugin
+- Partial fix to #53
+
+### Fixed
+
+- MutableMetaImpl attachment and checks
+- Listeners in observable meta are replaced by lists
+- JS number comparison bug.
+
+## 0.5.0
+
+### Added
+
+- Experimental `listOfSpec` delegate.
+
+### Changed
+
+- **API breaking** Config is deprecated, use `ObservableMeta` instead.
+- **API breaking** Descriptor no has a member property `defaultValue` instead of `defaultItem()` extension. It caches default value state on the first call. It is done because computing default on each call is too expensive.
+- Kotlin 1.5.10
+- Build tools 0.10.0
+- Relaxed type restriction on `MetaConverter`. Now nullables are available.
+- **Huge API-breaking refactoring of Meta**. Meta now can have both value and children. There is only one kind of descriptor now.
+- **API breaking** `String.toName()` is replaced by `Name.parse()`
+- **API breaking** Configurable`config` changed to `meta`
+
+### Removed
+
+- `Config`
+- Public PluginManager mutability
+- Tables and tables-exposed moved to the separate project `tables.kt`
+- BinaryMetaFormat. Use CBOR encoding instead
+
+### Fixed
+
+- Proper json array index treatment.
+- Proper json index for single-value array.
+
+## 0.4.0
+
+### Added
+
+- LogManager plugin
+- dataforge-context API dependency on SLF4j
+- Context `withEnv` and `fetch` methods to manipulate plugins without changing plugins after creation.
+- Split `ItemDescriptor` into builder and read-only part
+
+### Changed
+
+- Kotlin-logging moved from common to JVM and JS. Replaced by console for native.
+- Package changed to `space.kscience`
+- Scheme made observable
+- Global context is a variable (the singleton is hidden and will be deprecated in future)
+- Kotlin 1.5
+- Added blank builders for children context.
+- Refactor loggers
+
+### Deprecated
+
+- Direct use of PluginManager
+
+### Removed
+
+- Common dependency on Kotlin-logging
+- Kotlinx-io fork dependency. Replaced by Ktor-io.
+
+### Fixed
+
+- Scheme properties properly handle children property change.
+
+## 0.3.0
+
+### Added
+
 - Yaml meta format based on yaml.kt
 - `Path` builders
 - Special ValueType for lists
@@ -28,6 +175,7 @@
 - Multiplatform yaml meta
 
 ### Changed
+
 - `ListValue` and `DoubleArrayValue` implement `Iterable`.
 - Changed the logic of `Value::isList` to check for type instead of size
 - `Meta{}` builder made inline
@@ -41,18 +189,10 @@
 - \[Major breaking change\] Full refactor of DataTree/DataSource
 - \[Major Breaking change\] Replace KClass with KType in data. Remove direct access to constructors with types.
 
-### Deprecated
-
-### Removed
-
-### Fixed
-
-### Security
-
-## [0.2.0]
-### Added
+## 0.2.0
 
 ### Changed
+
 - Context content resolution refactor
 - Kotlin 1.4.10 (build tools 0.6.0)
 - Empty query in Name is null instead of ""
@@ -62,15 +202,16 @@
 - Configurable is no longer MutableItemProvider. All functionality moved to Scheme.
 
 ### Deprecated
+
 - Context activation API
 - TextRenderer
 
 ### Removed
+
 - Functional server prototype
 - `dataforge-output` module
 
 ### Fixed
+
 - Global context CoroutineScope resolution
 - Library mode compliance
-
-### Security

LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
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+
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README.md

@@ -3,53 +3,36 @@
 
 ![Gradle build](https://github.com/mipt-npm/dataforge-core/workflows/Gradle%20build/badge.svg)
 
-<hr/>
 
-* ### [dataforge-context](dataforge-context)
-> 
+### [dataforge-context](dataforge-context)
+> Context and provider definitions
 >
 > **Maturity**: DEVELOPMENT
-<hr/>
 
-* ### [dataforge-data](dataforge-data)
-> 
+### [dataforge-data](dataforge-data)
 >
 > **Maturity**: EXPERIMENTAL
-<hr/>
 
-* ### [dataforge-io](dataforge-io)
-> 
+### [dataforge-io](dataforge-io)
+> IO module
 >
-> **Maturity**: PROTOTYPE
-<hr/>
+> **Maturity**: EXPERIMENTAL
 
-* ### [dataforge-meta](dataforge-meta)
-> 
+### [dataforge-meta](dataforge-meta)
+> Meta definition and basic operations on meta
 >
 > **Maturity**: DEVELOPMENT
-<hr/>
 
-* ### [dataforge-scripting](dataforge-scripting)
-> 
+### [dataforge-scripting](dataforge-scripting)
 >
 > **Maturity**: PROTOTYPE
-<hr/>
 
-* ### [dataforge-tables](dataforge-tables)
-> 
->
-> **Maturity**: PROTOTYPE
-<hr/>
-
-* ### [dataforge-workspace](dataforge-workspace)
-> 
+### [dataforge-workspace](dataforge-workspace)
 >
 > **Maturity**: EXPERIMENTAL
-<hr/>
 
-* ### [dataforge-io-yaml](dataforge-io/dataforge-io-yaml)
+### [dataforge-io/dataforge-io-yaml](dataforge-io/dataforge-io-yaml)
 > YAML meta converters and Front Matter envelope format
 >
 > **Maturity**: PROTOTYPE
-<hr/>
 

build.gradle.kts

@@ -1,17 +1,23 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import space.kscience.gradle.useApache2Licence
+import space.kscience.gradle.useSPCTeam
+
 plugins {
-    id("ru.mipt.npm.gradle.project")
+    id("space.kscience.gradle.project")
 }
 
 allprojects {
     group = "space.kscience"
-    version = "0.4.0-dev-2"
+    version = "0.7.0"
 }
 
 subprojects {
     apply(plugin = "maven-publish")
-    repositories {
-        maven("https://dl.bintray.com/mipt-npm/kscience")
-        maven("https://dl.bintray.com/mipt-npm/dev")
+
+    tasks.withType<KotlinCompile> {
+        kotlinOptions {
+            freeCompilerArgs = freeCompilerArgs + "-Xcontext-receivers"
+        }
     }
 }
 
@@ -20,8 +26,11 @@ readme {
 }
 
 ksciencePublish {
-    github("dataforge-core")
-    space("https://maven.pkg.jetbrains.space/mipt-npm/p/sci/maven")
+    pom("https://github.com/SciProgCentre/kmath") {
+        useApache2Licence()
+        useSPCTeam()
+    }
+    repository("spc","https://maven.sciprog.center/kscience")
     sonatype()
 }
 

dataforge-context/README.md

@@ -0,0 +1,23 @@
+# Module dataforge-context
+
+Context and provider definitions
+
+## Usage
+
+## Artifact:
+
+The Maven coordinates of this project are `space.kscience:dataforge-context:0.7.0`.
+
+**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")
+}
+```

dataforge-context/api/dataforge-context.api

@@ -3,21 +3,17 @@ public abstract class space/kscience/dataforge/context/AbstractPlugin : space/ks
 	public fun <init> (Lspace/kscience/dataforge/meta/Meta;)V
 	public synthetic fun <init> (Lspace/kscience/dataforge/meta/Meta;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public fun attach (Lspace/kscience/dataforge/context/Context;)V
-	public fun content (Ljava/lang/String;)Ljava/util/Map;
-	public final fun dependsOn ()Ljava/util/Map;
+	public fun dependsOn ()Ljava/util/Map;
 	public fun detach ()V
 	public fun getContext ()Lspace/kscience/dataforge/context/Context;
-	public fun getDefaultChainTarget ()Ljava/lang/String;
-	public fun getDefaultTarget ()Ljava/lang/String;
 	public fun getMeta ()Lspace/kscience/dataforge/meta/Meta;
-	public fun getName ()Lspace/kscience/dataforge/names/Name;
-	protected final fun require (Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;)Lkotlin/properties/ReadOnlyProperty;
-	public static synthetic fun require$default (Lspace/kscience/dataforge/context/AbstractPlugin;Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
-	public fun toMeta ()Lspace/kscience/dataforge/meta/Meta;
+	public fun isAttached ()Z
+	protected final fun require (Lspace/kscience/dataforge/context/PluginFactory;Lkotlin/reflect/KClass;Lspace/kscience/dataforge/meta/Meta;)Lkotlin/properties/ReadOnlyProperty;
+	public static synthetic fun require$default (Lspace/kscience/dataforge/context/AbstractPlugin;Lspace/kscience/dataforge/context/PluginFactory;Lkotlin/reflect/KClass;Lspace/kscience/dataforge/meta/Meta;ILjava/lang/Object;)Lkotlin/properties/ReadOnlyProperty;
 }
 
 public final class space/kscience/dataforge/context/AbstractPluginKt {
-	public static final fun toMap (Ljava/util/Collection;)Ljava/util/Map;
+	public static final fun associateByName (Ljava/util/Collection;)Ljava/util/Map;
 }
 
 public final class space/kscience/dataforge/context/ClassLoaderPlugin : space/kscience/dataforge/context/AbstractPlugin {
@@ -38,15 +34,17 @@ public final class space/kscience/dataforge/context/ClassLoaderPluginKt {
 public class space/kscience/dataforge/context/Context : kotlinx/coroutines/CoroutineScope, space/kscience/dataforge/meta/MetaRepr, space/kscience/dataforge/misc/Named, space/kscience/dataforge/provider/Provider {
 	public static final field Companion Lspace/kscience/dataforge/context/Context$Companion;
 	public static final field PROPERTY_TARGET Ljava/lang/String;
+	public final fun buildContext (Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/Context;
+	public static synthetic fun buildContext$default (Lspace/kscience/dataforge/context/Context;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/context/Context;
 	public fun close ()V
 	public fun content (Ljava/lang/String;)Ljava/util/Map;
 	public final fun content (Ljava/lang/String;Z)Ljava/util/Map;
 	public fun getCoroutineContext ()Lkotlin/coroutines/CoroutineContext;
-	public fun getDefaultChainTarget ()Ljava/lang/String;
 	public fun getDefaultTarget ()Ljava/lang/String;
 	public final fun getName ()Lspace/kscience/dataforge/names/Name;
 	public final fun getParent ()Lspace/kscience/dataforge/context/Context;
 	public final fun getPlugins ()Lspace/kscience/dataforge/context/PluginManager;
+	public final fun getProperties ()Lspace/kscience/dataforge/meta/Laminate;
 	public fun toMeta ()Lspace/kscience/dataforge/meta/Meta;
 }
 
@@ -58,51 +56,62 @@ public abstract interface class space/kscience/dataforge/context/ContextAware {
 }
 
 public final class space/kscience/dataforge/context/ContextBuilder {
-	public fun <init> ()V
-	public fun <init> (Lspace/kscience/dataforge/context/Context;Ljava/lang/String;)V
-	public synthetic fun <init> (Lspace/kscience/dataforge/context/Context;Ljava/lang/String;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun build ()Lspace/kscience/dataforge/context/Context;
-	public final fun getName ()Ljava/lang/String;
+	public final fun getName ()Lspace/kscience/dataforge/names/Name;
 	public final fun plugin (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlin/jvm/functions/Function1;)V
+	public final fun plugin (Lspace/kscience/dataforge/context/Plugin;)V
 	public final fun plugin (Lspace/kscience/dataforge/context/PluginFactory;Lkotlin/jvm/functions/Function1;)V
+	public final fun plugin (Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;)V
 	public final fun plugin (Lspace/kscience/dataforge/context/PluginTag;Lkotlin/jvm/functions/Function1;)V
 	public static synthetic fun plugin$default (Lspace/kscience/dataforge/context/ContextBuilder;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 	public static synthetic fun plugin$default (Lspace/kscience/dataforge/context/ContextBuilder;Lspace/kscience/dataforge/context/PluginFactory;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 	public static synthetic fun plugin$default (Lspace/kscience/dataforge/context/ContextBuilder;Lspace/kscience/dataforge/context/PluginTag;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 	public final fun properties (Lkotlin/jvm/functions/Function1;)V
-	public final fun setName (Ljava/lang/String;)V
 }
 
-public final class space/kscience/dataforge/context/ContextKt {
-	public static final fun Context (Ljava/lang/String;Lspace/kscience/dataforge/context/Context;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/Context;
-	public static synthetic fun Context$default (Ljava/lang/String;Lspace/kscience/dataforge/context/Context;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/context/Context;
+public final class space/kscience/dataforge/context/ContextBuilderKt {
+}
+
+public final class space/kscience/dataforge/context/DefaultLogManager : space/kscience/dataforge/context/AbstractPlugin, space/kscience/dataforge/context/LogManager {
+	public static final field Companion Lspace/kscience/dataforge/context/DefaultLogManager$Companion;
+	public fun <init> ()V
+	public fun getDefaultLogger ()Lspace/kscience/dataforge/context/Logger;
+	public fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
+	public fun logger (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/context/Logger;
+}
+
+public final class space/kscience/dataforge/context/DefaultLogManager$Companion : space/kscience/dataforge/context/PluginFactory {
+	public synthetic fun build (Lspace/kscience/dataforge/context/Context;Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+	public fun build (Lspace/kscience/dataforge/context/Context;Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/context/DefaultLogManager;
+	public fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
 }
 
 public abstract interface class space/kscience/dataforge/context/Factory {
-	public abstract fun invoke (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/context/Context;)Ljava/lang/Object;
+	public abstract fun build (Lspace/kscience/dataforge/context/Context;Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
 }
 
-public final class space/kscience/dataforge/context/Factory$DefaultImpls {
+public final class space/kscience/dataforge/context/FactoryKt {
+	public static final fun invoke (Lspace/kscience/dataforge/context/Factory;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/context/Context;)Ljava/lang/Object;
 	public static synthetic fun invoke$default (Lspace/kscience/dataforge/context/Factory;Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/context/Context;ILjava/lang/Object;)Ljava/lang/Object;
 }
 
-public final class space/kscience/dataforge/context/Global : space/kscience/dataforge/context/Context {
-	public static final field INSTANCE Lspace/kscience/dataforge/context/Global;
-	public fun close ()V
-	public final fun context (Ljava/lang/String;Lspace/kscience/dataforge/context/Context;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/Context;
-	public static synthetic fun context$default (Lspace/kscience/dataforge/context/Global;Ljava/lang/String;Lspace/kscience/dataforge/context/Context;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/context/Context;
-	public final fun getContext (Ljava/lang/String;)Lspace/kscience/dataforge/context/Context;
-	public fun getCoroutineContext ()Lkotlin/coroutines/CoroutineContext;
-	public final fun getLogger ()Lspace/kscience/dataforge/context/LogManager;
+public final class space/kscience/dataforge/context/GlobalKt {
+	public static final fun Context (Ljava/lang/String;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/Context;
+	public static synthetic fun Context$default (Ljava/lang/String;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/context/Context;
+	public static final fun getGlobal ()Lspace/kscience/dataforge/context/Context;
 }
 
-public abstract interface class space/kscience/dataforge/context/LogManager : space/kscience/dataforge/context/Logable, space/kscience/dataforge/context/Plugin {
+public abstract interface class space/kscience/dataforge/context/LogManager : space/kscience/dataforge/context/Logger, space/kscience/dataforge/context/Plugin {
 	public static final field Companion Lspace/kscience/dataforge/context/LogManager$Companion;
 	public static final field DEBUG Ljava/lang/String;
 	public static final field ERROR Ljava/lang/String;
 	public static final field INFO Ljava/lang/String;
 	public static final field TRACE Ljava/lang/String;
 	public static final field WARNING Ljava/lang/String;
+	public abstract fun getDefaultLogger ()Lspace/kscience/dataforge/context/Logger;
+	public fun log (Ljava/lang/String;Lkotlin/jvm/functions/Function0;)V
+	public fun log (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;Lkotlin/jvm/functions/Function0;)V
+	public abstract fun logger (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/context/Logger;
 }
 
 public final class space/kscience/dataforge/context/LogManager$Companion {
@@ -113,33 +122,19 @@ public final class space/kscience/dataforge/context/LogManager$Companion {
 	public static final field WARNING Ljava/lang/String;
 }
 
-public final class space/kscience/dataforge/context/LogManager$DefaultImpls {
-	public static fun content (Lspace/kscience/dataforge/context/LogManager;Ljava/lang/String;)Ljava/util/Map;
-	public static fun getDefaultChainTarget (Lspace/kscience/dataforge/context/LogManager;)Ljava/lang/String;
-	public static fun getDefaultTarget (Lspace/kscience/dataforge/context/LogManager;)Ljava/lang/String;
-	public static fun getName (Lspace/kscience/dataforge/context/LogManager;)Lspace/kscience/dataforge/names/Name;
-	public static fun toMeta (Lspace/kscience/dataforge/context/LogManager;)Lspace/kscience/dataforge/meta/Meta;
-}
-
 public final class space/kscience/dataforge/context/LogManagerKt {
-	public static final fun debug (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)V
-	public static synthetic fun debug$default (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
-	public static final fun error (Lspace/kscience/dataforge/context/Logable;Ljava/lang/Throwable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)V
-	public static final fun error (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)V
-	public static synthetic fun error$default (Lspace/kscience/dataforge/context/Logable;Ljava/lang/Throwable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
-	public static synthetic fun error$default (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
+	public static final fun debug (Lspace/kscience/dataforge/context/Logger;Lkotlin/jvm/functions/Function0;)V
+	public static final fun error (Lspace/kscience/dataforge/context/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static final fun error (Lspace/kscience/dataforge/context/Logger;Lkotlin/jvm/functions/Function0;)V
 	public static final fun getLogger (Lspace/kscience/dataforge/context/Context;)Lspace/kscience/dataforge/context/LogManager;
-	public static final fun getLogger (Lspace/kscience/dataforge/context/ContextAware;)Lspace/kscience/dataforge/context/Logable;
-	public static final fun info (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)V
-	public static synthetic fun info$default (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
-	public static final fun trace (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)V
-	public static synthetic fun trace$default (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
-	public static final fun warn (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;)V
-	public static synthetic fun warn$default (Lspace/kscience/dataforge/context/Logable;Lspace/kscience/dataforge/names/Name;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
+	public static final fun getLogger (Lspace/kscience/dataforge/context/ContextAware;)Lspace/kscience/dataforge/context/Logger;
+	public static final fun info (Lspace/kscience/dataforge/context/Logger;Lkotlin/jvm/functions/Function0;)V
+	public static final fun trace (Lspace/kscience/dataforge/context/Logger;Lkotlin/jvm/functions/Function0;)V
+	public static final fun warn (Lspace/kscience/dataforge/context/Logger;Lkotlin/jvm/functions/Function0;)V
 }
 
-public abstract interface class space/kscience/dataforge/context/Logable {
-	public abstract fun log (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;Lkotlin/jvm/functions/Function0;)V
+public abstract interface class space/kscience/dataforge/context/Logger {
+	public abstract fun log (Ljava/lang/String;Lkotlin/jvm/functions/Function0;)V
 }
 
 public abstract interface class space/kscience/dataforge/context/Plugin : space/kscience/dataforge/context/ContextAware, space/kscience/dataforge/meta/MetaRepr, space/kscience/dataforge/misc/Named, space/kscience/dataforge/provider/Provider {
@@ -149,28 +144,36 @@ public abstract interface class space/kscience/dataforge/context/Plugin : space/
 	public abstract fun dependsOn ()Ljava/util/Map;
 	public abstract fun detach ()V
 	public abstract fun getMeta ()Lspace/kscience/dataforge/meta/Meta;
-	public abstract fun getName ()Lspace/kscience/dataforge/names/Name;
+	public fun getName ()Lspace/kscience/dataforge/names/Name;
 	public abstract fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
-	public abstract fun toMeta ()Lspace/kscience/dataforge/meta/Meta;
+	public abstract fun isAttached ()Z
+	public fun toMeta ()Lspace/kscience/dataforge/meta/Meta;
 }
 
 public final class space/kscience/dataforge/context/Plugin$Companion {
 	public static final field TARGET Ljava/lang/String;
 }
 
-public final class space/kscience/dataforge/context/Plugin$DefaultImpls {
-	public static fun content (Lspace/kscience/dataforge/context/Plugin;Ljava/lang/String;)Ljava/util/Map;
-	public static fun getDefaultChainTarget (Lspace/kscience/dataforge/context/Plugin;)Ljava/lang/String;
-	public static fun getDefaultTarget (Lspace/kscience/dataforge/context/Plugin;)Ljava/lang/String;
-	public static fun getName (Lspace/kscience/dataforge/context/Plugin;)Lspace/kscience/dataforge/names/Name;
-	public static fun toMeta (Lspace/kscience/dataforge/context/Plugin;)Lspace/kscience/dataforge/meta/Meta;
+public final class space/kscience/dataforge/context/PluginBuilder {
+	public fun <init> (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V
+	public synthetic fun <init> (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun build ()Lspace/kscience/dataforge/context/PluginFactory;
+	public final fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
+	public final fun provides (Ljava/lang/String;Ljava/util/Map;)V
+	public final fun provides (Ljava/lang/String;[Lspace/kscience/dataforge/misc/Named;)V
+	public final fun requires (Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;)V
+	public static synthetic fun requires$default (Lspace/kscience/dataforge/context/PluginBuilder;Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;ILjava/lang/Object;)V
+}
+
+public final class space/kscience/dataforge/context/PluginBuilderKt {
+	public static final fun PluginFactory (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/PluginFactory;
+	public static synthetic fun PluginFactory$default (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/context/PluginFactory;
 }
 
 public abstract interface class space/kscience/dataforge/context/PluginFactory : space/kscience/dataforge/context/Factory {
 	public static final field Companion Lspace/kscience/dataforge/context/PluginFactory$Companion;
 	public static final field TYPE Ljava/lang/String;
 	public abstract fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
-	public abstract fun getType ()Lkotlin/reflect/KClass;
 }
 
 public final class space/kscience/dataforge/context/PluginFactory$Companion {
@@ -178,25 +181,15 @@ public final class space/kscience/dataforge/context/PluginFactory$Companion {
 }
 
 public final class space/kscience/dataforge/context/PluginManager : java/lang/Iterable, kotlin/jvm/internal/markers/KMappedMarker, space/kscience/dataforge/context/ContextAware {
-	public fun <init> (Lspace/kscience/dataforge/context/Context;)V
-	public final fun fetch (Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;Z)Lspace/kscience/dataforge/context/Plugin;
-	public final fun fetch (Lspace/kscience/dataforge/context/PluginFactory;ZLkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/Plugin;
-	public static synthetic fun fetch$default (Lspace/kscience/dataforge/context/PluginManager;Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;ZILjava/lang/Object;)Lspace/kscience/dataforge/context/Plugin;
-	public static synthetic fun fetch$default (Lspace/kscience/dataforge/context/PluginManager;Lspace/kscience/dataforge/context/PluginFactory;ZLkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/context/Plugin;
 	public final fun find (ZLkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/Plugin;
 	public static synthetic fun find$default (Lspace/kscience/dataforge/context/PluginManager;ZLkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lspace/kscience/dataforge/context/Plugin;
-	public final fun get (Lkotlin/reflect/KClass;Lspace/kscience/dataforge/context/PluginTag;Z)Ljava/lang/Object;
 	public final fun get (Lspace/kscience/dataforge/context/PluginTag;Z)Lspace/kscience/dataforge/context/Plugin;
-	public static synthetic fun get$default (Lspace/kscience/dataforge/context/PluginManager;Lkotlin/reflect/KClass;Lspace/kscience/dataforge/context/PluginTag;ZILjava/lang/Object;)Ljava/lang/Object;
 	public static synthetic fun get$default (Lspace/kscience/dataforge/context/PluginManager;Lspace/kscience/dataforge/context/PluginTag;ZILjava/lang/Object;)Lspace/kscience/dataforge/context/Plugin;
+	public final fun getByType (Lkotlin/reflect/KClass;Lspace/kscience/dataforge/context/PluginTag;Z)Ljava/lang/Object;
+	public static synthetic fun getByType$default (Lspace/kscience/dataforge/context/PluginManager;Lkotlin/reflect/KClass;Lspace/kscience/dataforge/context/PluginTag;ZILjava/lang/Object;)Ljava/lang/Object;
 	public fun getContext ()Lspace/kscience/dataforge/context/Context;
 	public fun iterator ()Ljava/util/Iterator;
 	public final fun list (Z)Ljava/util/Collection;
-	public final fun load (Lspace/kscience/dataforge/context/Plugin;)Lspace/kscience/dataforge/context/Plugin;
-	public final fun load (Lspace/kscience/dataforge/context/PluginFactory;Lkotlin/jvm/functions/Function1;)Lspace/kscience/dataforge/context/Plugin;
-	public final fun load (Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/context/Plugin;
-	public static synthetic fun load$default (Lspace/kscience/dataforge/context/PluginManager;Lspace/kscience/dataforge/context/PluginFactory;Lspace/kscience/dataforge/meta/Meta;ILjava/lang/Object;)Lspace/kscience/dataforge/context/Plugin;
-	public final fun remove (Lspace/kscience/dataforge/context/Plugin;)V
 }
 
 public final class space/kscience/dataforge/context/PluginTag : space/kscience/dataforge/meta/MetaRepr {
@@ -219,14 +212,25 @@ public final class space/kscience/dataforge/context/PluginTag : space/kscience/d
 	public fun toString ()Ljava/lang/String;
 }
 
+public final class space/kscience/dataforge/context/PluginTag$$serializer : kotlinx/serialization/internal/GeneratedSerializer {
+	public static final field INSTANCE Lspace/kscience/dataforge/context/PluginTag$$serializer;
+	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/context/PluginTag;
+	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/context/PluginTag;)V
+	public fun typeParametersSerializers ()[Lkotlinx/serialization/KSerializer;
+}
+
 public final class space/kscience/dataforge/context/PluginTag$Companion {
 	public final fun fromString (Ljava/lang/String;)Lspace/kscience/dataforge/context/PluginTag;
+	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
 public final class space/kscience/dataforge/context/ResolveKt {
 	public static final fun gather (Lspace/kscience/dataforge/context/Context;Ljava/lang/String;Lkotlin/reflect/KClass;Z)Ljava/util/Map;
 	public static synthetic fun gather$default (Lspace/kscience/dataforge/context/Context;Ljava/lang/String;Lkotlin/reflect/KClass;ZILjava/lang/Object;)Ljava/util/Map;
-	public static synthetic fun gatherInSequence$default (Lspace/kscience/dataforge/context/Context;Ljava/lang/String;Lkotlin/reflect/KClass;ZILjava/lang/Object;)Lkotlin/sequences/Sequence;
 	public static final fun getValues (Lkotlin/sequences/Sequence;)Lkotlin/sequences/Sequence;
 	public static final fun resolve (Lspace/kscience/dataforge/context/Context;Ljava/lang/String;Lspace/kscience/dataforge/names/Name;Lkotlin/reflect/KClass;)Ljava/lang/Object;
 }
@@ -234,49 +238,24 @@ public final class space/kscience/dataforge/context/ResolveKt {
 public final class space/kscience/dataforge/context/SlfLogManager : space/kscience/dataforge/context/AbstractPlugin, space/kscience/dataforge/context/LogManager {
 	public static final field Companion Lspace/kscience/dataforge/context/SlfLogManager$Companion;
 	public fun <init> ()V
+	public fun getDefaultLogger ()Lspace/kscience/dataforge/context/Logger;
 	public fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
-	public fun log (Lspace/kscience/dataforge/names/Name;Ljava/lang/String;Lkotlin/jvm/functions/Function0;)V
+	public fun logger (Lspace/kscience/dataforge/names/Name;)Lspace/kscience/dataforge/context/Logger;
 }
 
 public final class space/kscience/dataforge/context/SlfLogManager$Companion : space/kscience/dataforge/context/PluginFactory {
+	public synthetic fun build (Lspace/kscience/dataforge/context/Context;Lspace/kscience/dataforge/meta/Meta;)Ljava/lang/Object;
+	public fun build (Lspace/kscience/dataforge/context/Context;Lspace/kscience/dataforge/meta/Meta;)Lspace/kscience/dataforge/context/SlfLogManager;
 	public fun getTag ()Lspace/kscience/dataforge/context/PluginTag;
-	public fun getType ()Lkotlin/reflect/KClass;
-	public synthetic fun invoke (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/context/Context;)Ljava/lang/Object;
-	public fun invoke (Lspace/kscience/dataforge/meta/Meta;Lspace/kscience/dataforge/context/Context;)Lspace/kscience/dataforge/context/SlfLogManager;
-}
-
-public abstract interface annotation class space/kscience/dataforge/descriptors/Attribute : java/lang/annotation/Annotation {
-	public abstract fun key ()Ljava/lang/String;
-	public abstract fun value ()Ljava/lang/String;
-}
-
-public abstract interface annotation class space/kscience/dataforge/descriptors/Attributes : java/lang/annotation/Annotation {
-	public abstract fun attrs ()[Lspace/kscience/dataforge/descriptors/Attribute;
-}
-
-public abstract interface annotation class space/kscience/dataforge/descriptors/ItemDef : java/lang/annotation/Annotation {
-	public abstract fun info ()Ljava/lang/String;
-	public abstract fun multiple ()Z
-	public abstract fun required ()Z
-}
-
-public abstract interface annotation class space/kscience/dataforge/descriptors/ValueDef : java/lang/annotation/Annotation {
-	public abstract fun allowed ()[Ljava/lang/String;
-	public abstract fun def ()Ljava/lang/String;
-	public abstract fun enumeration ()Ljava/lang/Class;
-	public abstract fun type ()[Lspace/kscience/dataforge/values/ValueType;
-}
-
-public final class space/kscience/dataforge/properties/Property$DefaultImpls {
-	public static synthetic fun onChange$default (Lspace/kscience/dataforge/properties/Property;Ljava/lang/Object;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
-	public static synthetic fun removeChangeListener$default (Lspace/kscience/dataforge/properties/Property;Ljava/lang/Object;ILjava/lang/Object;)V
 }
 
 public final class space/kscience/dataforge/properties/PropertyKt {
 }
 
+public final class space/kscience/dataforge/properties/SchemePropertyKt {
+}
+
 public final class space/kscience/dataforge/provider/DfTypeKt {
-	public static final fun getDfType (Lkotlin/reflect/KClass;)Ljava/lang/String;
 }
 
 public final class space/kscience/dataforge/provider/Path : java/lang/Iterable, kotlin/jvm/internal/markers/KMappedMarker {
@@ -330,19 +309,14 @@ public final class space/kscience/dataforge/provider/PathToken {
 }
 
 public final class space/kscience/dataforge/provider/PathToken$Companion {
-	public final fun parse (Ljava/lang/String;)Lspace/kscience/dataforge/provider/PathToken;
+	public final fun parse (Ljava/lang/String;Z)Lspace/kscience/dataforge/provider/PathToken;
+	public static synthetic fun parse$default (Lspace/kscience/dataforge/provider/PathToken$Companion;Ljava/lang/String;ZILjava/lang/Object;)Lspace/kscience/dataforge/provider/PathToken;
 }
 
 public abstract interface class space/kscience/dataforge/provider/Provider {
-	public abstract fun content (Ljava/lang/String;)Ljava/util/Map;
-	public abstract fun getDefaultChainTarget ()Ljava/lang/String;
-	public abstract fun getDefaultTarget ()Ljava/lang/String;
-}
-
-public final class space/kscience/dataforge/provider/Provider$DefaultImpls {
-	public static fun content (Lspace/kscience/dataforge/provider/Provider;Ljava/lang/String;)Ljava/util/Map;
-	public static fun getDefaultChainTarget (Lspace/kscience/dataforge/provider/Provider;)Ljava/lang/String;
-	public static fun getDefaultTarget (Lspace/kscience/dataforge/provider/Provider;)Ljava/lang/String;
+	public fun content (Ljava/lang/String;)Ljava/util/Map;
+	public fun getDefaultChainTarget ()Ljava/lang/String;
+	public fun getDefaultTarget ()Ljava/lang/String;
 }
 
 public final class space/kscience/dataforge/provider/ProviderKt {

dataforge-context/build.gradle.kts

@@ -1,35 +1,24 @@
 plugins {
-    id("ru.mipt.npm.gradle.mpp")
-    id("ru.mipt.npm.gradle.native")
+    id("space.kscience.gradle.mpp")
 }
 
 description = "Context and provider definitions"
 
 kscience {
+    jvm()
+    js()
+    native()
     useCoroutines()
-}
-
-kotlin {
-    sourceSets {
-        val commonMain by getting{
-            dependencies {
-                api(project(":dataforge-meta"))
-            }
-        }
-        jvmMain {
-            dependencies {
-                api(kotlin("reflect"))
-                api("org.slf4j:slf4j-api:1.7.30")
-            }
-        }
-        jsMain {
-            dependencies {
-
-            }
-        }
+    useSerialization()
+    dependencies {
+        api(project(":dataforge-meta"))
+    }
+    dependencies(jvmMain){
+        api(kotlin("reflect"))
+        api("org.slf4j:slf4j-api:1.7.30")
     }
 }
 
-readme{
-    maturity = ru.mipt.npm.gradle.Maturity.DEVELOPMENT
+readme {
+    maturity = space.kscience.gradle.Maturity.DEVELOPMENT
 }

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

@@ -1,6 +1,7 @@
 package space.kscience.dataforge.context
 
 import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.misc.DFInternal
 import space.kscience.dataforge.misc.Named
 import space.kscience.dataforge.names.Name
 import kotlin.properties.ReadOnlyProperty
@@ -11,6 +12,8 @@ public abstract class AbstractPlugin(override val meta: Meta = Meta.EMPTY) : Plu
     private var _context: Context? = null
     private val dependencies = HashMap<PluginFactory<*>, Meta>()
 
+    override val isAttached: Boolean get() = _context != null
+
     override val context: Context
         get() = _context ?: error("Plugin $tag is not attached")
 
@@ -22,21 +25,33 @@ public abstract class AbstractPlugin(override val meta: Meta = Meta.EMPTY) : Plu
         this._context = null
     }
 
-    final override fun dependsOn(): Map<PluginFactory<*>, Meta> = dependencies
+    override fun dependsOn(): Map<PluginFactory<*>, Meta> = dependencies
+
+    protected fun <P : Plugin> require(
+        factory: PluginFactory<P>,
+        type: KClass<P>,
+        meta: Meta = Meta.EMPTY,
+    ): ReadOnlyProperty<AbstractPlugin, P> {
+        dependencies[factory] = meta
+        return PluginDependencyDelegate(factory, type)
+    }
 
     /**
      * Register plugin dependency and return a delegate which provides lazily initialized reference to dependent plugin
      */
-    protected fun <P : Plugin> require(factory: PluginFactory<P>, meta: Meta = Meta.EMPTY): ReadOnlyProperty<AbstractPlugin, P> {
-        dependencies[factory] = meta
-        return PluginDependencyDelegate(factory.type)
-    }
+    protected inline fun <reified P : Plugin> require(
+        factory: PluginFactory<P>,
+        meta: Meta = Meta.EMPTY,
+    ): ReadOnlyProperty<AbstractPlugin, P> = require(factory, P::class, meta)
 }
 
-public fun <T : Named> Collection<T>.toMap(): Map<Name, T> = associate { it.name to it }
+public fun <T : Named> Collection<T>.associateByName(): Map<Name, T> = associate { it.name to it }
 
-private class PluginDependencyDelegate<P : Plugin>(val type: KClass<out P>) : ReadOnlyProperty<AbstractPlugin, P> {
+private class PluginDependencyDelegate<P : Plugin>(val factory: PluginFactory<P>, val type: KClass<P>) :
+    ReadOnlyProperty<AbstractPlugin, P> {
+    @OptIn(DFInternal::class)
     override fun getValue(thisRef: AbstractPlugin, property: KProperty<*>): P {
-        return thisRef.context.plugins[type] ?: error("Plugin with type $type not found")
+        if (!thisRef.isAttached) error("Plugin dependency must not be called eagerly during initialization.")
+        return thisRef.context.plugins.getByType(type, factory.tag) ?: error("Plugin ${factory.tag} not found")
     }
 }

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

@@ -3,11 +3,10 @@ package space.kscience.dataforge.context
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.SupervisorJob
-import space.kscience.dataforge.meta.Laminate
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaRepr
-import space.kscience.dataforge.meta.itemSequence
+import space.kscience.dataforge.meta.*
+import space.kscience.dataforge.misc.DFExperimental
 import space.kscience.dataforge.misc.Named
+import space.kscience.dataforge.misc.ThreadSafe
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.provider.Provider
 import kotlin.coroutines.CoroutineContext
@@ -25,35 +24,37 @@ import kotlin.coroutines.CoroutineContext
 public open class Context internal constructor(
     final override val name: Name,
     public val parent: Context?,
+    plugins: Set<Plugin>, // set of unattached plugins
     meta: Meta,
 ) : Named, MetaRepr, Provider, CoroutineScope {
 
     /**
      * Context properties. Working as substitute for environment variables
      */
-    private val properties: Laminate = if (parent == null) {
+    public val properties: Laminate = if (parent == null) {
         Laminate(meta)
     } else {
         Laminate(meta, parent.properties)
     }
 
+
     /**
      * A [PluginManager] for current context
      */
-    public val plugins: PluginManager by lazy { PluginManager(this) }
+    public val plugins: PluginManager by lazy { PluginManager(this, plugins) }
 
     override val defaultTarget: String get() = Plugin.TARGET
 
     public fun content(target: String, inherit: Boolean): Map<Name, Any> {
         return if (inherit) {
             when (target) {
-                PROPERTY_TARGET -> properties.itemSequence().toMap()
+                PROPERTY_TARGET -> properties.nodeSequence().toMap()
                 Plugin.TARGET -> plugins.list(true).associateBy { it.name }
                 else -> emptyMap()
             }
         } else {
             when (target) {
-                PROPERTY_TARGET -> properties.layers.firstOrNull()?.itemSequence()?.toMap() ?: emptyMap()
+                PROPERTY_TARGET -> properties.layers.firstOrNull()?.nodeSequence()?.toMap() ?: emptyMap()
                 Plugin.TARGET -> plugins.list(false).associateBy { it.name }
                 else -> emptyMap()
             }
@@ -68,18 +69,35 @@ public open class Context internal constructor(
         }
     }
 
+    private val childrenContexts = HashMap<Name, Context>()
+
     /**
-     * Detach all plugins and terminate context
+     * Get and validate existing context or build and register a new child context.
+     * @param name the relative (tail) name of the new context. If null, uses context hash code as a marker.
+     */
+    @OptIn(DFExperimental::class)
+    @ThreadSafe
+    public fun buildContext(name: Name? = null, block: ContextBuilder.() -> Unit = {}): Context {
+        val existing = name?.let { childrenContexts[name] }
+        return existing?.modify(block) ?: ContextBuilder(this, name).apply(block).build().also {
+            childrenContexts[it.name] = it
+        }
+    }
+
+    /**
+     * Detach all plugins, and close child contexts
      */
     public open fun close() {
+        //recursively closed child context
+        childrenContexts.forEach { it.value.close() }
         //detach all plugins
         plugins.forEach { it.detach() }
     }
 
     override fun toMeta(): Meta = Meta {
         "parent" to parent?.name
-        "properties" put properties.layers.firstOrNull()
-        "plugins" put plugins.map { it.toMeta() }
+        properties.layers.firstOrNull()?.let { set("properties", it) }
+        "plugins" putIndexed plugins.map { it.toMeta() }
     }
 
     public companion object {
@@ -87,9 +105,6 @@ public open class Context internal constructor(
     }
 }
 
-public fun Context(name: String, parent: Context = Global, block: ContextBuilder.() -> Unit = {}): Context =
-    Global.context(name, parent, block)
-
 /**
  * The interface for something that encapsulated in context
  *

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

@@ -1,11 +1,15 @@
 package space.kscience.dataforge.context
 
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
+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.names.toName
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.NameToken
+import space.kscience.dataforge.names.asName
+import space.kscience.dataforge.names.plus
 import kotlin.collections.component1
 import kotlin.collections.component2
 import kotlin.collections.set
@@ -14,11 +18,15 @@ import kotlin.collections.set
  * A convenience builder for context
  */
 @DFBuilder
-public class ContextBuilder(private val parent: Context = Global, public var name: String = "@anonymous") {
-    private val factories = HashMap<PluginFactory<*>, Meta>()
-    private var meta = MetaBuilder()
+public class ContextBuilder internal constructor(
+    private val parent: Context,
+    public val name: Name? = null,
+    meta: Meta = Meta.EMPTY,
+) {
+    internal val factories = HashMap<PluginFactory<*>, Meta>()
+    internal var meta = meta.toMutableMeta()
 
-    public fun properties(action: MetaBuilder.() -> Unit) {
+    public fun properties(action: MutableMeta.() -> Unit) {
         meta.action()
     }
 
@@ -27,24 +35,77 @@ public class ContextBuilder(private val parent: Context = Global, public var nam
         parent.gatherInSequence<PluginFactory<*>>(PluginFactory.TYPE).values
             .find { it.tag.matches(tag) } ?: error("Can't resolve plugin factory for $tag")
 
-    public fun plugin(tag: PluginTag, metaBuilder: MetaBuilder.() -> Unit = {}) {
+    public fun plugin(tag: PluginTag, mutableMeta: MutableMeta.() -> Unit = {}) {
         val factory = findPluginFactory(tag)
-        factories[factory] = Meta(metaBuilder)
+        factories[factory] = Meta(mutableMeta)
     }
 
-    public fun plugin(factory: PluginFactory<*>, metaBuilder: MetaBuilder.() -> Unit = {}) {
-        factories[factory] = Meta(metaBuilder)
+    public fun plugin(factory: PluginFactory<*>, meta: Meta) {
+        factories[factory] = meta
     }
 
-    public fun plugin(name: String, group: String = "", version: String = "", action: MetaBuilder.() -> Unit = {}) {
+    public fun plugin(factory: PluginFactory<*>, mutableMeta: MutableMeta.() -> Unit = {}) {
+        factories[factory] = Meta(mutableMeta)
+    }
+
+    public fun plugin(name: String, group: String = "", version: String = "", action: MutableMeta.() -> Unit = {}) {
         plugin(PluginTag(name, group, version), action)
     }
 
-    public fun build(): Context {
-        return Context(name.toName(), parent, meta.seal()).apply {
-            factories.forEach { (factory, meta) ->
-                plugins.load(factory, meta)
-            }
-        }
+    /**
+     * Add de-facto existing plugin as a dependency
+     */
+    public fun plugin(plugin: Plugin) {
+        plugin(DeFactoPluginFactory(plugin))
     }
+
+    public fun build(): Context {
+        val contextName = name ?: NameToken("@auto",hashCode().toUInt().toString(16)).asName()
+        val plugins = HashMap<PluginTag, Plugin>()
+
+        fun addPlugin(factory: PluginFactory<*>, meta: Meta) {
+            val existing = plugins[factory.tag]
+            // Add if does not exist
+            if (existing == null) {
+                //TODO bypass if parent already has plugin with given meta?
+                val plugin = factory.build(parent, meta)
+
+                for ((depFactory, deoMeta) in plugin.dependsOn()) {
+                    addPlugin(depFactory, deoMeta)
+                }
+
+                parent.logger.info { "Loading plugin ${plugin.name} into $contextName" }
+                plugins[plugin.tag] = plugin
+            } else if (existing.meta != meta) {
+                error("Plugin with tag ${factory.tag} and meta $meta already exists in $contextName")
+            }
+            //bypass if exists with the same meta
+        }
+
+        factories.forEach { (factory, meta) ->
+            addPlugin(factory, meta)
+        }
+
+        return Context(contextName, parent, plugins.values.toSet(), meta.seal())
+    }
+}
+
+/**
+ * Check if current context contains all plugins required by the builder and return it does or forks to a new context
+ * if it does not.
+ */
+@DFExperimental
+public fun Context.modify(block: ContextBuilder.() -> Unit): Context {
+
+    fun Context.contains(factory: PluginFactory<*>, meta: Meta): Boolean {
+        val loaded = plugins[factory.tag] ?: return false
+        return loaded.meta == meta
+    }
+
+    val builder = ContextBuilder(this, name + "mod", properties).apply(block)
+    val requiresFork = builder.factories.any { (factory, meta) ->
+        !contains(factory, meta)
+    } || ((properties as Meta) == builder.meta)
+
+    return if (requiresFork) builder.build() else this
 }

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

@@ -2,6 +2,11 @@ package space.kscience.dataforge.context
 
 import space.kscience.dataforge.meta.Meta
 
-public interface Factory<out T : Any> {
-    public operator fun invoke(meta: Meta = Meta.EMPTY, context: Context = Global): T
-}
+public fun interface Factory<out T> {
+    public fun build(context: Context, meta: Meta): T
+}
+
+public operator fun <T> Factory<T>.invoke(
+    meta: Meta = Meta.EMPTY,
+    context: Context = Global,
+): T = build(context, meta)

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

@@ -1,55 +1,24 @@
 package space.kscience.dataforge.context
 
-import kotlinx.coroutines.GlobalScope
-import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.Job
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.names.asName
+import space.kscience.dataforge.names.parseAsName
 import kotlin.coroutines.CoroutineContext
 import kotlin.native.concurrent.ThreadLocal
 
-internal expect val globalLoggerFactory: PluginFactory<out LogManager>
+internal expect fun getGlobalLoggerFactory(): PluginFactory<out LogManager>
 
 /**
  * A global root context. Closing [Global] terminates the framework.
  */
 @ThreadLocal
-public object Global : Context("GLOBAL".asName(), null, Meta.EMPTY) {
+private object GlobalContext : Context("GLOBAL".asName(), null, emptySet(), Meta.EMPTY) {
+    override val coroutineContext: CoroutineContext = Job() + CoroutineName("GlobalContext")
+}
 
-    override val coroutineContext: CoroutineContext = GlobalScope.coroutineContext + SupervisorJob()
+public val Global: Context get() = GlobalContext
 
-    /**
-     * The default logging manager
-     */
-    public val logger: LogManager by lazy { globalLoggerFactory.invoke(context = this).apply { attach(this@Global) } }
-
-    /**
-     * Closing all contexts
-     *
-     * @throws Exception
-     */
-    override fun close() {
-        logger.info { "Shutting down GLOBAL" }
-        for (ctx in contextRegistry.values) {
-            ctx.close()
-        }
-        super.close()
-    }
-
-    private val contextRegistry = HashMap<String, Context>()
-
-    /**
-     * Get previously built context
-     *
-     * @param name
-     * @return
-     */
-    public fun getContext(name: String): Context? {
-        return contextRegistry[name]
-    }
-
-    public fun context(name: String, parent: Context = this, block: ContextBuilder.() -> Unit = {}): Context =
-        ContextBuilder(parent, name).apply(block).build().also {
-            contextRegistry[name] = it
-        }
-
-}
+public fun Context(name: String? = null, block: ContextBuilder.() -> Unit = {}): Context =
+    Global.buildContext(name?.parseAsName(), block)

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

@@ -1,14 +1,22 @@
 package space.kscience.dataforge.context
 
+import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.misc.Named
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.plus
 
-public interface Logable {
-    public fun log(name: Name, tag: String, body: () -> String)
+public fun interface Logger {
+    public fun log(tag: String, body: () -> String)
 }
 
-public interface LogManager : Plugin, Logable {
+public interface LogManager : Plugin, Logger {
+    public fun logger(name: Name): Logger
+
+    public val defaultLogger: Logger
+
+    override fun log(tag: String, body: () -> String): Unit = defaultLogger.log(tag, body)
+
+    public fun log(name: Name, tag: String, body: () -> String): Unit = logger(name).log(tag, body)
 
     public companion object {
         public const val TRACE: String = "TRACE"
@@ -19,11 +27,11 @@ public interface LogManager : Plugin, Logable {
     }
 }
 
-public fun Logable.trace(name: Name = Name.EMPTY, body: () -> String): Unit = log(name, LogManager.TRACE, body)
-public fun Logable.info(name: Name = Name.EMPTY, body: () -> String): Unit = log(name, LogManager.INFO, body)
-public fun Logable.debug(name: Name = Name.EMPTY, body: () -> String): Unit = log(name, LogManager.DEBUG, body)
-public fun Logable.warn(name: Name = Name.EMPTY, body: () -> String): Unit = log(name, LogManager.WARNING, body)
-public fun Logable.error(name: Name = Name.EMPTY, body: () -> String): Unit = log(name, LogManager.ERROR, body)
+public fun Logger.trace(body: () -> String): Unit = log(LogManager.TRACE, body)
+public fun Logger.info(body: () -> String): Unit = log(LogManager.INFO, body)
+public fun Logger.debug(body: () -> String): Unit = log(LogManager.DEBUG, body)
+public fun Logger.warn(body: () -> String): Unit = log(LogManager.WARNING, body)
+public fun Logger.error(body: () -> String): Unit = log(LogManager.ERROR, body)
 
 internal val (() -> String).safe: String
     get() = try {
@@ -33,30 +41,47 @@ internal val (() -> String).safe: String
     }
 
 
-public fun Logable.error(throwable: Throwable?, name: Name = Name.EMPTY, body: () -> String): Unit =
-    log(name, LogManager.ERROR) {
-        buildString {
-            appendLine(body())
-            throwable?.let { appendLine(throwable.stackTraceToString()) }
-        }
+public fun Logger.error(throwable: Throwable?, body: () -> String): Unit = log(LogManager.ERROR) {
+    buildString {
+        appendLine(body())
+        throwable?.let { appendLine(throwable.stackTraceToString()) }
     }
+}
+
+
+public class DefaultLogManager : AbstractPlugin(), LogManager {
+
+    override fun logger(name: Name): Logger = Logger { tag, body ->
+        val message: String = body.safe
+        println("$tag $name: [${context.name}] $message")
+    }
+
+    override val defaultLogger: Logger = logger(Name.EMPTY)
+
+
+    override val tag: PluginTag get() = Companion.tag
+
+    public companion object : PluginFactory<DefaultLogManager> {
+        override fun build(context: Context, meta: Meta): DefaultLogManager = DefaultLogManager()
+
+        override val tag: PluginTag = PluginTag(group = PluginTag.DATAFORGE_GROUP, name = "log.default")
+    }
+}
 
 /**
  * Context log manager inherited from parent
  */
 public val Context.logger: LogManager
-    get() = plugins.find(inherit = true) { it is LogManager } as? LogManager ?: Global.logger
+    get() = plugins.find(inherit = true) { it is LogManager } as? LogManager
+        ?: getGlobalLoggerFactory().build(context = Global, meta = Meta.EMPTY).apply { attach(Global) }
 
 /**
  * The named proxy logger for a context member
  */
-public val ContextAware.logger: Logable
+public val ContextAware.logger: Logger
     get() = if (this is Named) {
-        object : Logable {
-            val contextLog = context.logger
-            override fun log(name: Name, tag: String, body: () -> String) {
-                contextLog.log(this@logger.name + name, tag, body)
-            }
+        Logger { tag, body ->
+            context.logger.log(this@logger.name + name, tag, body)
         }
     } else {
         context.logger

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

@@ -3,10 +3,10 @@ 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.Named
-import space.kscience.dataforge.misc.Type
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.toName
+import space.kscience.dataforge.names.parseAsName
 import space.kscience.dataforge.provider.Provider
 
 /**
@@ -18,7 +18,7 @@ import space.kscience.dataforge.provider.Provider
  *
  * create - configure - attach - detach - destroy
  */
-@Type(TARGET)
+@DfId(TARGET)
 public interface Plugin : Named, ContextAware, Provider, MetaRepr {
 
     /**
@@ -31,7 +31,7 @@ public interface Plugin : Named, ContextAware, Provider, MetaRepr {
     /**
      * The name of this plugin ignoring version and group
      */
-    override val name: Name get() = tag.name.toName()
+    override val name: Name get() = tag.name.parseAsName()
 
     /**
      * Plugin dependencies which are required to attach this plugin. Plugin
@@ -53,6 +53,8 @@ public interface Plugin : Named, ContextAware, Provider, MetaRepr {
      */
     public fun detach()
 
+    public val isAttached: Boolean
+
     override fun toMeta(): Meta = Meta {
         "context" put context.name.toString()
         "type" to this::class.simpleName
@@ -63,5 +65,4 @@ public interface Plugin : Named, ContextAware, Provider, MetaRepr {
     public companion object {
         public const val TARGET: String = "plugin"
     }
-
 }

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

@@ -0,0 +1,57 @@
+package space.kscience.dataforge.context
+
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.misc.Named
+import space.kscience.dataforge.names.Name
+
+/**
+ * A convenience factory to build simple plugins
+ */
+public class PluginBuilder(
+    name: String,
+    group: String = "",
+    version: String = "",
+) {
+    public val tag: PluginTag = PluginTag(name, group, version)
+
+    private val content = HashMap<String, MutableMap<Name, Any>>()
+    private val dependencies = HashMap<PluginFactory<*>, Meta>()
+
+    public fun requires(
+        factory: PluginFactory<*>,
+        meta: Meta = Meta.EMPTY,
+    ) {
+        dependencies[factory] = meta
+    }
+
+    public fun provides(target: String, items: Map<Name, Any>) {
+        content.getOrPut(target) { HashMap() }.putAll(items)
+    }
+
+    public fun provides(target: String, vararg items: Named) {
+        provides(target, items.associateBy { it.name })
+    }
+
+    public fun build(): PluginFactory<*> {
+
+        return object : PluginFactory<Plugin> {
+            override val tag: PluginTag get() = this@PluginBuilder.tag
+
+            override fun build(context: Context, meta: Meta): Plugin = object : AbstractPlugin() {
+                override val tag: PluginTag get() = this@PluginBuilder.tag
+
+                override fun content(target: String): Map<Name, Any> = this@PluginBuilder.content[target] ?: emptyMap()
+
+                override fun dependsOn(): Map<PluginFactory<*>, Meta> = this@PluginBuilder.dependencies
+            }
+
+        }
+    }
+}
+
+public fun PluginFactory(
+    name: String,
+    group: String = "",
+    version: String = "",
+    block: PluginBuilder.() -> Unit,
+): PluginFactory<*> = PluginBuilder(name, group, version).apply(block).build()

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

@@ -1,14 +1,21 @@
 package space.kscience.dataforge.context
 
-import space.kscience.dataforge.misc.Type
-import kotlin.reflect.KClass
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.misc.DfId
 
-@Type(PluginFactory.TYPE)
+@DfId(PluginFactory.TYPE)
 public interface PluginFactory<T : Plugin> : Factory<T> {
     public val tag: PluginTag
-    public val type: KClass<out T>
 
     public companion object {
         public const val TYPE: String = "pluginFactory"
     }
 }
+
+/**
+ * Plugin factory created for the specific actual plugin
+ */
+internal class DeFactoPluginFactory<T : Plugin>(val plugin: T) : PluginFactory<T> {
+    override fun build(context: Context, meta: Meta): T = plugin
+    override val tag: PluginTag get() = plugin.tag
+}

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

@@ -1,8 +1,10 @@
 package space.kscience.dataforge.context
 
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
+import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.names.plus
 import kotlin.reflect.KClass
+import kotlin.reflect.cast
 
 
 /**
@@ -11,14 +13,10 @@ import kotlin.reflect.KClass
  * @property context A context for this plugin manager
  * @author Alexander Nozik
  */
-public class PluginManager(override val context: Context) : ContextAware, Iterable<Plugin> {
-
-    //TODO refactor to read-only container
-
-    /**
-     * A set of loaded plugins
-     */
-    private val plugins: HashSet<Plugin> = HashSet()
+public class PluginManager internal constructor(
+    override val context: Context,
+    private val plugins: Set<Plugin>,
+) : ContextAware, Iterable<Plugin> {
 
     init {
         plugins.forEach { it.attach(context) }
@@ -68,76 +66,35 @@ public class PluginManager(override val context: Context) : ContextAware, Iterab
      * @param <T>
      * @return
      */
-    @Suppress("UNCHECKED_CAST")
-    public operator fun <T : Any> get(type: KClass<out T>, tag: PluginTag? = null, recursive: Boolean = true): T? =
-        find(recursive) { type.isInstance(it) && (tag == null || tag.matches(it.tag)) } as T?
+    @DFInternal
+    public fun <T : Any> getByType(type: KClass<T>, tag: PluginTag? = null, inherit: Boolean = true): T? =
+        find(inherit) { type.isInstance(it) && (tag == null || tag.matches(it.tag)) }?.let { type.cast(it) }
 
+    @OptIn(DFInternal::class)
     public inline operator fun <reified T : Any> get(tag: PluginTag? = null, recursive: Boolean = true): T? =
-        get(T::class, tag, recursive)
+        getByType(T::class, tag, recursive)
 
+    @OptIn(DFInternal::class)
     public inline operator fun <reified T : Plugin> get(factory: PluginFactory<T>, recursive: Boolean = true): T? =
-        get(factory.type, factory.tag, recursive)
-
-    /**
-     * Load given plugin into this manager and return loaded instance.
-     * Throw error if plugin of the same type and tag already exists in manager.
-     *
-     * @param plugin
-     * @return
-     */
-    public fun <T : Plugin> load(plugin: T): T {
-        if (get(plugin::class, plugin.tag, recursive = false) != null) {
-            error("Plugin with tag ${plugin.tag} already exists in ${context.name}")
-        } else {
-            for ((factory, meta) in plugin.dependsOn()) {
-                fetch(factory, meta, true)
-            }
-
-            Global.logger.info { "Loading plugin ${plugin.name} into ${context.name}" }
-            plugin.attach(context)
-            plugins.add(plugin)
-            return plugin
-        }
-    }
-
-    /**
-     * Load a plugin using its factory
-     */
-    public fun <T : Plugin> load(factory: PluginFactory<T>, meta: Meta = Meta.EMPTY): T =
-        load(factory(meta, context))
-
-    public fun <T : Plugin> load(factory: PluginFactory<T>, metaBuilder: MetaBuilder.() -> Unit): T =
-        load(factory, Meta(metaBuilder))
-
-    /**
-     * Remove a plugin from [PluginManager]
-     */
-    public fun remove(plugin: Plugin) {
-        if (plugins.contains(plugin)) {
-            Global.logger.info { "Removing plugin ${plugin.name} from ${context.name}" }
-            plugin.detach()
-            plugins.remove(plugin)
-        }
-    }
-
-    /**
-     * Get an existing plugin with given meta or load new one using provided factory
-     */
-    public fun <T : Plugin> fetch(factory: PluginFactory<T>, meta: Meta = Meta.EMPTY, recursive: Boolean = true): T {
-        val loaded = get(factory.type, factory.tag, recursive)
-        return when {
-            loaded == null -> load(factory(meta, context))
-            loaded.meta == meta -> loaded // if meta is the same, return existing plugin
-            else -> throw RuntimeException("Can't load plugin with tag ${factory.tag}. Plugin with this tag and different configuration already exists in context.")
-        }
-    }
-
-    public fun <T : Plugin> fetch(
-        factory: PluginFactory<T>,
-        recursive: Boolean = true,
-        metaBuilder: MetaBuilder.() -> Unit,
-    ): T = fetch(factory, Meta(metaBuilder), recursive)
+        getByType(T::class, factory.tag, recursive)
 
     override fun iterator(): Iterator<Plugin> = plugins.iterator()
+}
 
-}
+/**
+ * Fetch a plugin with given meta from the context. If the plugin (with given meta) is already registered, it is returned.
+ * Otherwise, new child context with the plugin is created. In the later case the context could be retrieved from the plugin.
+ */
+public inline fun <reified T : Plugin> Context.request(factory: PluginFactory<T>, meta: Meta = Meta.EMPTY): T {
+    val existing = plugins[factory]
+    return if (existing != null && existing.meta == meta) existing
+    else {
+        buildContext(name = this@request.name + factory.tag.name) {
+            plugin(factory, meta)
+        }.plugins[factory]!!
+    }
+}
+
+@Deprecated("Replace with request", ReplaceWith("request(factory, meta)"))
+public inline fun <reified T : Plugin> Context.fetch(factory: PluginFactory<T>, meta: Meta = Meta.EMPTY): T =
+    request(factory, meta)

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

@@ -1,5 +1,6 @@
 package space.kscience.dataforge.context
 
+import kotlinx.serialization.Serializable
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.MetaRepr
 
@@ -9,6 +10,7 @@ import space.kscience.dataforge.meta.MetaRepr
  *
  * @author Alexander Nozik
  */
+@Serializable
 public data class PluginTag(
     val name: String,
     val group: String = "",

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

@@ -1,34 +0,0 @@
-package space.kscience.dataforge.properties
-
-import space.kscience.dataforge.meta.Config
-import space.kscience.dataforge.meta.get
-import space.kscience.dataforge.meta.set
-import space.kscience.dataforge.meta.transformations.MetaConverter
-import space.kscience.dataforge.meta.transformations.nullableItemToObject
-import space.kscience.dataforge.meta.transformations.nullableObjectToMetaItem
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.Name
-
-@DFExperimental
-public class ConfigProperty<T : Any>(
-    public val config: Config,
-    public val name: Name,
-    public val converter: MetaConverter<T>,
-) : Property<T?> {
-
-    override var value: T?
-        get() = converter.nullableItemToObject(config[name])
-        set(value) {
-            config[name] = converter.nullableObjectToMetaItem(value)
-        }
-
-    override fun onChange(owner: Any?, callback: (T?) -> Unit) {
-        config.onChange(owner) { name, oldItem, newItem ->
-            if (name == this.name && oldItem != newItem) callback(converter.nullableItemToObject(newItem))
-        }
-    }
-
-    override fun removeChangeListener(owner: Any?) {
-        config.removeListener(owner)
-    }
-}

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

@@ -0,0 +1,35 @@
+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

@@ -1,6 +1,5 @@
 package space.kscience.dataforge.properties
 
-import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -23,12 +22,12 @@ public fun <T> Property<T>.toFlow(): StateFlow<T> = MutableStateFlow(value).also
 }
 
 /**
- * Reflect all changes in the [source] property onto this property
+ * 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>, scope: CoroutineScope) {
+public fun <T> Property<T>.mirror(source: Property<T>) {
     source.onChange(this) {
         this.value = it
     }

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

@@ -0,0 +1,31 @@
+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/commonMain/kotlin/space/kscience/dataforge/provider/Path.kt

@@ -16,13 +16,15 @@
 package space.kscience.dataforge.provider
 
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.toName
+import space.kscience.dataforge.names.parseAsName
+import kotlin.jvm.JvmInline
 
 /**
  * Path interface.
  *
  */
-public inline class Path(public val tokens: List<PathToken>) : Iterable<PathToken> {
+@JvmInline
+public value class Path(public val tokens: List<PathToken>) : Iterable<PathToken> {
 
     override fun iterator(): Iterator<PathToken> = tokens.iterator()
 
@@ -31,11 +33,7 @@ public inline class Path(public val tokens: List<PathToken>) : Iterable<PathToke
     public companion object {
         public const val PATH_SEGMENT_SEPARATOR: String = "/"
 
-        public fun parse(path: String): Path {
-            val head = path.substringBefore(PATH_SEGMENT_SEPARATOR)
-            val tail = path.substringAfter(PATH_SEGMENT_SEPARATOR)
-            return PathToken.parse(head).asPath() + parse(tail)
-        }
+        public fun parse(path: String): Path = Path(path.split(PATH_SEGMENT_SEPARATOR).map { PathToken.parse(it) })
     }
 }
 
@@ -63,9 +61,10 @@ public data class PathToken(val name: Name, val target: String? = null) {
 
     public companion object {
         public const val TARGET_SEPARATOR: String = "::"
-        public fun parse(token: String): PathToken {
+
+        public fun parse(token: String, cache: Boolean = false): PathToken {
             val target = token.substringBefore(TARGET_SEPARATOR, "")
-            val name = token.substringAfter(TARGET_SEPARATOR).toName()
+            val name = token.substringAfter(TARGET_SEPARATOR).parseAsName(cache)
             if (target.contains("[")) TODO("target separators in queries are not supported")
             return PathToken(name, target)
         }

dataforge-context/src/commonMain/kotlin/space/kscience/dataforge/provider/Provider.kt

@@ -75,10 +75,8 @@ public inline fun <reified T : Any> Provider.provide(path: String, targetOverrid
 /**
  *  Typed top level content
  */
-public fun <T : Any> Provider.top(target: String, type: KClass<out T>): Map<Name, T> {
-    return content(target).mapValues {
-        type.safeCast(it.value) ?: error("The type of element $it is ${it::class} but $type is expected")
-    }
+public fun <T : Any> Provider.top(target: String, type: KClass<out T>): Map<Name, T> = content(target).mapValues {
+    type.safeCast(it.value) ?: error("The type of element ${it.value} is ${it.value::class} but $type is expected")
 }
 
 /**

dataforge-context/src/commonTest/kotlin/space/kscience/dataforge/context/ContextTest.kt

@@ -1,8 +1,7 @@
 package space.kscience.dataforge.context
 
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.appendLeft
-import space.kscience.dataforge.names.toName
+import space.kscience.dataforge.names.appendFirst
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -12,23 +11,22 @@ class ContextTest {
         override val tag get() = PluginTag("test")
 
         override fun content(target: String): Map<Name, Any> {
-            return when(target){
-                "test" -> listOf("a", "b", "c.d").associate { it.toName() to it.toName() }
+            return when (target) {
+                "test" -> listOf("a", "b", "c.d").associate { Name.parse(it) to Name.parse(it) }
                 else -> emptyMap()
             }
         }
-
     }
 
     @Test
     fun testPluginManager() {
-        val context = Global.context("test")
-        context.plugins.load(DummyPlugin())
-        //Global.plugins.load(DummyPlugin())
+        val context = Context("test") {
+            plugin(DummyPlugin())
+        }
         val members = context.gather<Name>("test")
         assertEquals(3, members.count())
         members.forEach {
-            assertEquals(it.key, it.value.appendLeft("test"))
+            assertEquals(it.key, it.value.appendFirst("test"))
         }
     }
 

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

@@ -0,0 +1,28 @@
+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/commonTest/kotlin/space/kscience/dataforge/provider/PathTest.kt

@@ -0,0 +1,14 @@
+package space.kscience.dataforge.provider
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class PathTest {
+    @Test
+    fun testParse(){
+        val nameString = "a.b.c.d"
+        val pathString = "a.b/c.d"
+        assertEquals(1, Path.parse(nameString).length)
+        assertEquals(2, Path.parse(pathString).length)
+    }
+}

dataforge-context/src/jsMain/kotlin/space/kscience/dataforge/context/loggingJs.kt

@@ -2,13 +2,14 @@ package space.kscience.dataforge.context
 
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.names.Name
-import kotlin.reflect.KClass
 
 public class ConsoleLogManager : AbstractPlugin(), LogManager {
 
-    override fun log(name: Name, tag: String, body: () -> String) {
+    override fun logger(name: Name): Logger  = Logger { tag, body ->
         val message: String = body.safe
         when (tag) {
+            // TODO depends on https://youtrack.jetbrains.com/issue/KT-33595/
+            LogManager.DEBUG -> console.asDynamic().debug("[${context.name}] $name: $message")
             LogManager.INFO -> console.info("[${context.name}] $name: $message")
             LogManager.WARNING ->  console.warn("[${context.name}] $name: $message")
             LogManager.ERROR -> console.error("[${context.name}] $name: $message")
@@ -16,14 +17,16 @@ public class ConsoleLogManager : AbstractPlugin(), LogManager {
         }
     }
 
+    override val defaultLogger: Logger = logger(Name.EMPTY)
+
+
     override val tag: PluginTag get() = Companion.tag
 
     public companion object : PluginFactory<ConsoleLogManager> {
-        override fun invoke(meta: Meta, context: Context): ConsoleLogManager = ConsoleLogManager()
+        override fun build(context: Context, meta: Meta): ConsoleLogManager = ConsoleLogManager()
 
         override val tag: PluginTag = PluginTag(group = PluginTag.DATAFORGE_GROUP, name = "log.jsConsole")
-        override val type: KClass<out ConsoleLogManager> = ConsoleLogManager::class
     }
 }
 
-internal actual val globalLoggerFactory: PluginFactory<out LogManager> = ConsoleLogManager
+internal actual fun getGlobalLoggerFactory(): PluginFactory<out LogManager> = ConsoleLogManager

dataforge-context/src/jvmMain/kotlin/space/kscience/dataforge/context/loggingJvm.kt

@@ -3,11 +3,10 @@ package space.kscience.dataforge.context
 import org.slf4j.LoggerFactory
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.names.Name
-import kotlin.reflect.KClass
 
 public class SlfLogManager : AbstractPlugin(), LogManager {
 
-    override fun log(name: Name, tag: String, body: () -> String) {
+    override fun logger(name: Name): Logger = Logger { tag, body ->
         val logger = LoggerFactory.getLogger("[${context.name}] $name") //KotlinLogging.logger("[${context.name}] $name")
         val message = body.safe
         when (tag) {
@@ -19,14 +18,15 @@ public class SlfLogManager : AbstractPlugin(), LogManager {
         }
     }
 
+    override val defaultLogger: Logger = logger(Name.EMPTY)
+
     override val tag: PluginTag get() = Companion.tag
 
     public companion object : PluginFactory<SlfLogManager> {
-        override fun invoke(meta: Meta, context: Context): SlfLogManager = SlfLogManager()
+        override fun build(context: Context, meta: Meta): SlfLogManager = SlfLogManager()
 
         override val tag: PluginTag = PluginTag(group = PluginTag.DATAFORGE_GROUP, name = "log.kotlinLogging")
-        override val type: KClass<out SlfLogManager> = SlfLogManager::class
     }
 }
 
-internal actual val globalLoggerFactory: PluginFactory<out LogManager> = SlfLogManager
+internal actual fun getGlobalLoggerFactory(): PluginFactory<out LogManager> = SlfLogManager

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

@@ -16,35 +16,32 @@
 
 package space.kscience.dataforge.descriptors
 
-import space.kscience.dataforge.values.ValueType
-import kotlin.reflect.KClass
-
-@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
-)
+//@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

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

@@ -1,30 +1,32 @@
 package space.kscience.dataforge.provider
 
 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.Type
+import space.kscience.dataforge.misc.DfId
+import space.kscience.dataforge.misc.Named
 import space.kscience.dataforge.names.Name
 import kotlin.reflect.KClass
 import kotlin.reflect.full.findAnnotation
 
 
 @DFExperimental
-public val KClass<*>.dfType: String
-    get() = findAnnotation<Type>()?.id ?: simpleName ?: ""
+public val KClass<*>.dfId: String
+    get() = findAnnotation<DfId>()?.id ?: simpleName ?: ""
 
 /**
- * Provide an object with given name inferring target from its type using [Type] annotation
+ * Provide an object with given name inferring target from its type using [DfId] annotation
  */
 @DFExperimental
 public inline fun <reified T : Any> Provider.provideByType(name: String): T? {
-    val target = T::class.dfType
+    val target = T::class.dfId
     return provide(target, name)
 }
 
 @DFExperimental
 public inline fun <reified T : Any> Provider.top(): Map<Name, T> {
-    val target = T::class.dfType
+    val target = T::class.dfId
     return top(target)
 }
 
@@ -33,5 +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.dfType, inherit)
+    gather<T>(T::class.dfId, inherit)
 
+
+@DFExperimental
+public inline fun <reified T : Any> PluginBuilder.provides(items: Map<Name, T>) {
+    provides(T::class.dfId, items)
+}
+
+@DFExperimental
+public inline fun <reified T : Any> PluginBuilder.provides(vararg items: Named) {
+    provides(T::class.dfId, *items)
+}

dataforge-context/src/nativeMain/kotlin/space/kscience/dataforge/context/loggingNative.kt

@@ -1,25 +1,4 @@
 package space.kscience.dataforge.context
 
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.names.Name
-import kotlin.reflect.KClass
 
-
-public class NativeLogManager : AbstractPlugin(), LogManager {
-
-    override fun log(name: Name, tag: String, body: () -> String) {
-        val message: String = body.safe
-        println("[${context.name}] $name: $message")
-    }
-
-    override val tag: PluginTag get() = Companion.tag
-
-    public companion object : PluginFactory<NativeLogManager> {
-        override fun invoke(meta: Meta, context: Context): NativeLogManager = NativeLogManager()
-
-        override val tag: PluginTag = PluginTag(group = PluginTag.DATAFORGE_GROUP, name = "log.native")
-        override val type: KClass<out NativeLogManager> = NativeLogManager::class
-    }
-}
-
-internal actual val globalLoggerFactory: PluginFactory<out LogManager> = NativeLogManager
+internal actual fun getGlobalLoggerFactory(): PluginFactory<out LogManager> = DefaultLogManager

dataforge-data/README.md

@@ -0,0 +1,23 @@
+# Module dataforge-data
+
+
+
+## Usage
+
+## Artifact:
+
+The Maven coordinates of this project are `space.kscience:dataforge-data:0.7.0`.
+
+**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")
+}
+```

dataforge-data/build.gradle.kts

@@ -1,23 +1,18 @@
 plugins {
-    id("ru.mipt.npm.gradle.mpp")
-    id("ru.mipt.npm.gradle.native")
+    id("space.kscience.gradle.mpp")
 }
 
 kscience{
+    jvm()
+    js()
+    native()
     useCoroutines()
-}
-
-kotlin {
-    sourceSets {
-        commonMain{
-            dependencies {
-                api(project(":dataforge-meta"))
-                api(kotlin("reflect"))
-            }
-        }
+    dependencies {
+        api(project(":dataforge-meta"))
+        api(kotlin("reflect"))
     }
 }
 
 readme{
-    maturity = ru.mipt.npm.gradle.Maturity.EXPERIMENTAL
+    maturity = space.kscience.gradle.Maturity.EXPERIMENTAL
 }

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

@@ -0,0 +1,65 @@
+package space.kscience.dataforge.actions
+
+import kotlinx.coroutines.launch
+import space.kscience.dataforge.data.*
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.misc.DFInternal
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.startsWith
+import kotlin.reflect.KType
+
+/**
+ * Remove all values with keys starting with [name]
+ */
+internal fun MutableMap<Name, *>.removeWhatStartsWith(name: Name) {
+    val toRemove = keys.filter { it.startsWith(name) }
+    toRemove.forEach(::remove)
+}
+
+/**
+ * An action that caches results on-demand and recalculates them on source push
+ */
+public abstract class AbstractAction<in T : Any, R : Any>(
+    public val outputType: KType,
+) : Action<T, R> {
+
+    /**
+     * Generate initial content of the output
+     */
+    protected abstract fun DataSetBuilder<R>.generate(
+        data: DataSet<T>,
+        meta: Meta,
+    )
+
+    /**
+     * Update part of the data set when given [updateKey] is triggered by the source
+     */
+    protected open fun DataSourceBuilder<R>.update(
+        dataSet: DataSet<T>,
+        meta: Meta,
+        updateKey: Name,
+    ) {
+        // By default, recalculate the whole dataset
+        generate(dataSet, meta)
+    }
+
+    @OptIn(DFInternal::class)
+    override fun execute(
+        dataSet: DataSet<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)
+        }
+    }
+}

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

@@ -1,6 +1,5 @@
 package space.kscience.dataforge.actions
 
-import kotlinx.coroutines.CoroutineScope
 import space.kscience.dataforge.data.DataSet
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.misc.DFExperimental
@@ -9,13 +8,12 @@ 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> {
+
     /**
-     * Transform the data in the node, producing a new node. By default it is assumed that all calculations are lazy
+     * 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.
-     *
-     * [scope] context used to compute the initial result, also it is used for updates propagation
      */
-    public suspend fun execute(dataSet: DataSet<T>, meta: Meta = Meta.EMPTY, scope: CoroutineScope? = null): DataSet<R>
+    public fun execute(dataSet: DataSet<T>, meta: Meta = Meta.EMPTY): DataSet<R>
 
     public companion object
 }
@@ -26,16 +24,17 @@ public interface Action<in T : Any, out R : Any> {
 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 suspend fun execute(dataSet: DataSet<T>, meta: Meta, scope: CoroutineScope?): DataSet<R> {
-            return action.execute(this@then.execute(dataSet, meta, scope), meta, scope)
-        }
+
+        override fun execute(
+            dataSet: DataSet<T>,
+            meta: Meta,
+        ): DataSet<R> = action.execute(this@then.execute(dataSet, meta), meta)
     }
 }
 
 @DFExperimental
-public suspend fun <T : Any, R : Any> DataSet<T>.transformWith(
-    action: Action<T, R>,
+public operator fun <T : Any, R : Any> Action<T, R>.invoke(
+    dataSet: DataSet<T>,
     meta: Meta = Meta.EMPTY,
-    scope: CoroutineScope? = null,
-): DataSet<R> = action.execute(this, meta, scope)
+): DataSet<R> = execute(dataSet, meta)
 

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

@@ -1,12 +1,8 @@
 package space.kscience.dataforge.actions
 
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.flow.collect
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.launch
 import space.kscience.dataforge.data.*
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
+import space.kscience.dataforge.meta.MutableMeta
 import space.kscience.dataforge.meta.seal
 import space.kscience.dataforge.meta.toMutableMeta
 import space.kscience.dataforge.misc.DFBuilder
@@ -29,65 +25,71 @@ public data class ActionEnv(
  * Action environment
  */
 @DFBuilder
-public class MapActionBuilder<T, R>(public var name: Name, public var meta: MetaBuilder, public val actionMeta: Meta) {
+public class MapActionBuilder<T, R>(
+    public var name: Name,
+    public var meta: MutableMeta,
+    public val actionMeta: Meta,
+    @PublishedApi internal var outputType: KType,
+) {
+
     public lateinit var result: suspend ActionEnv.(T) -> R
 
+    /**
+     * Set unsafe [outputType] for the resulting data. Be sure that it is correct.
+     */
+    public fun <R1 : R> result(outputType: KType, f: suspend ActionEnv.(T) -> R1) {
+        this.outputType = outputType
+        result = f;
+    }
+
     /**
      * Calculate the result of goal
      */
-    public fun result(f: suspend ActionEnv.(T) -> R) {
+    public inline fun <reified R1 : R> result(noinline f: suspend ActionEnv.(T) -> R1) {
+        outputType = typeOf<R1>()
         result = f;
     }
 }
 
 @PublishedApi
-internal class MapAction<in T : Any, out R : Any>(
-    private val outputType: KType,
+internal class MapAction<in T : Any, R : Any>(
+    outputType: KType,
     private val block: MapActionBuilder<T, R>.() -> Unit,
-) : Action<T, R> {
+) : AbstractAction<T, R>(outputType) {
 
-    override suspend fun execute(
-        dataSet: DataSet<T>,
-        meta: Meta,
-        scope: CoroutineScope?,
-    ): DataSet<R> {
-        suspend fun mapOne(data: NamedData<T>): NamedData<R> {
-            // Creating a new environment for action using **old** name, old meta and task meta
-            val env = ActionEnv(data.name, data.meta, meta)
+    private fun DataSetBuilder<R>.mapOne(name: Name, data: Data<T>, meta: Meta) {
+        // Creating a new environment for action using **old** name, old meta and task meta
+        val env = ActionEnv(name, data.meta, meta)
 
-            //applying transformation from builder
-            val builder = MapActionBuilder<T, R>(
-                data.name,
-                data.meta.toMutableMeta(), // using data meta
-                meta
-            ).apply(block)
+        //applying transformation from builder
+        val builder = MapActionBuilder<T, R>(
+            name,
+            data.meta.toMutableMeta(), // using data meta
+            meta,
+            outputType
+        ).apply(block)
 
-            //getting new name
-            val newName = builder.name
+        //getting new name
+        val newName = builder.name
 
-            //getting new meta
-            val newMeta = builder.meta.seal()
+        //getting new meta
+        val newMeta = builder.meta.seal()
 
-            @OptIn(DFInternal::class) val newData = Data(outputType, newMeta, dependencies = listOf(data)) {
-                builder.result(env, data.await())
-            }
-            //setting the data node
-            return newData.named(newName)
+        @OptIn(DFInternal::class)
+        val newData = Data(builder.outputType, newMeta, dependencies = listOf(data)) {
+            builder.result(env, data.await())
         }
+        //setting the data node
+        data(newName, newData)
+    }
 
-        val flow = dataSet.flow().map(::mapOne)
+    override fun DataSetBuilder<R>.generate(data: DataSet<T>, meta: Meta) {
+        data.forEach { mapOne(it.name, it.data, meta) }
+    }
 
-        return ActiveDataTree(outputType) {
-            populate(flow)
-            scope?.launch {
-                dataSet.updates.collect { name ->
-                    //clear old nodes
-                    remove(name)
-                    //collect new items
-                    populate(dataSet.flowChildren(name).map(::mapOne))
-                }
-            }
-        }
+    override fun DataSourceBuilder<R>.update(dataSet: DataSet<T>, meta: Meta, updateKey: Name) {
+        remove(updateKey)
+        dataSet[updateKey]?.let { mapOne(updateKey, it, meta) }
     }
 }
 

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

@@ -1,28 +1,34 @@
 package space.kscience.dataforge.actions
 
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.flow.fold
 import space.kscience.dataforge.data.*
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
+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.names.Name
-import space.kscience.dataforge.names.toName
+import space.kscience.dataforge.names.parseAsName
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
 
-public class JoinGroup<T : Any, R : Any>(public var name: String, internal val set: DataSet<T>) {
+public class JoinGroup<T : Any, R : Any>(
+    public var name: String,
+    internal val set: DataSet<T>,
+    @PublishedApi internal var outputType: KType,
+) {
 
-    public var meta: MetaBuilder = MetaBuilder()
+    public var meta: MutableMeta = MutableMeta()
 
-    public lateinit var result: suspend ActionEnv.(Map<Name, T>) -> R
+    public lateinit var result: suspend ActionEnv.(Map<Name, ValueWithMeta<T>>) -> R
 
-    public fun result(f: suspend ActionEnv.(Map<Name, T>) -> R) {
+    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) {
+        outputType = typeOf<R1>()
         this.result = f;
     }
 
@@ -30,31 +36,30 @@ public class JoinGroup<T : Any, R : Any>(public var name: String, internal val s
 
 @DFBuilder
 public class ReduceGroupBuilder<T : Any, R : Any>(
-    private val inputType: KType,
-    private val scope: CoroutineScope,
     public val actionMeta: Meta,
+    private val outputType: KType,
 ) {
-    private val groupRules: MutableList<suspend (DataSet<T>) -> List<JoinGroup<T, R>>> = ArrayList();
+    private val groupRules: MutableList<(DataSet<T>) -> List<JoinGroup<T, R>>> = ArrayList();
 
     /**
      * introduce grouping by meta value
      */
     public fun byValue(tag: String, defaultTag: String = "@default", action: JoinGroup<T, R>.() -> Unit) {
         groupRules += { node ->
-            GroupRule.byMetaValue(scope, tag, defaultTag).gather(node).map {
-                JoinGroup<T, R>(it.key, it.value).apply(action)
+            GroupRule.byMetaValue(tag, defaultTag).gather(node).map {
+                JoinGroup<T, R>(it.key, it.value, outputType).apply(action)
             }
         }
     }
 
     public fun group(
         groupName: String,
-        filter: suspend (Name, Data<T>) -> Boolean,
+        predicate: (Name, Meta) -> Boolean,
         action: JoinGroup<T, R>.() -> Unit,
     ) {
         groupRules += { source ->
             listOf(
-                JoinGroup<T, R>(groupName, source.filter(filter)).apply(action)
+                JoinGroup<T, R>(groupName, source.filter(predicate), outputType).apply(action)
             )
         }
     }
@@ -62,30 +67,27 @@ public class ReduceGroupBuilder<T : Any, R : Any>(
     /**
      * Apply transformation to the whole node
      */
-    public fun result(resultName: String, f: suspend ActionEnv.(Map<Name, T>) -> R) {
+    public fun result(resultName: String, f: suspend ActionEnv.(Map<Name,  ValueWithMeta<T>>) -> R) {
         groupRules += { node ->
-            listOf(JoinGroup<T, R>(resultName, node).apply { result(f) })
+            listOf(JoinGroup<T, R>(resultName, node, outputType).apply { result(outputType, f) })
         }
     }
 
-    internal suspend fun buildGroups(input: DataSet<T>): List<JoinGroup<T, R>> {
-        return groupRules.flatMap { it.invoke(input) }
-    }
+    internal fun buildGroups(input: DataSet<T>): List<JoinGroup<T, R>> =
+        groupRules.flatMap { it.invoke(input) }
 
 }
 
 @PublishedApi
 internal class ReduceAction<T : Any, R : Any>(
-    private val inputType: KType,
     outputType: KType,
     private val action: ReduceGroupBuilder<T, R>.() -> Unit,
-) : CachingAction<T, R>(outputType) {
-    //TODO optimize reduction. Currently the whole action recalculates on push
+) : AbstractAction<T, R>(outputType) {
+    //TODO optimize reduction. Currently, the whole action recalculates on push
 
-
-    override fun CoroutineScope.transform(set: DataSet<T>, meta: Meta, key: Name): Flow<NamedData<R>> = flow {
-        ReduceGroupBuilder<T, R>(inputType, this@transform, meta).apply(action).buildGroups(set).forEach { group ->
-            val dataFlow: Map<Name, Data<T>> = group.set.flow().fold(HashMap()) { acc, value ->
+    override fun DataSetBuilder<R>.generate(data: DataSet<T>, meta: Meta) {
+        ReduceGroupBuilder<T, R>(meta, outputType).apply(action).buildGroups(data).forEach { group ->
+            val dataFlow: Map<Name, Data<T>> = group.set.asSequence().fold(HashMap()) { acc, value ->
                 acc.apply {
                     acc[value.name] = value.data
                 }
@@ -95,13 +97,13 @@ internal class ReduceAction<T : Any, R : Any>(
 
             val groupMeta = group.meta
 
-            val env = ActionEnv(groupName.toName(), groupMeta, meta)
+            val env = ActionEnv(groupName.parseAsName(), groupMeta, meta)
             @OptIn(DFInternal::class) val res: Data<R> = dataFlow.reduceToData(
-                outputType,
+                group.outputType,
                 meta = groupMeta
             ) { group.result.invoke(env, it) }
 
-            emit(res.named(env.name))
+            data(env.name, res)
         }
     }
 }
@@ -110,7 +112,6 @@ internal class ReduceAction<T : Any, R : Any>(
  * A one-to-one mapping action
  */
 @DFExperimental
-@Suppress("FunctionName")
 public inline fun <reified T : Any, reified R : Any> Action.Companion.reduce(
     noinline builder: ReduceGroupBuilder<T, R>.() -> Unit,
-): Action<T, R> = ReduceAction(typeOf<T>(), typeOf<R>(), builder)
+): Action<T, R> = ReduceAction(typeOf<R>(), builder)

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

@@ -1,18 +1,13 @@
 package space.kscience.dataforge.actions
 
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.FlowPreview
-import kotlinx.coroutines.flow.*
-import kotlinx.coroutines.launch
 import space.kscience.dataforge.data.*
 import space.kscience.dataforge.meta.Laminate
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
+import space.kscience.dataforge.meta.MutableMeta
 import space.kscience.dataforge.meta.toMutableMeta
 import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.misc.DFInternal
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.toName
+import space.kscience.dataforge.names.parseAsName
 import kotlin.collections.set
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
@@ -20,10 +15,15 @@ import kotlin.reflect.typeOf
 
 public class SplitBuilder<T : Any, R : Any>(public val name: Name, public val meta: Meta) {
 
-    public class FragmentRule<T : Any, R : Any>(public val name: Name, public var meta: MetaBuilder) {
+    public class FragmentRule<T : Any, R : Any>(
+        public val name: Name,
+        public var meta: MutableMeta,
+        @PublishedApi internal var outputType: KType,
+    ) {
         public lateinit var result: suspend (T) -> R
 
-        public fun result(f: suspend (T) -> R) {
+        public inline fun <reified R1 : R> result(noinline f: suspend (T) -> R1) {
+            this.outputType = typeOf<R1>()
             result = f;
         }
     }
@@ -36,7 +36,7 @@ public class SplitBuilder<T : Any, R : Any>(public val name: Name, public val me
      * @param rule the rule to transform fragment name and meta using
      */
     public fun fragment(name: String, rule: FragmentRule<T, R>.() -> Unit) {
-        fragments[name.toName()] = rule
+        fragments[name.parseAsName()] = rule
     }
 }
 
@@ -45,52 +45,48 @@ public class SplitBuilder<T : Any, R : Any>(public val name: Name, public val me
  */
 @PublishedApi
 internal class SplitAction<T : Any, R : Any>(
-    private val outputType: KType,
+    outputType: KType,
     private val action: SplitBuilder<T, R>.() -> Unit,
-) : Action<T, R> {
+) : AbstractAction<T, R>(outputType) {
 
-    @OptIn(FlowPreview::class)
-    override suspend fun execute(
-        dataSet: DataSet<T>,
-        meta: Meta,
-        scope: CoroutineScope?,
-    ): DataSet<R> {
+    private fun DataSetBuilder<R>.splitOne(name: Name, data: Data<T>, meta: Meta) {
+        val laminate = Laminate(data.meta, meta)
 
-        suspend fun splitOne(data: NamedData<T>): Flow<NamedData<R>> {
-            val laminate = Laminate(data.meta, meta)
-
-            val split = SplitBuilder<T, R>(data.name, data.meta).apply(action)
+        val split = SplitBuilder<T, R>(name, data.meta).apply(action)
 
 
-            // apply individual fragment rules to result
-            return split.fragments.entries.asFlow().map { (fragmentName, rule) ->
-                val env = SplitBuilder.FragmentRule<T, R>(fragmentName, laminate.toMutableMeta()).apply(rule)
-                //data.map<R>(outputType, meta = env.meta) { env.result(it) }.named(fragmentName)
-                @OptIn(DFInternal::class) Data(outputType, meta = env.meta, dependencies = listOf(data)) {
+        // apply individual fragment rules to result
+        split.fragments.forEach { (fragmentName, rule) ->
+            val env = SplitBuilder.FragmentRule<T, R>(
+                fragmentName,
+                laminate.toMutableMeta(),
+                outputType
+            ).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())
-                }.named(fragmentName)
-            }
-        }
-
-        return ActiveDataTree<R>(outputType) {
-            populate(dataSet.flow().flatMapConcat(transform = ::splitOne))
-            scope?.launch {
-                dataSet.updates.collect { name ->
-                    //clear old nodes
-                    remove(name)
-                    //collect new items
-                    populate(dataSet.flowChildren(name).flatMapConcat(transform = ::splitOne))
                 }
-            }
+            )
         }
     }
+
+    override fun DataSetBuilder<R>.generate(data: DataSet<T>, meta: Meta) {
+        data.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) }
+    }
 }
 
 /**
  * Action that splits each incoming element into a number of fragments defined in builder
  */
 @DFExperimental
-@Suppress("FunctionName")
 public inline fun <T : Any, reified R : Any> Action.Companion.split(
     noinline builder: SplitBuilder<T, R>.() -> Unit,
 ): Action<T, R> = SplitAction(typeOf<R>(), builder)

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

@@ -1,118 +0,0 @@
-package space.kscience.dataforge.data
-
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.flow.*
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.sync.Mutex
-import kotlinx.coroutines.sync.withLock
-import space.kscience.dataforge.meta.*
-import space.kscience.dataforge.names.*
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
-
-/**
- * A mutable [DataTree.Companion.active]. It
- */
-public class ActiveDataTree<T : Any>(
-    override val dataType: KType,
-) : DataTree<T>, DataSetBuilder<T>, ActiveDataSet<T> {
-    private val mutex = Mutex()
-    private val treeItems = HashMap<NameToken, DataTreeItem<T>>()
-
-    override suspend fun items(): Map<NameToken, DataTreeItem<T>> = mutex.withLock {
-        treeItems.filter { !it.key.body.startsWith("@") }
-    }
-
-    private val _updates = MutableSharedFlow<Name>()
-
-    override val updates: Flow<Name>
-        get() = _updates
-
-    private suspend fun remove(token: NameToken) {
-        mutex.withLock {
-            if (treeItems.remove(token) != null) {
-                _updates.emit(token.asName())
-            }
-        }
-    }
-
-    override suspend fun remove(name: Name) {
-        if (name.isEmpty()) error("Can't remove the root node")
-        (getItem(name.cutLast()).tree as? ActiveDataTree)?.remove(name.lastOrNull()!!)
-    }
-
-    private suspend fun set(token: NameToken, data: Data<T>) {
-        mutex.withLock {
-            treeItems[token] = DataTreeItem.Leaf(data)
-        }
-    }
-
-    private suspend fun getOrCreateNode(token: NameToken): ActiveDataTree<T> =
-        (treeItems[token] as? DataTreeItem.Node<T>)?.tree as? ActiveDataTree<T>
-            ?: ActiveDataTree<T>(dataType).also {
-                mutex.withLock {
-                    treeItems[token] = DataTreeItem.Node(it)
-                }
-            }
-
-    private suspend fun getOrCreateNode(name: Name): ActiveDataTree<T> {
-        return when (name.length) {
-            0 -> this
-            1 -> getOrCreateNode(name.firstOrNull()!!)
-            else -> getOrCreateNode(name.firstOrNull()!!).getOrCreateNode(name.cutFirst())
-        }
-    }
-
-    override suspend fun emit(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)
-            }
-        }
-        _updates.emit(name)
-    }
-
-    /**
-     * Copy given data set and mirror its changes to this [ActiveDataTree] in [this@setAndObserve]. Returns an update [Job]
-     */
-    public fun CoroutineScope.setAndObserve(name: Name, dataSet: DataSet<T>): Job = launch {
-        emit(name, dataSet)
-        dataSet.updates.collect { nameInBranch ->
-            emit(name + nameInBranch, dataSet.getData(nameInBranch))
-        }
-    }
-}
-
-/**
- * Create a dynamic tree. Initial data is placed synchronously. Updates are propagated via [updatesScope]
- */
-@Suppress("FunctionName")
-public suspend fun <T : Any> ActiveDataTree(
-    type: KType,
-    block: suspend ActiveDataTree<T>.() -> Unit,
-): ActiveDataTree<T> {
-    val tree = ActiveDataTree<T>(type)
-    tree.block()
-    return tree
-}
-
-@Suppress("FunctionName")
-public suspend inline fun <reified T : Any> ActiveDataTree(
-    crossinline block: suspend ActiveDataTree<T>.() -> Unit,
-): ActiveDataTree<T> = ActiveDataTree<T>(typeOf<T>()).apply { block() }
-
-
-public suspend inline fun <reified T : Any> ActiveDataTree<T>.emit(
-    name: Name,
-    noinline block: suspend ActiveDataTree<T>.() -> Unit,
-): Unit = emit(name, ActiveDataTree(typeOf<T>(), block))
-
-public suspend inline fun <reified T : Any> ActiveDataTree<T>.emit(
-    name: String,
-    noinline block: suspend ActiveDataTree<T>.() -> Unit,
-): Unit = emit(name.toName(), ActiveDataTree(typeOf<T>(), block))

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

@@ -1,52 +0,0 @@
-package space.kscience.dataforge.data
-
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.coroutineScope
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.collect
-import space.kscience.dataforge.actions.Action
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.startsWith
-import kotlin.reflect.KType
-
-/**
- * Remove all values with keys starting with [name]
- */
-internal fun MutableMap<Name, *>.removeWhatStartsWith(name: Name) {
-    val toRemove = keys.filter { it.startsWith(name) }
-    toRemove.forEach(::remove)
-}
-
-/**
- * An action that caches results on-demand and recalculates them on source push
- */
-public abstract class CachingAction<in T : Any, out R : Any>(
-    public val outputType: KType,
-) : Action<T, R> {
-
-    protected abstract fun CoroutineScope.transform(
-        set: DataSet<T>,
-        meta: Meta,
-        key: Name = Name.EMPTY,
-    ): Flow<NamedData<R>>
-
-    override suspend fun execute(
-        dataSet: DataSet<T>,
-        meta: Meta,
-        scope: CoroutineScope?,
-    ): DataSet<R> = ActiveDataTree<R>(outputType) {
-        coroutineScope {
-            populate(transform(dataSet, meta))
-        }
-        scope?.let {
-            dataSet.updates.collect {
-                //clear old nodes
-                remove(it)
-                //collect new items
-                populate(scope.transform(dataSet, meta, it))
-                //FIXME if the target is data, updates are fired twice
-            }
-        }
-    }
-}

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

@@ -48,9 +48,9 @@ public val CoroutineScope.monitor: CoroutineMonitor? get() = coroutineContext.mo
 public val Job.dependencies: Collection<Job> get() = this[Dependencies]?.values ?: emptyList()
 
 @DFExperimental
-public val Job.totalWork: Double get() = dependencies.sumByDouble { totalWork } + (monitor?.totalWork ?: 0.0)
+public val Job.totalWork: Double get() = dependencies.sumOf { totalWork } + (monitor?.totalWork ?: 0.0)
 @DFExperimental
-public val Job.workDone: Double get() = dependencies.sumByDouble { workDone } + (monitor?.workDone ?: 0.0)
+public val Job.workDone: Double get() = dependencies.sumOf { workDone } + (monitor?.workDone ?: 0.0)
 @DFExperimental
 public val Job.status: String get() = monitor?.status ?: ""
 @DFExperimental

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

@@ -5,7 +5,7 @@ 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.Type
+import space.kscience.dataforge.misc.DfId
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.EmptyCoroutineContext
 import kotlin.reflect.KType
@@ -14,8 +14,8 @@ import kotlin.reflect.typeOf
 /**
  * A data element characterized by its meta
  */
-@Type(Data.TYPE)
-public interface Data<out T : Any> : Goal<T>, MetaRepr {
+@DfId(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.
      */
@@ -49,6 +49,7 @@ public interface Data<out T : Any> : 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
             override val meta: Meta = meta
@@ -72,7 +73,7 @@ private class LazyData<T : Any>(
     override val type: KType,
     override val meta: Meta = Meta.EMPTY,
     additionalContext: CoroutineContext = EmptyCoroutineContext,
-    dependencies: Collection<Data<*>> = emptyList(),
+    dependencies: Collection<Goal<*>> = emptyList(),
     block: suspend () -> T,
 ) : Data<T>, LazyGoal<T>(additionalContext, dependencies, block)
 
@@ -82,13 +83,17 @@ public class StaticData<T : Any>(
     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> =
+    StaticData(typeOf<T>(), value, meta)
+
 @Suppress("FunctionName")
 @DFInternal
 public fun <T : Any> Data(
     type: KType,
     meta: Meta = Meta.EMPTY,
     context: CoroutineContext = EmptyCoroutineContext,
-    dependencies: Collection<Data<*>> = emptyList(),
+    dependencies: Collection<Goal<*>> = emptyList(),
     block: suspend () -> T,
 ): Data<T> = LazyData(type, meta, context, dependencies, block)
 
@@ -97,6 +102,6 @@ public fun <T : Any> Data(
 public inline fun <reified T : Any> Data(
     meta: Meta = Meta.EMPTY,
     context: CoroutineContext = EmptyCoroutineContext,
-    dependencies: Collection<Data<*>> = emptyList(),
+    dependencies: Collection<Goal<*>> = emptyList(),
     noinline block: suspend () -> T,
 ): Data<T> = Data(typeOf<T>(), meta, context, dependencies, block)

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

@@ -1,11 +1,15 @@
 package space.kscience.dataforge.data
 
 import kotlinx.coroutines.*
-import kotlinx.coroutines.flow.*
+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.meta.set
-import space.kscience.dataforge.names.*
+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> {
@@ -16,24 +20,19 @@ public interface DataSet<out T : Any> {
     public val dataType: KType
 
     /**
-     * Traverse this provider or its child. The order is not guaranteed.
-     * [root] points to a root name for traversal. If it is empty, traverse this source, if it points to a [Data],
-     * return flow, that contains single [Data], if it points to a node with children, return children.
+     * Meta-data associated with this node. If no meta is provided, returns [Meta.EMPTY].
      */
-    public fun flow(): Flow<NamedData<T>>
+    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 suspend fun getData(name: Name): Data<T>?
-
-    /**
-     * Get a snapshot of names of children of given node. Empty if node does not exist or is a leaf.
-     *
-     * By default traverses the whole tree. Could be optimized in descendants
-     */
-    public suspend fun listChildren(prefix: Name = Name.EMPTY): List<Name> =
-        flow().map { it.name }.filter { it.startsWith(prefix) && (it.length == prefix.length + 1) }.toList()
+    public operator fun get(name: Name): Data<T>?
 
     public companion object {
         public val META_KEY: Name = "@meta".asName()
@@ -43,17 +42,35 @@ public interface DataSet<out T : Any> {
          */
         public val EMPTY: DataSet<Nothing> = object : DataSet<Nothing> {
             override val dataType: KType = TYPE_OF_NOTHING
+            override val meta: Meta get() = Meta.EMPTY
 
-            private val nothing: Nothing get() = error("this is nothing")
+            override fun iterator(): Iterator<NamedData<Nothing>> = emptySequence<NamedData<Nothing>>().iterator()
 
-            override fun flow(): Flow<NamedData<Nothing>> = emptyFlow()
-
-            override suspend fun getData(name: Name): Data<Nothing>? = null
+            override fun get(name: Name): Data<Nothing>? = null
         }
     }
 }
 
-public interface ActiveDataSet<T : Any> : DataSet<T> {
+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
@@ -61,30 +78,38 @@ public interface ActiveDataSet<T : Any> : DataSet<T> {
      *
      */
     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 ActiveDataSet) updates else emptyFlow()
-
-/**
- * Flow all data nodes with names starting with [branchName]
- */
-public fun <T : Any> DataSet<T>.flowChildren(branchName: Name): Flow<NamedData<T>> = this@flowChildren.flow().filter {
-    it.name.startsWith(branchName)
-}
+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 {
-    flow().map {
+    asIterable().map {
         it.launch(this@launch)
-    }.toList().joinAll()
+    }.joinAll()
 }
 
-public suspend fun <T : Any> DataSet<T>.join(): Unit = coroutineScope { startAll(this).join() }
+public suspend fun <T : Any> DataSet<T>.computeAndJoinAll(): Unit = coroutineScope { startAll(this).join() }
 
-public suspend fun DataSet<*>.toMeta(): Meta = Meta {
-    flow().collect {
+public fun DataSet<*>.toMeta(): Meta = Meta {
+    forEach {
         if (it.name.endsWith(DataSet.META_KEY)) {
             set(it.name, it.meta)
         } else {
@@ -96,4 +121,4 @@ public suspend fun DataSet<*>.toMeta(): Meta = Meta {
     }
 }
 
-public val <T : Any> DataSet<T>.updatesWithData: Flow<NamedData<T>> get() = updates.mapNotNull { getData(it)?.named(it) }
+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

@@ -1,14 +1,11 @@
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.coroutineScope
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.collect
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
+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 space.kscience.dataforge.names.toName
 import kotlin.reflect.KType
 
 public interface DataSetBuilder<in T : Any> {
@@ -17,129 +14,152 @@ public interface DataSetBuilder<in T : Any> {
     /**
      * Remove all data items starting with [name]
      */
-    public suspend fun remove(name: Name)
+    public fun remove(name: Name)
 
-    public suspend fun emit(name: Name, data: Data<T>?)
+    public fun data(name: Name, data: Data<T>?)
 
     /**
      * Set a current state of given [dataSet] into a branch [name]. Does not propagate updates
      */
-    public suspend fun emit(name: Name, dataSet: DataSet<T>) {
+    public fun node(name: Name, dataSet: DataSet<T>) {
         //remove previous items
         if (name != Name.EMPTY) {
             remove(name)
         }
 
         //Set new items
-        dataSet.flow().collect {
-            emit(name + it.name, it.data)
+        dataSet.forEach {
+            data(name + it.name, it.data)
         }
     }
 
     /**
-     * Append data to node
+     * Set meta for the given node
      */
-    public suspend infix fun String.put(data: Data<T>): Unit = emit(toName(), data)
+    public fun meta(name: Name, meta: Meta)
 
-    /**
-     * Append node
-     */
-    public suspend infix fun String.put(dataSet: DataSet<T>): Unit = emit(toName(), dataSet)
-
-    /**
-     * Build and append node
-     */
-    public suspend infix fun String.put(block: suspend DataSetBuilder<T>.() -> Unit): Unit = emit(toName(), block)
 }
 
-private class SubSetBuilder<in T : Any>(
+/**
+ * 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 suspend fun remove(name: Name) {
+    override fun remove(name: Name) {
         parent.remove(branch + name)
     }
 
-    override suspend fun emit(name: Name, data: Data<T>?) {
-        parent.emit(branch + name, data)
+    override fun data(name: Name, data: Data<T>?) {
+        parent.data(branch + name, data)
     }
 
-    override suspend fun emit(name: Name, dataSet: DataSet<T>) {
-        parent.emit(branch + name, dataSet)
+    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 suspend fun <T : Any> DataSetBuilder<T>.emit(name: Name, block: suspend DataSetBuilder<T>.() -> Unit) {
-    SubSetBuilder(this, name).apply { block() }
+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 suspend fun <T : Any> DataSetBuilder<T>.emit(name: String, data: Data<T>) {
-    emit(name.toName(), data)
+public fun <T : Any> DataSetBuilder<T>.data(name: String, value: Data<T>) {
+    data(Name.parse(name), value)
 }
 
-public suspend fun <T : Any> DataSetBuilder<T>.emit(name: String, set: DataSet<T>) {
-    this.emit(name.toName(), set)
+public fun <T : Any> DataSetBuilder<T>.node(name: String, set: DataSet<T>) {
+    node(Name.parse(name), set)
 }
 
-public suspend fun <T : Any> DataSetBuilder<T>.emit(name: String, block: suspend DataSetBuilder<T>.() -> Unit): Unit =
-    this@emit.emit(name.toName(), block)
+public inline fun <T : Any> DataSetBuilder<T>.node(
+    name: String,
+    crossinline block: DataSetBuilder<T>.() -> Unit,
+): Unit = node(Name.parse(name), block)
 
-public suspend fun <T : Any> DataSetBuilder<T>.emit(data: NamedData<T>) {
-    emit(data.name, data.data)
+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 suspend inline fun <reified T : Any> DataSetBuilder<T>.produce(
+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)
-    emit(name, data)
+    data(name, data)
 }
 
-public suspend inline fun <reified T : Any> DataSetBuilder<T>.produce(
+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)
-    emit(name, data)
+    data(name, data)
 }
 
 /**
  * Emit a static data with the fixed value
  */
-public suspend inline fun <reified T : Any> DataSetBuilder<T>.static(name: String, data: T, meta: Meta = Meta.EMPTY): Unit =
-    emit(name, Data.static(data, meta))
-
-public suspend inline fun <reified T : Any> DataSetBuilder<T>.static(name: Name, data: T, meta: Meta = Meta.EMPTY): Unit =
-    emit(name, Data.static(data, meta))
-
-public suspend inline fun <reified T : Any> DataSetBuilder<T>.static(
+public inline fun <reified T : Any> DataSetBuilder<T>.static(
     name: String,
     data: T,
-    metaBuilder: MetaBuilder.() -> Unit,
-): Unit = emit(name.toName(), Data.static(data, Meta(metaBuilder)))
+    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 suspend fun <T : Any> DataSetBuilder<T>.populate(tree: DataSet<T>): Unit = coroutineScope {
-    tree.flow().collect {
+public fun <T : Any> DataSetBuilder<T>.populateFrom(tree: DataSet<T>): Unit {
+    tree.forEach {
         //TODO check if the place is occupied
-        emit(it.name, it.data)
+        data(it.name, it.data)
     }
 }
 
-public suspend fun <T : Any> DataSetBuilder<T>.populate(flow: Flow<NamedData<T>>) {
-    flow.collect {
-        emit(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/DataTree.kt

@@ -1,18 +1,25 @@
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.emitAll
-import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.flow.map
-import space.kscience.dataforge.misc.Type
+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 class Node<out T : Any>(public val tree: DataTree<T>) : DataTreeItem<T>()
-    public class Leaf<out T : Any>(public val data: Data<T>) : DataTreeItem<T>()
+
+    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
@@ -24,63 +31,79 @@ public val <T : Any> DataTreeItem<T>.type: KType
 /**
  * A tree-like [DataSet] grouped into the node. All data inside the node must inherit its type
  */
-@Type(DataTree.TYPE)
+@DfId(DataTree.TYPE)
 public interface DataTree<out T : Any> : DataSet<T> {
 
     /**
-     * Children items of this [DataTree] provided asynchronously
+     * Top-level children items of this [DataTree]
      */
-    public suspend fun items(): Map<NameToken, DataTreeItem<T>>
+    public val items: Map<NameToken, DataTreeItem<T>>
 
-    override fun flow(): Flow<NamedData<T>> = flow {
-        items().forEach { (token, childItem: DataTreeItem<T>) ->
-            if(!token.body.startsWith("@")) {
+    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 -> emit(childItem.data.named(token.asName()))
-                    is DataTreeItem.Node -> emitAll(childItem.tree.flow().map { it.named(token + it.name) })
+                    is DataTreeItem.Leaf -> yield(childItem.data.named(token.asName()))
+                    is DataTreeItem.Node -> yieldAll(childItem.tree.asSequence().map { it.named(token + it.name) })
                 }
             }
         }
     }
 
-    override suspend fun listChildren(prefix: Name): List<Name> =
-        getItem(prefix).tree?.items()?.keys?.map { prefix + it } ?: emptyList()
-
-    override suspend fun getData(name: Name): Data<T>? = when (name.length) {
+    override fun get(name: Name): Data<T>? = when (name.length) {
         0 -> null
-        1 -> items()[name.firstOrNull()!!].data
-        else -> items()[name.firstOrNull()!!].tree?.getData(name.cutFirst())
+        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 suspend fun <T: Any> DataSet<T>.getData(name: String): Data<T>? = getData(name.toName())
+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 suspend fun <T : Any> DataTree<T>.getItem(name: Name): DataTreeItem<T>? = when (name.length) {
+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())
+    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
 
 /**
- * Flow of all children including nodes
+ * A [Sequence] of all children including nodes
  */
-public fun <T : Any> DataTree<T>.itemFlow(): Flow<Pair<Name, DataTreeItem<T>>> = flow {
-    items().forEach { (head, item) ->
-        emit(head.asName() to item)
+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.itemFlow()
+            val subSequence = item.tree.traverseItems()
                 .map { (name, data) -> (head.asName() + name) to data }
-            emitAll(subSequence)
+            yieldAll(subSequence)
         }
     }
 }
@@ -89,8 +112,8 @@ public fun <T : Any> DataTree<T>.itemFlow(): Flow<Pair<Name, DataTreeItem<T>>> =
  * 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]
  */
-public fun <T : Any> DataTree<T>.branch(branchName: Name): DataTree<T> = object : DataTree<T> {
-    override val dataType: KType get() = this@branch.dataType
+@OptIn(DFInternal::class)
+public fun <T : Any> DataTree<T>.branch(branchName: Name): DataTree<T> =
+    getItem(branchName)?.tree ?: DataTree.emptyWithType(dataType)
 
-    override suspend fun items(): Map<NameToken, DataTreeItem<T>> = getItem(branchName).tree?.items() ?: emptyMap()
-}
+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

@@ -0,0 +1,127 @@
+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

@@ -67,7 +67,7 @@ public open class LazyGoal<T>(
      * If [GoalExecutionRestriction] is present in the [coroutineScope] context, the call could produce a error a warning
      * depending on the settings.
      */
-    @DFExperimental
+    @OptIn(DFExperimental::class)
     override fun async(coroutineScope: CoroutineScope): Deferred<T> {
         val log = coroutineScope.coroutineContext[GoalLogger]
         // Check if context restricts goal computation

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

@@ -3,11 +3,25 @@ package space.kscience.dataforge.data
 import kotlin.coroutines.CoroutineContext
 
 public enum class GoalExecutionRestrictionPolicy {
+    /**
+     * Allow eager execution
+     */
     NONE,
+
+    /**
+     * Give warning on eager execution
+     */
     WARNING,
+
+    /**
+     * Throw error on eager execution
+     */
     ERROR
 }
 
+/**
+ * A special coroutine context key that allows or disallows goal execution during configuration time (eager execution).
+ */
 public class GoalExecutionRestriction(
     public val policy: GoalExecutionRestrictionPolicy = GoalExecutionRestrictionPolicy.ERROR,
 ) : CoroutineContext.Element {

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

@@ -2,6 +2,9 @@ package space.kscience.dataforge.data
 
 import kotlin.coroutines.CoroutineContext
 
+/**
+ * Coroutine context element that provides logging capabilities
+ */
 public interface GoalLogger : CoroutineContext.Element {
     override val key: CoroutineContext.Key<*> get() = GoalLogger
 

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

@@ -15,14 +15,13 @@
  */
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
 import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.string
+import space.kscience.dataforge.misc.DFInternal
 
 public interface GroupRule {
-    public suspend fun <T : Any> gather(set: DataSet<T>): Map<String, DataSet<T>>
+    public fun <T : Any> gather(set: DataSet<T>): Map<String, DataSet<T>>
 
     public companion object {
         /**
@@ -33,30 +32,45 @@ public interface GroupRule {
          * @param defaultTagValue
          * @return
          */
+        @OptIn(DFInternal::class)
         public fun byMetaValue(
-            scope: CoroutineScope,
             key: String,
             defaultTagValue: String,
         ): GroupRule = object : GroupRule {
 
-            override suspend fun <T : Any> gather(
+            override fun <T : Any> gather(
                 set: DataSet<T>,
             ): Map<String, DataSet<T>> {
-                val map = HashMap<String, ActiveDataTree<T>>()
+                val map = HashMap<String, DataSet<T>>()
 
-                set.flow().collect { data ->
-                    val tagValue = data.meta[key]?.string ?: defaultTagValue
-                    map.getOrPut(tagValue) { ActiveDataTree(set.dataType) }.emit(data.name, data.data)
-                }
+                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)
 
-                scope.launch {
-                    set.updates.collect { name ->
-                        val data = set.getData(name)
-                        val tagValue = data?.meta[key].string ?: defaultTagValue
-                        map.getOrPut(tagValue) { ActiveDataTree(set.dataType) }.emit(name, 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)
                     }
                 }
 
+
                 return map
             }
         }

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

@@ -9,6 +9,9 @@ public interface NamedData<out T : Any> : Named, Data<T> {
     public val data: Data<T>
 }
 
+public operator fun NamedData<*>.component1(): Name = name
+public operator fun <T: Any> NamedData<T>.component2(): Data<T> = data
+
 private class NamedDataImpl<out T : Any>(
     override val name: Name,
     override val data: Data<T>,

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

@@ -1,7 +1,6 @@
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.coroutineScope
-import kotlinx.coroutines.flow.collect
+import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.misc.DFExperimental
 import space.kscience.dataforge.names.*
 import kotlin.reflect.KType
@@ -12,15 +11,16 @@ internal class StaticDataTree<T : Any>(
     override val dataType: KType,
 ) : DataSetBuilder<T>, DataTree<T> {
 
-    private val items: MutableMap<NameToken, DataTreeItem<T>> = HashMap()
+    private val _items: MutableMap<NameToken, DataTreeItem<T>> = HashMap()
 
-    override suspend fun items(): Map<NameToken, DataTreeItem<T>> = items.filter { !it.key.body.startsWith("@") }
+    override val items: Map<NameToken, DataTreeItem<T>>
+        get() = _items.filter { !it.key.body.startsWith("@") }
 
-    override suspend fun remove(name: Name) {
+    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())
+            1 -> _items.remove(name.firstOrNull()!!)
+            else -> (_items[name.firstOrNull()!!].tree as? StaticDataTree<T>)?.remove(name.cutFirst())
         }
     }
 
@@ -28,51 +28,55 @@ internal class StaticDataTree<T : Any>(
         0 -> this
         1 -> {
             val itemName = name.firstOrNull()!!
-            (items[itemName].tree as? StaticDataTree<T>) ?: StaticDataTree<T>(dataType).also {
-                items[itemName] = DataTreeItem.Node(it)
+            (_items[itemName].tree as? StaticDataTree<T>) ?: StaticDataTree<T>(dataType).also {
+                _items[itemName] = DataTreeItem.Node(it)
             }
         }
         else -> getOrCreateNode(name.cutLast()).getOrCreateNode(name.lastOrNull()!!.asName())
     }
 
-    private suspend fun set(name: Name, item: DataTreeItem<T>?) {
+    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
+            getOrCreateNode(name.cutLast())._items[name.lastOrNull()!!] = item
         }
     }
 
-    override suspend fun emit(name: Name, data: Data<T>?) {
+    override fun data(name: Name, data: Data<T>?) {
         set(name, data?.let { DataTreeItem.Leaf(it) })
     }
 
-    override suspend fun emit(name: Name, dataSet: DataSet<T>) {
+    override fun node(name: Name, dataSet: DataSet<T>) {
         if (dataSet is StaticDataTree) {
             set(name, DataTreeItem.Node(dataSet))
         } else {
-            coroutineScope {
-                dataSet.flow().collect {
-                    emit(name + it.name, it.data)
-                }
+            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 suspend fun <T : Any> DataTree(
+public inline fun <T : Any> DataTree(
     dataType: KType,
-    block: suspend DataSetBuilder<T>.() -> Unit,
+    block: DataSetBuilder<T>.() -> Unit,
 ): DataTree<T> = StaticDataTree<T>(dataType).apply { block() }
 
 @Suppress("FunctionName")
-public suspend inline fun <reified T : Any> DataTree(
-    noinline block: suspend DataSetBuilder<T>.() -> Unit,
+public inline fun <reified T : Any> DataTree(
+    noinline block: DataSetBuilder<T>.() -> Unit,
 ): DataTree<T> = DataTree(typeOf<T>(), block)
 
 @OptIn(DFExperimental::class)
-public suspend fun <T : Any> DataSet<T>.seal(): DataTree<T> = DataTree(dataType){
-    populate(this@seal)
+public fun <T : Any> DataSet<T>.seal(): DataTree<T> = DataTree(dataType) {
+    populateFrom(this@seal)
 }

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

@@ -4,8 +4,11 @@ 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
 
 
@@ -13,34 +16,58 @@ import kotlin.reflect.KType
  * A stateless filtered [DataSet]
  */
 public fun <T : Any> DataSet<T>.filter(
-    predicate: suspend (Name, Data<T>) -> Boolean,
-): ActiveDataSet<T> = object : ActiveDataSet<T> {
+    predicate: (Name, Meta) -> Boolean,
+): DataSource<T> = object : DataSource<T> {
+
     override val dataType: KType get() = this@filter.dataType
 
-    override fun flow(): Flow<NamedData<T>> =
-        this@filter.flow().filter { predicate(it.name, it.data) }
+    override val coroutineContext: CoroutineContext
+        get() = (this@filter as? DataSource)?.coroutineContext ?: EmptyCoroutineContext
 
-    override suspend fun getData(name: Name): Data<T>? = this@filter.getData(name)?.takeIf {
-        predicate(name, it)
+
+    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.getData(name) ?: return@flowFilter false
-        predicate(name, theData)
+        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 : ActiveDataSet<T> {
+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 fun flow(): Flow<NamedData<T>> = this@withNamePrefix.flow().map { it.data.named(prefix + it.name) }
+    override val coroutineContext: CoroutineContext
+        get() = (this@withNamePrefix as? DataSource)?.coroutineContext ?: EmptyCoroutineContext
 
-    override suspend fun getData(name: Name): Data<T>? =
-        name.removeHeadOrNull(name)?.let { this@withNamePrefix.getData(it) }
+    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 }
 }
@@ -50,22 +77,29 @@ else object : ActiveDataSet<T> {
  */
 public fun <T : Any> DataSet<T>.branch(branchName: Name): DataSet<T> = if (branchName.isEmpty()) {
     this
-} else object : ActiveDataSet<T> {
+} else object : DataSource<T> {
     override val dataType: KType get() = this@branch.dataType
 
-    override fun flow(): Flow<NamedData<T>> = this@branch.flow().mapNotNull {
-        it.name.removeHeadOrNull(branchName)?.let { name ->
-            it.data.named(name)
+    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 suspend fun getData(name: Name): Data<T>? = this@branch.getData(branchName + name)
+    override fun get(name: Name): Data<T>? = this@branch.get(branchName + name)
 
-    override val updates: Flow<Name> get() = this@branch.updates.mapNotNull { it.removeHeadOrNull(branchName) }
+    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.toName())
+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>? = getData(Name.EMPTY)
+public suspend fun <T : Any> DataSet<T>.rootData(): Data<T>? = get(Name.EMPTY)
 

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

@@ -1,20 +0,0 @@
-package space.kscience.dataforge.data
-
-import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
-
-
-/**
- * Get a metadata node for this set if it is present
- */
-public suspend fun DataSet<*>.getMeta(): Meta? = getData(DataSet.META_KEY)?.meta
-
-/**
- * Add meta-data node to a [DataSet]
- */
-public suspend fun DataSetBuilder<*>.meta(meta: Meta): Unit = emit(DataSet.META_KEY, Data.empty(meta))
-
-/**
- * Add meta-data node to a [DataSet]
- */
-public suspend fun DataSetBuilder<*>.meta(metaBuilder: MetaBuilder.() -> Unit): Unit = meta(Meta(metaBuilder))

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

@@ -1,18 +1,26 @@
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.flow.*
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaBuilder
+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 kotlin.contracts.InvocationKind
-import kotlin.contracts.contract
+import space.kscience.dataforge.names.Name
 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 suspend fun <T : Any> Data<T>.awaitWithMeta(): ValueWithMeta<T> = ValueWithMeta(meta, await())
+
+public data class NamedValueWithMeta<T>(val name: Name, val meta: Meta, val value: T)
+
+public suspend fun <T : Any> NamedData<T>.awaitWithMeta(): NamedValueWithMeta<T> =
+    NamedValueWithMeta(name, meta, await())
+
+
 /**
  * Lazily transform this data to another data. By convention [block] should not use external data (be pure).
  * @param coroutineContext additional [CoroutineContext] elements used for data computation.
@@ -28,7 +36,7 @@ public inline fun <T : Any, reified R : Any> Data<T>.map(
 }
 
 /**
- * Combine this data with the other data using [block]. See [map] for other details
+ * 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(
     other: Data<T2>,
@@ -48,13 +56,13 @@ public inline fun <T1 : Any, T2 : Any, reified R : Any> Data<T1>.combine(
 public inline fun <T : Any, reified R : Any> Collection<Data<T>>.reduceToData(
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    crossinline block: suspend (Collection<T>) -> R,
+    crossinline block: suspend (List<ValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     meta,
     coroutineContext,
     this
 ) {
-    block(map { it.await() })
+    block(map { it.awaitWithMeta() })
 }
 
 @DFInternal
@@ -62,17 +70,16 @@ public fun <K, T : Any, R : Any> Map<K, Data<T>>.reduceToData(
     outputType: KType,
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    block: suspend (Map<K, T>) -> R,
+    block: suspend (Map<K, ValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     outputType,
     meta,
     coroutineContext,
     this.values
 ) {
-    block(mapValues { it.value.await() })
+    block(mapValues { it.value.awaitWithMeta() })
 }
 
-
 /**
  * Lazily reduce a [Map] of [Data] with any static key.
  * @param K type of the map key
@@ -82,56 +89,91 @@ public fun <K, T : Any, R : Any> Map<K, Data<T>>.reduceToData(
 public inline fun <K, T : Any, reified R : Any> Map<K, Data<T>>.reduceToData(
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    noinline block: suspend (Map<K, T>) -> R,
+    crossinline block: suspend (Map<K, ValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     meta,
     coroutineContext,
     this.values
 ) {
-    block(mapValues { it.value.await() })
+    block(mapValues { it.value.awaitWithMeta() })
 }
 
-//flow operations
+//Iterable operations
 
-/**
- * Transform a [Flow] of [NamedData] to a single [Data].
- */
 @DFInternal
-public suspend fun <T : Any, R : Any> Flow<NamedData<T>>.reduceToData(
+public inline fun <T : Any, R : Any> Iterable<Data<T>>.reduceToData(
     outputType: KType,
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    transformation: suspend (Flow<NamedData<T>>) -> R,
+    crossinline transformation: suspend (Collection<ValueWithMeta<T>>) -> R,
 ): Data<R> = Data(
     outputType,
     meta,
     coroutineContext,
     toList()
 ) {
-    transformation(this)
+    transformation(map { it.awaitWithMeta() })
 }
 
 @OptIn(DFInternal::class)
-public suspend inline fun <T : Any, reified R : Any> Flow<NamedData<T>>.reduceToData(
+public inline fun <T : Any, reified R : Any> Iterable<Data<T>>.reduceToData(
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    noinline transformation: suspend (Flow<NamedData<T>>) -> R,
+    crossinline transformation: suspend (Collection<ValueWithMeta<T>>) -> R,
 ): Data<R> = reduceToData(typeOf<R>(), coroutineContext, meta) {
     transformation(it)
 }
 
-/**
- * Fold a flow of named data into a single [Data]
- */
-public suspend inline fun <T : Any, reified R : Any> Flow<NamedData<T>>.foldToData(
+public inline fun <T : Any, reified R : Any> Iterable<Data<T>>.foldToData(
     initial: R,
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    noinline block: suspend (result: R, data: NamedData<T>) -> R,
+    crossinline block: suspend (result: R, data: ValueWithMeta<T>) -> R,
 ): Data<R> = reduceToData(
     coroutineContext, meta
 ) {
-    it.fold(initial, block)
+    it.fold(initial) { acc, t -> block(acc, t) }
+}
+
+/**
+ * Transform an [Iterable] of [NamedData] to a single [Data].
+ */
+@DFInternal
+public inline fun <T : Any, R : Any> Iterable<NamedData<T>>.reduceNamedToData(
+    outputType: KType,
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
+    meta: Meta = Meta.EMPTY,
+    crossinline transformation: suspend (Collection<NamedValueWithMeta<T>>) -> R,
+): Data<R> = Data(
+    outputType,
+    meta,
+    coroutineContext,
+    toList()
+) {
+    transformation(map { it.awaitWithMeta() })
+}
+
+@OptIn(DFInternal::class)
+public inline fun <T : Any, reified R : Any> Iterable<NamedData<T>>.reduceNamedToData(
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
+    meta: Meta = Meta.EMPTY,
+    crossinline transformation: suspend (Collection<NamedValueWithMeta<T>>) -> R,
+): Data<R> = reduceNamedToData(typeOf<R>(), coroutineContext, meta) {
+    transformation(it)
+}
+
+/**
+ * Fold a [Iterable] of named data into a single [Data]
+ */
+public inline fun <T : Any, reified R : Any> Iterable<NamedData<T>>.foldNamedToData(
+    initial: R,
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
+    meta: Meta = Meta.EMPTY,
+    crossinline block: suspend (result: R, data: NamedValueWithMeta<T>) -> R,
+): Data<R> = reduceNamedToData(
+    coroutineContext, meta
+) {
+    it.fold(initial) { acc, t -> block(acc, t) }
 }
 
 //DataSet operations
@@ -140,42 +182,40 @@ public suspend inline fun <T : Any, reified R : Any> Flow<NamedData<T>>.foldToDa
 public suspend fun <T : Any, R : Any> DataSet<T>.map(
     outputType: KType,
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    metaTransform: MetaBuilder.() -> Unit = {},
-    block: suspend (T) -> R,
+    metaTransform: MutableMeta.() -> Unit = {},
+    block: suspend (NamedValueWithMeta<T>) -> R,
 ): DataTree<R> = DataTree<R>(outputType) {
-    populate(
-        flow().map {
-            val newMeta = it.meta.toMutableMeta().apply(metaTransform).seal()
-            Data(outputType, newMeta, coroutineContext, listOf(it)) {
-                block(it.await())
-            }.named(it.name)
+    forEach {
+        val newMeta = it.meta.toMutableMeta().apply(metaTransform).seal()
+        val d = Data(outputType, newMeta, coroutineContext, listOf(it)) {
+            block(it.awaitWithMeta())
         }
-    )
+        data(it.name, d)
+    }
 }
 
 @OptIn(DFInternal::class)
 public suspend inline fun <T : Any, reified R : Any> DataSet<T>.map(
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
-    noinline metaTransform: MetaBuilder.() -> Unit = {},
-    noinline block: suspend (T) -> R,
+    noinline metaTransform: MutableMeta.() -> Unit = {},
+    noinline block: suspend (NamedValueWithMeta<T>) -> R,
 ): DataTree<R> = map(typeOf<R>(), coroutineContext, metaTransform, block)
 
-public suspend fun <T : Any> DataSet<T>.forEach(block: suspend (NamedData<T>) -> Unit) {
-    contract { callsInPlace(block, InvocationKind.EXACTLY_ONCE) }
-    flow().collect {
-        block(it)
+public inline fun <T : Any> DataSet<T>.forEach(block: (NamedData<T>) -> Unit) {
+    for (d in this) {
+        block(d)
     }
 }
 
-public suspend inline fun <T : Any, reified R : Any> DataSet<T>.reduceToData(
+public inline fun <T : Any, reified R : Any> DataSet<T>.reduceToData(
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    noinline transformation: suspend (Flow<NamedData<T>>) -> R,
-): Data<R> = flow().reduceToData(coroutineContext, meta, transformation)
+    crossinline transformation: suspend (Iterable<NamedValueWithMeta<T>>) -> R,
+): Data<R> = asIterable().reduceNamedToData(coroutineContext, meta, transformation)
 
-public suspend inline fun <T : Any, reified R : Any> DataSet<T>.foldToData(
+public inline fun <T : Any, reified R : Any> DataSet<T>.foldToData(
     initial: R,
     coroutineContext: CoroutineContext = EmptyCoroutineContext,
     meta: Meta = Meta.EMPTY,
-    noinline block: suspend (result: R, data: NamedData<T>) -> R,
-): Data<R> = flow().foldToData(initial, coroutineContext, meta, block)
+    crossinline block: suspend (result: R, data: NamedValueWithMeta<T>) -> R,
+): Data<R> = asIterable().foldNamedToData(initial, coroutineContext, meta, block)

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

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

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

@@ -0,0 +1,85 @@
+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.names.Name
+import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
+import kotlin.reflect.KType
+import kotlin.reflect.full.isSubtypeOf
+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>? =
+    if (!this.type.isSubtypeOf(type)) {
+        null
+    } else {
+        object : Data<R> by (this as Data<R>) {
+            override val type: KType = type
+        }
+    }
+
+/**
+ * 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
+ */
+@OptIn(DFExperimental::class)
+public fun <R : Any> DataSet<*>.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
+    }
+}
+
+/**
+ * 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)
+
+/**
+ * Select a single datum if it is present and of given [type]
+ */
+public fun <R : Any> DataSet<*>.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>? =
+    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))

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

@@ -0,0 +1,40 @@
+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)
+
+/**
+ * Append node
+ */
+context(DataSetBuilder<T>) public infix fun <T : Any> String.put(dataSet: DataSet<T>): Unit =
+    node(Name.parse(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)
+
+/**
+ * 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/jvmMain/kotlin/space/kscience/dataforge/data/select.kt

@@ -1,64 +0,0 @@
-package space.kscience.dataforge.data
-
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.filter
-import kotlinx.coroutines.flow.map
-import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.matches
-import space.kscience.dataforge.names.toName
-import kotlin.reflect.KType
-import kotlin.reflect.full.isSubtypeOf
-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>? =
-    if (!this.type.isSubtypeOf(type)) null else object : Data<R> by (this as Data<R>) {
-        override val type: KType = type
-    }
-
-/**
- * Select all data matching given type and filters. Does not modify paths
- */
-@OptIn(DFExperimental::class)
-@PublishedApi
-internal fun <R : Any> DataSet<*>.select(
-    type: KType,
-    namePattern: Name? = null,
-): ActiveDataSet<R> = object : ActiveDataSet<R> {
-    override val dataType = type
-
-
-    override fun flow(): Flow<NamedData<R>> = this@select.flow().filter { datum ->
-        datum.type.isSubtypeOf(type) && (namePattern == null || datum.name.matches(namePattern))
-    }.map {
-        @Suppress("UNCHECKED_CAST")
-        it as NamedData<R>
-    }
-
-    override suspend fun getData(name: Name): Data<R>? = this@select.getData(name)?.castOrNull(type)
-
-    override val updates: Flow<Name> = this@select.updates.filter {
-        val datum = this@select.getData(it)
-        datum?.type?.isSubtypeOf(type) ?: false
-    }
-
-}
-
-/**
- * Select a single datum of the appropriate type
- */
-public inline fun <reified R : Any> DataSet<*>.select(namePattern: Name? = null): DataSet<R> =
-    select(typeOf<R>(), namePattern)
-
-public suspend fun <R : Any> DataSet<*>.selectOne(type: KType, name: Name): NamedData<R>? =
-    getData(name)?.castOrNull<R>(type)?.named(name)
-
-public suspend inline fun <reified R : Any> DataSet<*>.selectOne(name: Name): NamedData<R>? = selectOne(typeOf<R>(), name)
-
-public suspend inline fun <reified R : Any> DataSet<*>.selectOne(name: String): NamedData<R>? =
-    selectOne(typeOf<R>(), name.toName())

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

@@ -1,42 +1,50 @@
 package space.kscience.dataforge.data
 
-import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.delay
+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.misc.DFExperimental
 import kotlin.test.assertEquals
 
-@Suppress("EXPERIMENTAL_API_USAGE")
-class ActionsTest {
-    val data: DataTree<Int> = runBlocking {
-        DataTree {
+@OptIn(DFExperimental::class, ExperimentalCoroutinesApi::class)
+internal class ActionsTest {
+    @Test
+    fun testStaticMapAction() = runTest {
+        val data: DataTree<Int> = DataTree {
             repeat(10) {
                 static(it.toString(), it)
             }
         }
-    }
 
-    @Test
-    fun testStaticMapAction() {
         val plusOne = Action.map<Int, Int> {
             result { it + 1 }
         }
-        runBlocking {
-            val result = plusOne.execute(data)
-            assertEquals(2, result.getData("1")?.await())
-        }
+        val result = plusOne(data)
+        assertEquals(2, result["1"]?.await())
     }
 
     @Test
-    fun testDynamicMapAction() {
+    fun testDynamicMapAction() = runTest {
+        val data: DataSourceBuilder<Int> = DataSource()
+
         val plusOne = Action.map<Int, Int> {
             result { it + 1 }
         }
-        val datum = runBlocking {
-            val result = plusOne.execute(data, scope = this)
-            result.getData("1")?.await()
+
+        val result = plusOne(data)
+
+        repeat(10) {
+            data.static(it.toString(), it)
         }
-        assertEquals(2, datum)
+
+        delay(20)
+
+        assertEquals(2, result["1"]?.await())
+        data.close()
     }
 
 }

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

@@ -1,9 +1,8 @@
 package space.kscience.dataforge.data
 
 import kotlinx.coroutines.*
-import kotlinx.coroutines.flow.collect
 import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.toName
+import space.kscience.dataforge.names.asName
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -20,10 +19,10 @@ internal class DataTreeBuilderTest {
             static("c.f", "c.f")
         }
         runBlocking {
-            assertEquals("a", node.getData("primary.a")?.await())
-            assertEquals("b", node.getData("primary.b")?.await())
-            assertEquals("c.d", node.getData("c.d")?.await())
-            assertEquals("c.f", node.getData("c.f")?.await())
+            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())
         }
     }
 
@@ -43,12 +42,12 @@ internal class DataTreeBuilderTest {
                 static("b", "b")
             }
             static("root", "root")
-            populate(updateData)
+            populateFrom(updateData)
         }
 
         runBlocking {
-            assertEquals("a", node.getData("update.a")?.await())
-            assertEquals("a", node.getData("primary.a")?.await())
+            assertEquals("a", node["update.a"]?.await())
+            assertEquals("a", node["primary.a"]?.await())
         }
     }
 
@@ -57,7 +56,7 @@ internal class DataTreeBuilderTest {
         try {
             lateinit var updateJob: Job
             supervisorScope {
-                val subNode = ActiveDataTree<Int> {
+                val subNode = DataSource<Int> {
                     updateJob = launch {
                         repeat(10) {
                             delay(10)
@@ -71,8 +70,8 @@ internal class DataTreeBuilderTest {
                         println(it)
                     }
                 }
-                val rootNode = ActiveDataTree<Int> {
-                    setAndObserve("sub".toName(), subNode)
+                val rootNode = DataSource<Int> {
+                    setAndWatch("sub".asName(), subNode)
                 }
 
                 launch {
@@ -81,11 +80,11 @@ internal class DataTreeBuilderTest {
                     }
                 }
                 updateJob.join()
-                assertEquals(9, rootNode.getData("sub.value")?.await())
+                assertEquals(9, rootNode["sub.value"]?.await())
                 cancel()
             }
         } catch (t: Throwable) {
-            if (t !is CancellationException) throw  t
+            if (t !is CancellationException) throw t
         }
 
     }

dataforge-io/README.md

@@ -0,0 +1,23 @@
+# Module dataforge-io
+
+IO module
+
+## Usage
+
+## Artifact:
+
+The Maven coordinates of this project are `space.kscience:dataforge-io:0.7.0`.
+
+**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")
+}
+```

dataforge-io/build.gradle.kts

@@ -1,29 +1,26 @@
 plugins {
-    id("ru.mipt.npm.gradle.mpp")
-    id("ru.mipt.npm.gradle.native")
+    id("space.kscience.gradle.mpp")
 }
 
 description = "IO module"
 
+val ioVersion = "0.2.1"
+
 kscience {
-    useSerialization(sourceSet = ru.mipt.npm.gradle.DependencySourceSet.TEST) {
+    jvm()
+    js()
+    native()
+    useSerialization()
+    useSerialization(sourceSet = space.kscience.gradle.DependencySourceSet.TEST) {
         cbor()
     }
-}
-
-//val ioVersion by rootProject.extra("0.2.0-npm-dev-11")
-
-kotlin {
-    sourceSets {
-        commonMain {
-            dependencies {
-                api(project(":dataforge-context"))
-                api("io.ktor:ktor-io:${ru.mipt.npm.gradle.KScienceVersions.ktorVersion}")
-            }
-        }
+    dependencies {
+        api(projects.dataforgeContext)
+        api("org.jetbrains.kotlinx:kotlinx-io-core:$ioVersion")
+        api("org.jetbrains.kotlinx:kotlinx-io-bytestring:$ioVersion")
     }
 }
 
 readme{
-    maturity = ru.mipt.npm.gradle.Maturity.PROTOTYPE
+    maturity = space.kscience.gradle.Maturity.EXPERIMENTAL
 }

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

@@ -0,0 +1,23 @@
+# Module dataforge-io-yaml
+
+YAML meta IO
+
+## Usage
+
+## Artifact:
+
+The Maven coordinates of this project are `space.kscience:dataforge-io-yaml:0.7.0`.
+
+**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")
+}
+```

dataforge-io/dataforge-io-yaml/build.gradle.kts

@@ -1,32 +1,23 @@
 plugins {
-    id("ru.mipt.npm.gradle.mpp")
-//    id("ru.mipt.npm.gradle.native")
+    id("space.kscience.gradle.mpp")
 }
 
 description = "YAML meta IO"
 
 kscience {
-    useSerialization{
-        yamlKt("0.9.0-dev-1")
+    jvm()
+    js()
+    native()
+    dependencies {
+        api(projects.dataforgeIo)
     }
-}
-
-repositories{
-    maven("https://dl.bintray.com/mamoe/yamlkt")
-}
-
-kotlin {
-    sourceSets {
-        commonMain{
-            dependencies {
-                api(project(":dataforge-io"))
-            }
-        }
+    useSerialization{
+        yamlKt()
     }
 }
 
 readme{
-    maturity = ru.mipt.npm.gradle.Maturity.PROTOTYPE
+    maturity = space.kscience.gradle.Maturity.PROTOTYPE
     description ="""
         YAML meta converters and Front Matter envelope format
     """.trimIndent()

dataforge-io/dataforge-io-yaml/src/commonMain/kotlin/space/kscience/dataforge/io/yaml/FrontMatterEnvelopeFormat.kt

@@ -1,123 +1,97 @@
 package space.kscience.dataforge.io.yaml
 
-import io.ktor.utils.io.core.Input
-import io.ktor.utils.io.core.Output
-import io.ktor.utils.io.core.readBytes
-import io.ktor.utils.io.core.readUTF8Line
+import kotlinx.io.Sink
+import kotlinx.io.Source
+import kotlinx.io.bytestring.ByteString
+import kotlinx.io.bytestring.encodeToByteString
+import kotlinx.io.readByteString
+import kotlinx.io.writeString
 import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.io.*
-import space.kscience.dataforge.io.IOFormat.Companion.META_KEY
-import space.kscience.dataforge.io.IOFormat.Companion.NAME_KEY
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.misc.DFExperimental
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.plus
 
-@DFExperimental
 public class FrontMatterEnvelopeFormat(
     private val io: IOPlugin,
     private val meta: Meta = Meta.EMPTY,
+    private val metaFormatFactory: MetaFormatFactory = YamlMetaFormat,
 ) : EnvelopeFormat {
 
-    override fun readPartial(input: Input): PartialEnvelope {
-        var line: String
-        var offset = 0u
-        do {
-            line = input.readUTF8Line() ?: error("Input does not contain front matter separator")
-            offset += line.encodeToByteArray().size.toUInt()
-        } while (!line.startsWith(space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.SEPARATOR))
+    override fun readFrom(binary: Binary): Envelope = binary.read {
+        var offset = 0
 
-        val readMetaFormat =
-            space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.metaTypeRegex.matchEntire(line)?.groupValues?.first()
-                ?.let { io.resolveMetaFormat(it) } ?: space.kscience.dataforge.io.yaml.YamlMetaFormat
+        offset += discardWithSeparator(
+            SEPARATOR,
+            atMost = 1024,
+        )
 
-        //TODO replace by preview
-        val meta = Binary {
-            do {
-                line = input.readSafeUtf8Line()
-                writeUtf8String(line + "\r\n")
-                offset += line.encodeToByteArray().size.toUInt()
-            } while (!line.startsWith(space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.SEPARATOR))
-        }.read {
-            readMetaFormat.readMeta(input)
+        val line = ByteArray {
+            offset += readWithSeparatorTo(this, "\n".encodeToByteString())
+        }.decodeToString()
 
+        val readMetaFormat = line.trim().takeIf { it.isNotBlank() }?.let { io.resolveMetaFormat(it) } ?: YamlMetaFormat
+
+        val packet = ByteArray {
+            offset += readWithSeparatorTo(this, SEPARATOR)
         }
-        return PartialEnvelope(meta, offset, null)
+
+        offset += discardLine()
+
+        val meta = readMetaFormat.readFrom(packet.asBinary())
+        Envelope(meta, binary.view(offset))
     }
 
-    override fun readObject(input: Input): Envelope {
-        var line: String
-        do {
-            line = input.readSafeUtf8Line() //?: error("Input does not contain front matter separator")
-        } while (!line.startsWith(space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.SEPARATOR))
+    override fun readFrom(source: Source): Envelope = readFrom(source.readBinary())
 
-        val readMetaFormat =
-            space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.metaTypeRegex.matchEntire(line)?.groupValues?.first()
-                ?.let { io.resolveMetaFormat(it) } ?: space.kscience.dataforge.io.yaml.YamlMetaFormat
-
-        val meta = Binary {
-            do {
-                writeUtf8String(input.readSafeUtf8Line() + "\r\n")
-            } while (!line.startsWith(space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.SEPARATOR))
-        }.read {
-            readMetaFormat.readMeta(input)
-        }
-        val bytes = input.readBytes()
-        val data = bytes.asBinary()
-        return SimpleEnvelope(meta, data)
-    }
-
-    override fun writeEnvelope(
-        output: Output,
-        envelope: Envelope,
-        metaFormatFactory: MetaFormatFactory,
-        formatMeta: Meta,
+    override fun writeTo(
+        sink: Sink,
+        obj: Envelope,
     ) {
-        val metaFormat = metaFormatFactory(formatMeta, this@FrontMatterEnvelopeFormat.io.context)
-        output.writeRawString("${space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.SEPARATOR}\r\n")
-        metaFormat.run { this.writeObject(output, envelope.meta) }
-        output.writeRawString("${space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.SEPARATOR}\r\n")
+        val metaFormat = metaFormatFactory.build(io.context, meta)
+        val formatSuffix = if (metaFormat is YamlMetaFormat) "" else metaFormatFactory.shortName
+        sink.writeString("$SEPARATOR${formatSuffix}\r\n")
+        metaFormat.run { metaFormat.writeTo(sink, obj.meta) }
+        sink.writeString("$SEPARATOR\r\n")
         //Printing data
-        envelope.data?.let { data ->
-            output.writeBinary(data)
+        obj.data?.let { data ->
+            sink.writeBinary(data)
         }
     }
 
-    override fun toMeta(): Meta = Meta {
-        NAME_KEY put name.toString()
-        META_KEY put meta
-    }
-
     public companion object : EnvelopeFormatFactory {
-        public const val SEPARATOR: String = "---"
+        public val SEPARATOR: ByteString = "---".encodeToByteString()
 
         private val metaTypeRegex = "---(\\w*)\\s*".toRegex()
 
-        override fun invoke(meta: Meta, context: Context): EnvelopeFormat {
-            return space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat(context.io, meta)
+        override val name: Name = EnvelopeFormatFactory.ENVELOPE_FACTORY_NAME + "frontMatter"
+
+        override fun build(context: Context, meta: Meta): EnvelopeFormat {
+            return FrontMatterEnvelopeFormat(context.io, meta)
         }
 
         override fun peekFormat(io: IOPlugin, binary: Binary): EnvelopeFormat? = binary.read {
-            val line = readSafeUtf8Line()
-            return@read if (line.startsWith("---")) {
-                space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.invoke()
+            //read raw string to avoid UTF issues
+            val line = readByteString(3)
+            return@read if (line == "---".encodeToByteString()) {
+                default
             } else {
                 null
             }
         }
 
-        private val default by lazy { space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.invoke() }
+        private val default by lazy { build(Global, Meta.EMPTY) }
 
-        override fun readPartial(input: Input): PartialEnvelope =
-            space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.default.readPartial(input)
+        override fun readFrom(binary: Binary): Envelope = default.readFrom(binary)
 
-        override fun writeEnvelope(
-            output: Output,
-            envelope: Envelope,
-            metaFormatFactory: MetaFormatFactory,
-            formatMeta: Meta,
-        ): Unit = space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.default.writeEnvelope(output, envelope, metaFormatFactory, formatMeta)
+        override fun writeTo(
+            sink: Sink,
+            obj: Envelope,
+        ): Unit = default.writeTo(sink, obj)
 
 
-        override fun readObject(input: Input): Envelope = space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.Companion.default.readObject(input)
+        override fun readFrom(source: Source): Envelope = default.readFrom(source)
 
     }
 }

dataforge-io/dataforge-io-yaml/src/commonMain/kotlin/space/kscience/dataforge/io/yaml/YamlMetaFormat.kt

@@ -1,82 +1,84 @@
 package space.kscience.dataforge.io.yaml
 
-import io.ktor.utils.io.core.Input
-import io.ktor.utils.io.core.Output
+import kotlinx.io.Sink
+import kotlinx.io.Source
+import kotlinx.io.readString
+import kotlinx.io.writeString
 import net.mamoe.yamlkt.*
 import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.io.IOFormat.Companion.META_KEY
-import space.kscience.dataforge.io.IOFormat.Companion.NAME_KEY
 import space.kscience.dataforge.io.MetaFormat
 import space.kscience.dataforge.io.MetaFormatFactory
-import space.kscience.dataforge.io.readUtf8String
-import space.kscience.dataforge.io.writeUtf8String
 import space.kscience.dataforge.meta.*
-import space.kscience.dataforge.meta.descriptors.ItemDescriptor
-import space.kscience.dataforge.meta.descriptors.NodeDescriptor
-import space.kscience.dataforge.misc.DFExperimental
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.meta.descriptors.get
 import space.kscience.dataforge.names.NameToken
 import space.kscience.dataforge.names.withIndex
-import space.kscience.dataforge.values.ListValue
-import space.kscience.dataforge.values.Null
-import space.kscience.dataforge.values.parseValue
+import kotlin.collections.component1
+import kotlin.collections.component2
+import kotlin.collections.set
 
 public fun Meta.toYaml(): YamlMap {
     val map: Map<String, Any?> = items.entries.associate { (key, item) ->
-        key.toString() to when (item) {
-            is MetaItemValue -> {
-                item.value.value
-            }
-            is MetaItemNode -> {
-                item.node.toYaml()
-            }
+        key.toString() to if (item.isLeaf) {
+            item.value?.value
+        } else {
+            item.toYaml()
         }
     }
+
     return YamlMap(map)
 }
 
-private class YamlMeta(private val yamlMap: YamlMap, private val descriptor: NodeDescriptor? = null) : MetaBase() {
+private class YamlMeta(private val yamlMap: YamlMap, private val descriptor: MetaDescriptor? = null) : Meta {
 
-    private fun buildItems(): Map<NameToken, MetaItem> {
-        val map = LinkedHashMap<NameToken, MetaItem>()
+    override val value: Value?
+        get() = yamlMap.getStringOrNull(null)?.let { Value.parse(it) }
+
+    private fun buildItems(): Map<NameToken, Meta> {
+        val map = LinkedHashMap<NameToken, Meta>()
 
         yamlMap.content.entries.forEach { (key, value) ->
             val stringKey = key.toString()
-            val itemDescriptor = descriptor?.items?.get(stringKey)
+            val itemDescriptor = descriptor?.get(stringKey)
             val token = NameToken(stringKey)
             when (value) {
-                YamlNull -> Null.asMetaItem()
-                is YamlLiteral -> map[token] = value.content.parseValue().asMetaItem()
-                is YamlMap -> map[token] = value.toMeta().asMetaItem()
+                YamlNull -> Meta(Null)
+                is YamlLiteral -> map[token] = Meta(Value.parse(value.content))
+                is YamlMap -> map[token] = value.toMeta()
                 is YamlList -> if (value.all { it is YamlLiteral }) {
                     val listValue = ListValue(
                         value.map {
                             //We already checked that all values are primitives
-                            (it as YamlLiteral).content.parseValue()
+                            Value.parse((it as YamlLiteral).content)
                         }
                     )
-                    map[token] = MetaItemValue(listValue)
+                    map[token] = Meta(listValue)
                 } else value.forEachIndexed { index, yamlElement ->
-                    val indexKey = (itemDescriptor as? NodeDescriptor)?.indexKey ?: ItemDescriptor.DEFAULT_INDEX_KEY
+                    val indexKey = itemDescriptor?.indexKey
                     val indexValue: String = (yamlElement as? YamlMap)?.getStringOrNull(indexKey)
                         ?: index.toString() //In case index is non-string, the backward transformation will be broken.
 
                     val tokenWithIndex = token.withIndex(indexValue)
-                    map[tokenWithIndex] = yamlElement.toMetaItem(itemDescriptor)
+                    map[tokenWithIndex] = yamlElement.toMeta(itemDescriptor)
                 }
             }
         }
         return map
     }
 
-    override val items: Map<NameToken, MetaItem> get() = buildItems()
+    override val items: Map<NameToken, Meta> get() = buildItems()
+
+    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)
 }
 
-public fun YamlElement.toMetaItem(descriptor: ItemDescriptor? = null): MetaItem = when (this) {
-    YamlNull -> Null.asMetaItem()
-    is YamlLiteral -> content.parseValue().asMetaItem()
-    is YamlMap -> toMeta().asMetaItem()
+public fun YamlElement.toMeta(descriptor: MetaDescriptor? = null): Meta = when (this) {
+    YamlNull -> Meta(Null)
+    is YamlLiteral -> Meta(Value.parse(content))
+    is YamlMap -> toMeta()
     //We can't return multiple items therefore we create top level node
-    is YamlList -> YamlMap(mapOf("@yamlArray" to this)).toMetaItem(descriptor)
+    is YamlList -> YamlMap(mapOf("@yamlArray" to this)).toMeta(descriptor)
 }
 
 public fun YamlMap.toMeta(): Meta = YamlMeta(this)
@@ -85,38 +87,32 @@ public fun YamlMap.toMeta(): Meta = YamlMeta(this)
 /**
  * Represent meta as Yaml
  */
-@DFExperimental
 public class YamlMetaFormat(private val meta: Meta) : MetaFormat {
 
-    override fun writeMeta(output: Output, meta: Meta, descriptor: NodeDescriptor?) {
-        val yaml = meta.toYaml()
-        val string = Yaml.encodeToString(yaml)
-        output.writeUtf8String(string)
+    override fun writeMeta(sink: Sink, meta: Meta, descriptor: MetaDescriptor?) {
+        val yaml: YamlMap = meta.toYaml()
+        val string = Yaml.encodeToString(YamlMap.serializer(), yaml)
+        sink.writeString(string)
     }
 
-    override fun readMeta(input: Input, descriptor: NodeDescriptor?): Meta {
-        val yaml = Yaml.decodeYamlMapFromString(input.readUtf8String())
+    override fun readMeta(source: Source, descriptor: MetaDescriptor?): Meta {
+        val yaml = Yaml.decodeYamlMapFromString(source.readString())
         return yaml.toMeta()
     }
 
-    override fun toMeta(): Meta = Meta {
-        NAME_KEY put space.kscience.dataforge.io.yaml.FrontMatterEnvelopeFormat.name.toString()
-        META_KEY put meta
-    }
-
     public companion object : MetaFormatFactory {
-        override fun invoke(meta: Meta, context: Context): MetaFormat = YamlMetaFormat(meta)
+        override fun build(context: Context, meta: Meta): MetaFormat = YamlMetaFormat(meta)
 
         override val shortName: String = "yaml"
 
         override val key: Short = 0x594d //YM
 
-        private val default = YamlMetaFormat()
+        private val default = YamlMetaFormat(Meta.EMPTY)
 
-        override fun writeMeta(output: Output, meta: Meta, descriptor: NodeDescriptor?): Unit =
-            default.writeMeta(output, meta, descriptor)
+        override fun writeMeta(sink: Sink, meta: Meta, descriptor: MetaDescriptor?): Unit =
+            default.writeMeta(sink, meta, descriptor)
 
-        override fun readMeta(input: Input, descriptor: NodeDescriptor?): Meta =
-            default.readMeta(input, descriptor)
+        override fun readMeta(source: Source, descriptor: MetaDescriptor?): Meta =
+            default.readMeta(source, descriptor)
     }
 }

dataforge-io/dataforge-io-yaml/src/commonMain/kotlin/space/kscience/dataforge/io/yaml/YamlPlugin.kt

@@ -0,0 +1,30 @@
+package space.kscience.dataforge.io.yaml
+
+import space.kscience.dataforge.context.AbstractPlugin
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.context.PluginFactory
+import space.kscience.dataforge.context.PluginTag
+import space.kscience.dataforge.io.EnvelopeFormatFactory
+import space.kscience.dataforge.io.IOPlugin
+import space.kscience.dataforge.io.MetaFormatFactory
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.asName
+
+public class YamlPlugin(meta: Meta) : AbstractPlugin(meta) {
+    public val io: IOPlugin by require(IOPlugin)
+
+    override val tag: PluginTag get() = Companion.tag
+
+    override fun content(target: String): Map<Name, Any> = when (target) {
+        MetaFormatFactory.META_FORMAT_TYPE -> mapOf("yaml".asName() to YamlMetaFormat)
+        EnvelopeFormatFactory.ENVELOPE_FORMAT_TYPE -> mapOf(FrontMatterEnvelopeFormat.name to FrontMatterEnvelopeFormat)
+        else -> super.content(target)
+    }
+
+    public companion object : PluginFactory<YamlPlugin> {
+        override val tag: PluginTag = PluginTag("io.yaml", group = PluginTag.DATAFORGE_GROUP)
+
+        override fun build(context: Context, meta: Meta): YamlPlugin = YamlPlugin(meta)
+    }
+}

dataforge-io/dataforge-io-yaml/src/commonTest/kotlin/space/kscience/dataforge/io/yaml/FrontMatterEnvelopeFormatTest.kt

@@ -0,0 +1,37 @@
+@file:OptIn(DFExperimental::class)
+
+package space.kscience.dataforge.io.yaml
+
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.io.io
+import space.kscience.dataforge.io.readEnvelope
+import space.kscience.dataforge.io.toByteArray
+import space.kscience.dataforge.meta.get
+import space.kscience.dataforge.meta.string
+import space.kscience.dataforge.misc.DFExperimental
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+internal class FrontMatterEnvelopeFormatTest {
+
+    val context = Context {
+        plugin(YamlPlugin)
+    }
+
+    @Test
+    fun frontMatter(){
+        val text = """
+            ---
+            content_type: magprog
+            magprog_section: contacts
+            section_title: Контакты
+            language: ru
+            ---
+            Some text here
+        """.trimIndent()
+
+        val envelope = context.io.readEnvelope(text)
+        assertEquals("Some text here", envelope.data!!.toByteArray().decodeToString().trim())
+        assertEquals("magprog", envelope.meta["content_type"].string)
+    }
+}

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

@@ -1,6 +1,9 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.*
+import kotlinx.io.Sink
+import kotlinx.io.Source
+import kotlinx.io.buffered
+import kotlinx.io.readByteArray
 import kotlin.math.min
 
 /**
@@ -12,11 +15,20 @@ public interface Binary {
 
     public val size: Int
 
+
     /**
      * Read maximum of [atMost] bytes as input from the binary, starting at [offset]. The generated input is always closed
      * when leaving scope, so it could not be leaked outside of scope of [block].
      */
-    public fun <R> read(offset: Int = 0, atMost: Int = size - offset, block: Input.() -> R): R
+    public fun <R> read(offset: Int = 0, atMost: Int = size - offset, block: Source.() -> R): R
+
+    public suspend fun <R> readSuspend(offset: Int = 0, atMost: Int = size - offset, block: suspend Source.() -> R): R
+
+    /**
+     * Read a binary with given [offset] relative to this binary and given [binarySize].
+     * In general, the resulting binary is of the same type as this one, but it is not guaranteed.
+     */
+    public fun view(offset: Int, binarySize: Int = size - offset): Binary
 
     public companion object {
         public val EMPTY: Binary = ByteArrayBinary(ByteArray(0))
@@ -29,46 +41,67 @@ internal class ByteArrayBinary(
     override val size: Int = array.size - start,
 ) : Binary {
 
-    override fun <R> read(offset: Int, atMost: Int, block: Input.() -> R): R {
+    override fun <R> read(offset: Int, atMost: Int, block: Source.() -> R): R {
         require(offset >= 0) { "Offset must be positive" }
         require(offset < array.size) { "Offset $offset is larger than array size" }
-        val input = ByteReadPacket(
+
+        return ByteArraySource(
             array,
             offset + start,
             min(atMost, size - offset)
-        )
-        return input.use(block)
+        ).buffered().use(block)
     }
+
+    override suspend fun <R> readSuspend(offset: Int, atMost: Int, block: suspend Source.() -> R): R {
+        require(offset >= 0) { "Offset must be positive" }
+        require(offset < array.size) { "Offset $offset is larger than array size" }
+
+        val input = ByteArraySource(
+            array,
+            offset + start,
+            min(atMost, size - offset)
+        ).buffered()
+
+        return try {
+            block(input)
+        } finally {
+            input.close()
+        }
+    }
+
+    override fun view(offset: Int, binarySize: Int): ByteArrayBinary =
+        ByteArrayBinary(array, start + offset, binarySize)
 }
 
 public fun ByteArray.asBinary(): Binary = ByteArrayBinary(this)
 
 /**
- * Produce a [buildByteArray] representing an exact copy of this [Binary]
+ * Produce a [ByteArray] representing an exact copy of this [Binary]
  */
 public fun Binary.toByteArray(): ByteArray = if (this is ByteArrayBinary) {
-    array.copyOf() // TODO do we need to ensure data safety here?
+    array.copyOfRange(start, start + size) // TODO do we need to ensure data safety here?
 } else {
     read {
-        readBytes()
+        readByteArray()
     }
 }
 
-public fun Input.readBinary(size: Int): Binary {
-    val array = readBytes(size)
+//TODO optimize for file-based Inputs
+public fun Source.readBinary(size: Int? = null): Binary {
+    val array = if (size == null) readByteArray() else readByteArray(size)
     return ByteArrayBinary(array)
 }
 
 /**
  * Direct write of binary to the output. Returns the number of bytes written
  */
-public fun Output.writeBinary(binary: Binary): Int {
+public fun Sink.writeBinary(binary: Binary): Int {
     return if (binary is ByteArrayBinary) {
-        writeFully(binary.array, binary.start, binary.start + binary.size)
+        write(binary.array, binary.start, binary.start + binary.size)
         binary.size
     } else {
         binary.read {
-            copyTo(this@writeBinary).toInt()
+            transferTo(this@writeBinary).toInt()
         }
     }
 }

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

@@ -1,133 +0,0 @@
-package space.kscience.dataforge.io
-
-import io.ktor.utils.io.core.*
-import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.meta.*
-import space.kscience.dataforge.meta.descriptors.NodeDescriptor
-import space.kscience.dataforge.values.*
-
-/**
- * A DataForge-specific simplified binary format for meta
- * TODO add description
- */
-public object BinaryMetaFormat : MetaFormat, MetaFormatFactory {
-    override val shortName: String = "bin"
-    override val key: Short = 0x4249//BI
-
-    override fun invoke(meta: Meta, context: Context): MetaFormat = this
-
-    override fun readMeta(input: Input, descriptor: NodeDescriptor?): Meta {
-        return (input.readMetaItem() as MetaItemNode).node
-    }
-
-    private fun Output.writeChar(char: Char) = writeByte(char.toByte())
-
-    private fun Output.writeString(str: String) {
-        writeInt(str.length)
-        writeFully(str.encodeToByteArray())
-    }
-
-    public fun Output.writeValue(value: Value): Unit = when (value.type) {
-        ValueType.NUMBER -> when (value.value) {
-            is Short -> {
-                writeChar('s')
-                writeShort(value.short)
-            }
-            is Int -> {
-                writeChar('i')
-                writeInt(value.int)
-            }
-            is Long -> {
-                writeChar('l')
-                writeLong(value.long)
-            }
-            is Float -> {
-                writeChar('f')
-                writeFloat(value.float)
-            }
-            else -> {
-                writeChar('d')
-                writeDouble(value.double)
-            }
-        }
-        ValueType.STRING -> {
-            writeChar('S')
-            writeString(value.string)
-        }
-        ValueType.BOOLEAN -> {
-            if (value.boolean) {
-                writeChar('+')
-            } else {
-                writeChar('-')
-            }
-        }
-        ValueType.NULL -> {
-            writeChar('N')
-        }
-        ValueType.LIST -> {
-            writeChar('L')
-            writeInt(value.list.size)
-            value.list.forEach {
-                writeValue(it)
-            }
-        }
-    }
-
-    override fun writeMeta(
-        output: Output,
-        meta: Meta,
-        descriptor: space.kscience.dataforge.meta.descriptors.NodeDescriptor?,
-    ) {
-        output.writeChar('M')
-        output.writeInt(meta.items.size)
-        meta.items.forEach { (key, item) ->
-            output.writeString(key.toString())
-            when (item) {
-                is MetaItemValue -> {
-                    output.writeValue(item.value)
-                }
-                is MetaItemNode -> {
-                    writeObject(output, item.node)
-                }
-            }
-        }
-    }
-
-    private fun Input.readString(): String {
-        val length = readInt()
-        val array = readBytes(length)
-        return array.decodeToString()
-    }
-
-    @Suppress("UNCHECKED_CAST")
-    public fun Input.readMetaItem(): TypedMetaItem<MetaBuilder> {
-        return when (val keyChar = readByte().toChar()) {
-            'S' -> MetaItemValue(StringValue(readString()))
-            'N' -> MetaItemValue(Null)
-            '+' -> MetaItemValue(True)
-            '-' -> MetaItemValue(True)
-            's' -> MetaItemValue(NumberValue(readShort()))
-            'i' -> MetaItemValue(NumberValue(readInt()))
-            'l' -> MetaItemValue(NumberValue(readInt()))
-            'f' -> MetaItemValue(NumberValue(readFloat()))
-            'd' -> MetaItemValue(NumberValue(readDouble()))
-            'L' -> {
-                val length = readInt()
-                val list = (1..length).map { (readMetaItem() as MetaItemValue).value }
-                MetaItemValue(Value.of(list))
-            }
-            'M' -> {
-                val length = readInt()
-                val meta = Meta {
-                    (1..length).forEach { _ ->
-                        val name = readString()
-                        val item = readMetaItem()
-                        set(name, item)
-                    }
-                }
-                MetaItemNode(meta)
-            }
-            else -> error("Unknown serialization key character: $keyChar")
-        }
-    }
-}

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

@@ -34,7 +34,9 @@ public interface Envelope {
     }
 }
 
-public class SimpleEnvelope(override val meta: Meta, override val data: Binary?) : Envelope
+internal class SimpleEnvelope(override val meta: Meta, override val data: Binary?) : Envelope
+
+public fun Envelope(meta: Meta, data: Binary?): Envelope = SimpleEnvelope(meta, data)
 
 /**
  * The purpose of the envelope

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

@@ -1,10 +1,10 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.Output
+import kotlinx.io.Sink
 import space.kscience.dataforge.meta.*
 
 public class EnvelopeBuilder : Envelope {
-    private val metaBuilder = MetaBuilder()
+    private val metaBuilder = MutableMeta()
 
     override var data: Binary? = null
     override var meta: Meta
@@ -13,7 +13,7 @@ public class EnvelopeBuilder : Envelope {
             metaBuilder.update(value)
         }
 
-    public fun meta(block: MetaBuilder.() -> Unit) {
+    public fun meta(block: MutableMeta.() -> Unit) {
         metaBuilder.apply(block)
     }
 
@@ -33,8 +33,8 @@ public class EnvelopeBuilder : Envelope {
     /**
      * Construct a data binary from given builder
      */
-    public fun data(block: Output.() -> Unit) {
-        data = buildByteArray { block() }.asBinary()
+    public inline fun data(block: Sink.() -> Unit) {
+        data = ByteArray { block() }.asBinary()
     }
 
     public fun seal(): Envelope = SimpleEnvelope(metaBuilder.seal(), data)

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

@@ -1,48 +1,27 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.Input
-import io.ktor.utils.io.core.Output
+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.Type
+import space.kscience.dataforge.misc.DfId
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
-/**
- * A partially read envelope with meta, but without data
- */
-public data class PartialEnvelope(val meta: Meta, val dataOffset: UInt, val dataSize: ULong?)
-
 public interface EnvelopeFormat : IOFormat<Envelope> {
+
     override val type: KType get() = typeOf<Envelope>()
-
-    public val defaultMetaFormat: MetaFormatFactory get() = JsonMetaFormat
-
-    public fun readPartial(input: Input): PartialEnvelope
-
-    public fun writeEnvelope(
-        output: Output,
-        envelope: Envelope,
-        metaFormatFactory: MetaFormatFactory = defaultMetaFormat,
-        formatMeta: Meta = Meta.EMPTY,
-    )
-
-    override fun readObject(input: Input): Envelope
-
-    override fun writeObject(output: Output, obj: Envelope): Unit = writeEnvelope(output, obj)
 }
 
-public fun EnvelopeFormat.read(input: Input): Envelope = readObject(input)
+public fun EnvelopeFormat.read(input: Source): Envelope = readFrom(input)
 
-@Type(ENVELOPE_FORMAT_TYPE)
+@DfId(ENVELOPE_FORMAT_TYPE)
 public interface EnvelopeFormatFactory : IOFormatFactory<Envelope>, EnvelopeFormat {
-    override val name: Name get() = "envelope".asName()
     override val type: KType get() = typeOf<Envelope>()
 
-    override fun invoke(meta: Meta, context: Context): EnvelopeFormat
+    override fun build(context: Context, meta: Meta): EnvelopeFormat
 
     /**
      * Try to infer specific format from input and return null if the attempt is failed.
@@ -51,6 +30,7 @@ public interface EnvelopeFormatFactory : IOFormatFactory<Envelope>, EnvelopeForm
     public fun peekFormat(io: IOPlugin, binary: Binary): EnvelopeFormat?
 
     public companion object {
+        public val ENVELOPE_FACTORY_NAME: Name = "envelope".asName()
         public const val ENVELOPE_FORMAT_TYPE: String = "io.format.envelope"
     }
 }

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

@@ -1,30 +1,29 @@
 package space.kscience.dataforge.io
 
+import kotlinx.io.bytestring.ByteString
+import kotlinx.io.bytestring.decodeToString
+import kotlinx.io.write
 import space.kscience.dataforge.io.Envelope.Companion.ENVELOPE_NODE_KEY
 import space.kscience.dataforge.io.PartDescriptor.Companion.DEFAULT_MULTIPART_DATA_SEPARATOR
 import space.kscience.dataforge.io.PartDescriptor.Companion.MULTIPART_DATA_TYPE
 import space.kscience.dataforge.io.PartDescriptor.Companion.MULTIPART_KEY
 import space.kscience.dataforge.io.PartDescriptor.Companion.PARTS_KEY
-import space.kscience.dataforge.io.PartDescriptor.Companion.PART_FORMAT_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.plus
-import space.kscience.dataforge.names.toName
 
 private class PartDescriptor : Scheme() {
     var offset by int(0)
     var size by int(0)
-    var partMeta by node("meta".toName())
+    var partMeta by node("meta".asName())
 
     companion object : SchemeSpec<PartDescriptor>(::PartDescriptor) {
         val MULTIPART_KEY = ENVELOPE_NODE_KEY + "multipart"
         val PARTS_KEY = MULTIPART_KEY + "parts"
         val SEPARATOR_KEY = MULTIPART_KEY + "separator"
 
-        const val DEFAULT_MULTIPART_DATA_SEPARATOR = "\r\n#~PART~#\r\n"
-
-        val PART_FORMAT_KEY = "format".asName()
+        val DEFAULT_MULTIPART_DATA_SEPARATOR = "\r\n#~PART~#\r\n".toAsciiByteString()
 
         const val MULTIPART_DATA_TYPE = "envelope.multipart"
     }
@@ -36,12 +35,12 @@ public typealias EnvelopeParts = List<EnvelopePart>
 
 public fun EnvelopeBuilder.multipart(
     parts: EnvelopeParts,
-    separator: String = DEFAULT_MULTIPART_DATA_SEPARATOR
+    separator: ByteString = DEFAULT_MULTIPART_DATA_SEPARATOR,
 ) {
     dataType = MULTIPART_DATA_TYPE
 
     var offsetCounter = 0
-    val separatorSize = separator.length
+    val separatorSize = separator.size
     val partDescriptors = parts.map { (binary, description) ->
         offsetCounter += separatorSize
         PartDescriptor {
@@ -55,46 +54,45 @@ public fun EnvelopeBuilder.multipart(
 
     meta {
         if (separator != DEFAULT_MULTIPART_DATA_SEPARATOR) {
-            SEPARATOR_KEY put separator
+            SEPARATOR_KEY put separator.decodeToString()
         }
         setIndexed(PARTS_KEY, partDescriptors.map { it.toMeta() })
     }
 
     data {
         parts.forEach {
-            writeRawString(separator)
+            write(separator)
             writeBinary(it.binary)
         }
     }
 }
 
+/**
+ * Put a list of envelopes as parts of given envelope
+ */
 public fun EnvelopeBuilder.envelopes(
     envelopes: List<Envelope>,
-    format: EnvelopeFormat = TaggedEnvelopeFormat,
-    separator: String = DEFAULT_MULTIPART_DATA_SEPARATOR
+    separator: ByteString = DEFAULT_MULTIPART_DATA_SEPARATOR,
 ) {
     val parts = envelopes.map {
-        val binary = format.toBinary(it)
+        val binary = Binary(it, TaggedEnvelopeFormat)
         EnvelopePart(binary, null)
     }
-    meta{
-        set(MULTIPART_KEY + PART_FORMAT_KEY, format.toMeta())
-    }
     multipart(parts, separator)
 }
 
 public fun Envelope.parts(): EnvelopeParts {
     if (data == null) return emptyList()
     //TODO add zip folder reader
-    val parts = meta.getIndexed(PARTS_KEY).values.mapNotNull { it.node }.map {
+    val parts = meta.getIndexed(PARTS_KEY).values.map {
         PartDescriptor.read(it)
     }
     return if (parts.isEmpty()) {
-        listOf(EnvelopePart(data!!, meta[MULTIPART_KEY].node))
+        listOf(EnvelopePart(data!!, meta[MULTIPART_KEY]))
     } else {
         parts.map {
             val binary = data!!.view(it.offset, it.size)
-            val meta = Laminate(it.partMeta, meta[MULTIPART_KEY].node)
+            val meta = Laminate(it.partMeta, meta[MULTIPART_KEY])
             EnvelopePart(binary, meta)
         }
     }
@@ -107,14 +105,4 @@ public val EnvelopePart.name: String? get() = description?.get("name").string
 /**
  * Represent envelope part by an envelope
  */
-public fun EnvelopePart.envelope(plugin: IOPlugin): Envelope {
-    val formatItem = description?.get(PART_FORMAT_KEY)
-    return if (formatItem != null) {
-        val format: EnvelopeFormat = plugin.resolveEnvelopeFormat(formatItem)
-            ?: error("Envelope format for $formatItem is not resolved")
-        binary.readWith(format)
-    } else {
-        error("Envelope description not found")
-        //SimpleEnvelope(description ?: Meta.EMPTY, binary)
-    }
-}
+public fun EnvelopePart.envelope(): Envelope = binary.readWith(TaggedEnvelopeFormat)

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

@@ -1,135 +1,118 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.*
+import kotlinx.io.Sink
+import kotlinx.io.Source
+import kotlinx.io.readByteArray
 import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.context.Factory
-import space.kscience.dataforge.io.IOFormat.Companion.NAME_KEY
 import space.kscience.dataforge.io.IOFormatFactory.Companion.IO_FORMAT_TYPE
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.MetaItemValue
-import space.kscience.dataforge.meta.MetaRepr
+import space.kscience.dataforge.misc.DfId
 import space.kscience.dataforge.misc.Named
-import space.kscience.dataforge.misc.Type
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
-import space.kscience.dataforge.values.Value
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
 /**
- * And interface for reading and writing objects into with IO streams
+ * Reader of a custom object from input
  */
-public interface IOFormat<T : Any> : MetaRepr {
+public interface IOReader<out T> {
+    /**
+     * The type of object being read
+     */
     public val type: KType
 
-    public fun writeObject(output: Output, obj: T)
-    public fun readObject(input: Input): T
+    public fun readFrom(source: Source): T
+
+    public fun readFrom(binary: Binary): T = binary.read { readFrom(this) }
 
     public companion object {
-        public val NAME_KEY: Name = "name".asName()
-        public val META_KEY: Name = "meta".asName()
+        /**
+         * 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()
+
+            override fun readFrom(binary: Binary): Binary = binary
+        }
     }
 }
 
-public fun <T : Any> Input.readWith(format: IOFormat<T>): T = format.readObject(this@readWith)
+public inline fun <reified T> IOReader(crossinline read: Source.() -> T): IOReader<T> = object : IOReader<T> {
+    override val type: KType = typeOf<T>()
 
-public fun <T: Any> IOFormat<T>.readObject(binary: Binary): T = binary.read {
-    readObject(this)
+    override fun readFrom(source: Source): T = source.read()
+}
+
+public fun interface IOWriter<in T> {
+    public fun writeTo(sink: Sink, obj: T)
 }
 
 /**
- * Read given binary as object using given format
+ * And interface for reading and writing objects into with IO streams
  */
-public fun <T : Any> Binary.readWith(format: IOFormat<T>): T = read {
+public interface IOFormat<T> : IOReader<T>, IOWriter<T>
+
+public fun <T : Any> 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 : Any> Output.writeWith(format: IOFormat<T>, obj: T): Unit =
-    format.run { writeObject(this@writeWith, obj) }
+/**
+ * Write an object to the [Sink] with given [format]
+ */
+public fun <T : Any> Sink.writeWith(format: IOWriter<T>, obj: T): Unit =
+    format.writeTo(this, obj)
 
-public inline fun <reified T : Any> IOFormat.Companion.listOf(
-    format: IOFormat<T>,
-): IOFormat<List<T>> = object : IOFormat<List<T>> {
-    override val type: KType = typeOf<List<T>>()
 
-    override fun writeObject(output: Output, obj: List<T>) {
-        output.writeInt(obj.size)
-        format.run {
-            obj.forEach {
-                writeObject(output, it)
-            }
-        }
-    }
-
-    override fun readObject(input: Input): List<T> {
-        val size = input.readInt()
-        return format.run {
-            List(size) { readObject(input) }
-        }
-    }
-
-    override fun toMeta(): Meta = Meta {
-        NAME_KEY put "list"
-        "contentFormat" put format.toMeta()
-    }
-
-}
-
-//public fun ObjectPool<Buffer>.fill(block: Buffer.() -> Unit): Buffer {
-//    val buffer = borrow()
-//    return try {
-//        buffer.apply(block)
-//    } catch (ex: Exception) {
-//        //recycle(buffer)
-//        throw ex
-//    }
-//}
-
-@Type(IO_FORMAT_TYPE)
-public interface IOFormatFactory<T : Any> : Factory<IOFormat<T>>, Named, MetaRepr {
+@DfId(IO_FORMAT_TYPE)
+public interface IOFormatFactory<T : Any> : Factory<IOFormat<T>>, Named {
     /**
      * Explicit type for dynamic type checks
      */
     public val type: KType
 
-    override fun toMeta(): Meta = Meta {
-        NAME_KEY put name.toString()
-    }
-
     public companion object {
         public const val IO_FORMAT_TYPE: String = "io.format"
+        public val NAME_KEY: Name = "name".asName()
+        public val META_KEY: Name = "meta".asName()
     }
 }
 
-public fun <T : Any> IOFormat<T>.toBinary(obj: T): Binary = Binary { writeObject(this, obj) }
+public fun <T : Any> 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
+
+    override val name: Name = "float32".asName()
+
+    override val type: KType get() = typeOf<Float>()
+
+    override fun writeTo(sink: Sink, obj: Float) {
+        sink.writeFloat(obj)
+    }
+
+    override fun readFrom(source: Source): Float = source.readFloat()
+}
+
 
 public object DoubleIOFormat : IOFormat<Double>, IOFormatFactory<Double> {
-    override fun invoke(meta: Meta, context: Context): IOFormat<Double> = this
+    override fun build(context: Context, meta: Meta): IOFormat<Double> = this
 
-    override val name: Name = "double".asName()
+    override val name: Name = "float64".asName()
 
     override val type: KType get() = typeOf<Double>()
 
-    override fun writeObject(output: Output, obj: kotlin.Double) {
-        output.writeDouble(obj)
+    override fun writeTo(sink: Sink, obj: Double) {
+        sink.writeLong(obj.toBits())
     }
 
-    override fun readObject(input: Input): Double = input.readDouble()
-}
-
-public object ValueIOFormat : IOFormat<Value>, IOFormatFactory<Value> {
-    override fun invoke(meta: Meta, context: Context): IOFormat<Value> = this
-
-    override val name: Name = "value".asName()
-
-    override val type: KType get() = typeOf<Value>()
-
-    override fun writeObject(output: Output, obj: Value) {
-        BinaryMetaFormat.run { output.writeValue(obj) }
-    }
-
-    override fun readObject(input: Input): Value {
-        return (BinaryMetaFormat.run { input.readMetaItem() } as? MetaItemValue)?.value
-            ?: error("The item is not a value")
-    }
+    override fun readFrom(source: Source): Double = source.readDouble()
 }

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

@@ -2,14 +2,15 @@ package space.kscience.dataforge.io
 
 import space.kscience.dataforge.context.*
 import space.kscience.dataforge.io.EnvelopeFormatFactory.Companion.ENVELOPE_FORMAT_TYPE
-import space.kscience.dataforge.io.IOFormat.Companion.META_KEY
-import space.kscience.dataforge.io.IOFormat.Companion.NAME_KEY
 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.*
+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.names.Name
-import space.kscience.dataforge.names.toName
-import kotlin.reflect.KClass
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
 
 public class IOPlugin(meta: Meta) : AbstractPlugin(meta) {
     override val tag: PluginTag get() = Companion.tag
@@ -18,15 +19,14 @@ public class IOPlugin(meta: Meta) : AbstractPlugin(meta) {
         context.gather<IOFormatFactory<*>>(IO_FORMAT_TYPE).values
     }
 
-    public fun <T : Any> resolveIOFormat(item: MetaItem, type: KClass<out T>): IOFormat<T>? {
-        val key = item.string ?: item.node[NAME_KEY]?.string ?: error("Format name not defined")
-        val name = key.toName()
-        return ioFormatFactories.find { it.name == name }?.let {
-            @Suppress("UNCHECKED_CAST")
-            if (it.type != type) error("Format type ${it.type} is not the same as requested type $type")
-            else it.invoke(item.node[META_KEY].node ?: Meta.EMPTY, context) as IOFormat<T>
-        }
-    }
+    @Suppress("UNCHECKED_CAST")
+    @DFInternal
+    public fun <T : Any> 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>? =
+        resolveIOFormat(typeOf<T>(), meta)
 
 
     public val metaFormatFactories: Collection<MetaFormatFactory> by lazy {
@@ -34,41 +34,53 @@ public class IOPlugin(meta: Meta) : AbstractPlugin(meta) {
     }
 
     public fun resolveMetaFormat(key: Short, meta: Meta = Meta.EMPTY): MetaFormat? =
-        metaFormatFactories.find { it.key == key }?.invoke(meta)
+        metaFormatFactories.find { it.key == key }?.build(context, meta)
 
     public fun resolveMetaFormat(name: String, meta: Meta = Meta.EMPTY): MetaFormat? =
-        metaFormatFactories.find { it.shortName == name }?.invoke(meta)
+        metaFormatFactories.find { it.shortName == name }?.build(context, meta)
 
     public val envelopeFormatFactories: Collection<EnvelopeFormatFactory> by lazy {
         context.gather<EnvelopeFormatFactory>(ENVELOPE_FORMAT_TYPE).values
     }
 
     private fun resolveEnvelopeFormat(name: Name, meta: Meta = Meta.EMPTY): EnvelopeFormat? =
-        envelopeFormatFactories.find { it.name == name }?.invoke(meta, context)
+        envelopeFormatFactories.find { it.name == name }?.build(context, meta)
 
-    public fun resolveEnvelopeFormat(item: MetaItem): EnvelopeFormat? {
-        val name = item.string ?: item.node[NAME_KEY]?.string ?: error("Envelope format name not defined")
-        val meta = item.node[META_KEY].node ?: Meta.EMPTY
-        return resolveEnvelopeFormat(name.toName(), meta)
+    public fun resolveEnvelopeFormat(item: Meta): EnvelopeFormat? {
+        val name = item.string ?: item[IOFormatFactory.NAME_KEY]?.string ?: error("Envelope format name not defined")
+        val meta = item[IOFormatFactory.META_KEY] ?: Meta.EMPTY
+        return resolveEnvelopeFormat(Name.parse(name), meta)
     }
 
-    override fun content(target: String): Map<Name, Any> {
-        return when (target) {
-            META_FORMAT_TYPE -> defaultMetaFormats.toMap()
-            ENVELOPE_FORMAT_TYPE -> defaultEnvelopeFormats.toMap()
-            else -> super.content(target)
-        }
+    override fun content(target: String): Map<Name, Any> = when (target) {
+        META_FORMAT_TYPE -> defaultMetaFormats.associateByName()
+        ENVELOPE_FORMAT_TYPE -> defaultEnvelopeFormats.associateByName()
+        IO_FORMAT_TYPE -> content(META_FORMAT_TYPE) + content(ENVELOPE_FORMAT_TYPE)
+        else -> super.content(target)
     }
 
     public companion object : PluginFactory<IOPlugin> {
-        public val defaultMetaFormats: List<MetaFormatFactory> = listOf(JsonMetaFormat, BinaryMetaFormat)
-        public val defaultEnvelopeFormats: List<EnvelopeFormatFactory> = listOf(TaggedEnvelopeFormat, TaglessEnvelopeFormat)
+        public val defaultMetaFormats: List<MetaFormatFactory> = listOf(JsonMetaFormat)
+        public val defaultEnvelopeFormats: List<EnvelopeFormatFactory> = listOf(
+            TaggedEnvelopeFormat,
+            TaglessEnvelopeFormat
+        )
 
         override val tag: PluginTag = PluginTag("io", group = PluginTag.DATAFORGE_GROUP)
 
-        override val type: KClass<out IOPlugin> = IOPlugin::class
-        override fun invoke(meta: Meta, context: Context): IOPlugin = IOPlugin(meta)
+        override fun build(context: Context, meta: Meta): IOPlugin = IOPlugin(meta)
+
+        public val WORK_DIRECTORY_KEY: Name = Name.of("io", "workDirectory")
     }
 }
 
-public val Context.io: IOPlugin get() = plugins.fetch(IOPlugin)
+internal val ioContext = Context("IO") {
+    plugin(IOPlugin)
+}
+
+public val Context.io: IOPlugin
+    get() = if (this == Global) {
+        ioContext.request(IOPlugin)
+    } else {
+        request(IOPlugin)
+    }

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

@@ -1,59 +1,48 @@
-@file:Suppress("UNUSED_PARAMETER")
-
 package space.kscience.dataforge.io
 
 
-import io.ktor.utils.io.core.Input
-import io.ktor.utils.io.core.Output
+import kotlinx.io.Sink
+import kotlinx.io.Source
+import kotlinx.io.readString
+import kotlinx.io.writeString
 import kotlinx.serialization.json.Json
-import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonElement
 import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.io.IOFormat.Companion.NAME_KEY
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.descriptors.NodeDescriptor
-import space.kscience.dataforge.meta.node
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
 import space.kscience.dataforge.meta.toJson
-import space.kscience.dataforge.meta.toMetaItem
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
+import space.kscience.dataforge.meta.toMeta
 
 /**
  * A Json format for Meta representation
  */
 public class JsonMetaFormat(private val json: Json = DEFAULT_JSON) : MetaFormat {
 
-    override val type: KType get() = typeOf<Meta>()
-
-    override fun writeMeta(output: Output, meta: Meta, descriptor: NodeDescriptor?) {
-        val jsonObject = meta.toJson(descriptor)
-        output.writeUtf8String(json.encodeToString(JsonObject.serializer(), jsonObject))
+    override fun writeMeta(sink: Sink, meta: Meta, descriptor: MetaDescriptor?) {
+        val jsonElement = meta.toJson(descriptor)
+        sink.writeString(json.encodeToString(JsonElement.serializer(), jsonElement))
     }
 
-    override fun toMeta(): Meta = Meta {
-        NAME_KEY put name.toString()
-    }
-
-    override fun readMeta(input: Input, descriptor: NodeDescriptor?): Meta {
-        val str = input.readUtf8String()//readByteArray().decodeToString()
+    override fun readMeta(source: Source, descriptor: MetaDescriptor?): Meta {
+        val str = source.readString()
         val jsonElement = json.parseToJsonElement(str)
-        val item = jsonElement.toMetaItem(descriptor)
-        return item.node ?: Meta.EMPTY
+        return jsonElement.toMeta(descriptor)
     }
 
     public companion object : MetaFormatFactory {
         public val DEFAULT_JSON: Json = Json { prettyPrint = true }
 
-        override fun invoke(meta: Meta, context: Context): MetaFormat = default
+        override fun build(context: Context, meta: Meta): MetaFormat = default
 
         override val shortName: String = "json"
         override val key: Short = 0x4a53//"JS"
 
         private val default = JsonMetaFormat()
 
-        override fun writeMeta(output: Output, meta: Meta, descriptor: NodeDescriptor?): Unit =
-            default.run { writeMeta(output, meta, descriptor) }
+        override fun writeMeta(sink: Sink, meta: Meta, descriptor: MetaDescriptor?): Unit =
+            default.run { writeMeta(sink, meta, descriptor) }
 
-        override fun readMeta(input: Input, descriptor: NodeDescriptor?): Meta =
-            default.run { readMeta(input, descriptor) }
+        override fun readMeta(source: Source, descriptor: MetaDescriptor?): Meta =
+            default.run { readMeta(source, descriptor) }
     }
 }

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

@@ -1,14 +1,15 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.ByteReadPacket
-import io.ktor.utils.io.core.Input
-import io.ktor.utils.io.core.Output
-import io.ktor.utils.io.core.use
+
+import kotlinx.io.Sink
+import kotlinx.io.Source
+import kotlinx.io.buffered
 import space.kscience.dataforge.context.Context
+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.NodeDescriptor
-import space.kscience.dataforge.misc.Type
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.misc.DfId
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.asName
 import space.kscience.dataforge.names.plus
@@ -19,24 +20,25 @@ import kotlin.reflect.typeOf
  * A format for meta serialization
  */
 public interface MetaFormat : IOFormat<Meta> {
+
     override val type: KType get() = typeOf<Meta>()
 
-    override fun writeObject(output: Output, obj: Meta) {
-        writeMeta(output, obj, null)
+    override fun writeTo(sink: Sink, obj: Meta) {
+        writeMeta(sink, obj, null)
     }
 
-    override fun readObject(input: Input): Meta = readMeta(input)
+    override fun readFrom(source: Source): Meta = readMeta(source)
 
     public fun writeMeta(
-        output: Output,
+        sink: Sink,
         meta: Meta,
-        descriptor: NodeDescriptor? = null,
+        descriptor: MetaDescriptor? = null,
     )
 
-    public fun readMeta(input: Input, descriptor: NodeDescriptor? = null): Meta
+    public fun readMeta(source: Source, descriptor: MetaDescriptor? = null): Meta
 }
 
-@Type(META_FORMAT_TYPE)
+@DfId(META_FORMAT_TYPE)
 public interface MetaFormatFactory : IOFormatFactory<Meta>, MetaFormat {
     public val shortName: String
 
@@ -46,25 +48,23 @@ public interface MetaFormatFactory : IOFormatFactory<Meta>, MetaFormat {
 
     public val key: Short get() = name.hashCode().toShort()
 
-    override operator fun invoke(meta: Meta, context: Context): MetaFormat
+    override fun build(context: Context, meta: Meta): MetaFormat
 
     public companion object {
         public const val META_FORMAT_TYPE: String = "io.format.meta"
     }
 }
 
-public fun Meta.toString(format: MetaFormat): String = buildByteArray {
+public fun Meta.toString(format: MetaFormat): String = ByteArray {
     format.run {
-        writeObject(this@buildByteArray, this@toString)
+        writeTo(this@ByteArray, this@toString)
     }
 }.decodeToString()
 
-public fun Meta.toString(formatFactory: MetaFormatFactory): String = toString(formatFactory())
+public fun Meta.toString(formatFactory: MetaFormatFactory): String = toString(formatFactory.build(Global, Meta.EMPTY))
 
-public fun MetaFormat.parse(str: String): Meta {
-    return ByteReadPacket(str.encodeToByteArray()).use { readObject(it) }
-}
+public fun MetaFormat.parse(str: String): Meta = readFrom(StringSource(str).buffered())
 
-public fun MetaFormatFactory.parse(str: String, formatMeta: Meta): Meta = invoke(formatMeta).parse(str)
+public fun MetaFormatFactory.parse(str: String, formatMeta: Meta): Meta = build(Global, formatMeta).parse(str)
 
 

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

@@ -1,16 +1,16 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.*
+import kotlinx.io.*
+import kotlinx.io.bytestring.decodeToString
 import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.io.IOFormat.Companion.META_KEY
-import space.kscience.dataforge.io.IOFormat.Companion.NAME_KEY
+import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.enum
 import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.string
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.plus
-import space.kscience.dataforge.names.toName
+
 
 /**
  * A streaming-friendly envelope format with a short binary tag.
@@ -19,79 +19,79 @@ import space.kscience.dataforge.names.toName
 public class TaggedEnvelopeFormat(
     public val io: IOPlugin,
     public val version: VERSION = VERSION.DF02,
+    public val metaFormatFactory: MetaFormatFactory = JsonMetaFormat,
 ) : EnvelopeFormat {
 
 //    private val metaFormat = io.metaFormat(metaFormatKey)
 //        ?: error("Meta format with key $metaFormatKey could not be resolved in $io")
 
 
-    private fun Tag.toBinary() = Binary(24) {
-        writeRawString(START_SEQUENCE)
-        writeRawString(version.name)
+    private fun Tag.toBinary() = Binary {
+        write(START_SEQUENCE)
+        writeString(version.name)
         writeShort(metaFormatKey)
         writeUInt(metaSize)
         when (version) {
             VERSION.DF02 -> {
                 writeUInt(dataSize.toUInt())
             }
+
             VERSION.DF03 -> {
                 writeULong(dataSize)
             }
         }
-        writeRawString(END_SEQUENCE)
+        write(END_SEQUENCE)
     }
 
-    override fun writeEnvelope(
-        output: Output,
-        envelope: Envelope,
-        metaFormatFactory: MetaFormatFactory,
-        formatMeta: Meta,
+    override fun writeTo(
+        sink: Sink,
+        obj: Envelope,
     ) {
-        val metaFormat = metaFormatFactory.invoke(formatMeta, this@TaggedEnvelopeFormat.io.context)
-        val metaBytes = metaFormat.toBinary(envelope.meta)
-        val actualSize: ULong = (envelope.data?.size ?: 0).toULong()
+        val metaFormat = metaFormatFactory.build(io.context, Meta.EMPTY)
+        val metaBytes = Binary(obj.meta, metaFormat)
+        val actualSize: ULong = (obj.data?.size ?: 0).toULong()
         val tag = Tag(metaFormatFactory.key, metaBytes.size.toUInt() + 2u, actualSize)
-        output.writeBinary(tag.toBinary())
-        output.writeBinary(metaBytes)
-        output.writeRawString("\r\n")
-        envelope.data?.let {
-            output.writeBinary(it)
+        sink.writeBinary(tag.toBinary())
+        sink.writeBinary(metaBytes)
+        sink.writeString("\r\n")
+        obj.data?.let {
+            sink.writeBinary(it)
         }
     }
 
     /**
      * Read an envelope from input into memory
      *
-     * @param input an input to read from
+     * @param source an input to read from
      * @param formats a collection of meta formats to resolve
      */
-    override fun readObject(input: Input): Envelope {
-        val tag = input.readTag(this.version)
+    override fun readFrom(source: Source): Envelope {
+        val tag = source.readTag(this.version)
 
         val metaFormat = io.resolveMetaFormat(tag.metaFormatKey)
             ?: error("Meta format with key ${tag.metaFormatKey} not found")
 
-        val metaBinary = input.readBinary(tag.metaSize.toInt())
+        val metaBinary = source.readBinary(tag.metaSize.toInt())
 
-        val meta: Meta = metaFormat.readObject(metaBinary)
+        val meta: Meta = metaFormat.readFrom(metaBinary)
 
-        val data = input.readBinary(tag.dataSize.toInt())
+        val data = source.readBinary(tag.dataSize.toInt())
 
         return SimpleEnvelope(meta, data)
     }
 
-    override fun readPartial(input: Input): PartialEnvelope {
-        val tag = input.readTag(this.version)
+    override fun readFrom(binary: Binary): Envelope = binary.read {
+        val tag = readTag(version)
 
         val metaFormat = io.resolveMetaFormat(tag.metaFormatKey)
             ?: error("Meta format with key ${tag.metaFormatKey} not found")
 
-        val metaBinary = input.readBinary(tag.metaSize.toInt())
+        val metaBinary = readBinary(tag.metaSize.toInt())
 
-        val meta: Meta = metaFormat.readObject(metaBinary)
+        val meta: Meta = metaFormat.readFrom(metaBinary)
 
 
-        return PartialEnvelope(meta, version.tagSize + tag.metaSize, tag.dataSize)
+        SimpleEnvelope(meta, binary.view((version.tagSize + tag.metaSize).toInt(), tag.dataSize.toInt()))
     }
 
     private data class Tag(
@@ -105,23 +105,16 @@ public class TaggedEnvelopeFormat(
         DF03(24u)
     }
 
-    override fun toMeta(): Meta = Meta {
-        NAME_KEY put name.toString()
-        META_KEY put {
-            "version" put version
-        }
-    }
-
     public companion object : EnvelopeFormatFactory {
-        private const val START_SEQUENCE = "#~"
-        private const val END_SEQUENCE = "~#\r\n"
+        private val START_SEQUENCE = "#~".toAsciiByteString()
+        private val END_SEQUENCE = "~#\r\n".toAsciiByteString()
 
-        override val name: Name = super.name + "tagged"
+        override val name: Name = EnvelopeFormatFactory.ENVELOPE_FACTORY_NAME + "tagged"
 
-        override fun invoke(meta: Meta, context: Context): EnvelopeFormat {
+        override fun build(context: Context, meta: Meta): EnvelopeFormat {
             val io = context.io
 
-            val metaFormatName = meta["name"].string?.toName() ?: JsonMetaFormat.name
+            val metaFormatName = meta["name"].string?.let { Name.parse(it) } ?: JsonMetaFormat.name
             //Check if appropriate factory exists
             io.metaFormatFactories.find { it.name == metaFormatName } ?: error("Meta format could not be resolved")
 
@@ -130,57 +123,48 @@ public class TaggedEnvelopeFormat(
             return TaggedEnvelopeFormat(io, version)
         }
 
-        private fun Input.readTag(version: VERSION): Tag {
-            val start = readRawString(2)
+        private fun Source.readTag(version: VERSION): Tag {
+            val start = readByteString(2)
             if (start != START_SEQUENCE) error("The input is not an envelope")
-            val versionString = readRawString(4)
-            if (version.name != versionString) error("Wrong version of DataForge: expected $version but found $versionString")
+            val versionString = readByteString(4)
+            if (version.name.toAsciiByteString() != versionString) error("Wrong version of DataForge: expected $version but found $versionString")
             val metaFormatKey = readShort()
             val metaLength = readUInt()
             val dataLength: ULong = when (version) {
                 VERSION.DF02 -> readUInt().toULong()
                 VERSION.DF03 -> readULong()
             }
-            val end = readRawString(4)
+            val end = readByteString(4)
             if (end != END_SEQUENCE) error("The input is not an envelope")
             return Tag(metaFormatKey, metaLength, dataLength)
         }
 
-        override fun peekFormat(io: IOPlugin, binary: Binary): EnvelopeFormat? {
-            return try {
-                binary.read{
-                    val header = readRawString(6)
-                    return@read when (header.substring(2..5)) {
-                        VERSION.DF02.name -> TaggedEnvelopeFormat(io, VERSION.DF02)
-                        VERSION.DF03.name -> TaggedEnvelopeFormat(io, VERSION.DF03)
-                        else -> null
-                    }
+        override fun peekFormat(io: IOPlugin, binary: Binary): EnvelopeFormat? = try {
+            binary.read {
+                val header = readByteString(6)
+                when (header.substring(2, 6).decodeToString()) {
+                    VERSION.DF02.name -> TaggedEnvelopeFormat(io, VERSION.DF02)
+                    VERSION.DF03.name -> TaggedEnvelopeFormat(io, VERSION.DF03)
+                    else -> null
                 }
-            } catch (ex: Exception) {
-                null
             }
+        } catch (ex: Exception) {
+            null
         }
 
-        private val default by lazy { invoke() }
+        private val default by lazy { build(Global, Meta.EMPTY) }
 
-        override fun readPartial(input: Input): PartialEnvelope =
-            default.run { readPartial(input) }
+        override fun readFrom(binary: Binary): Envelope =
+            default.run { readFrom(binary) }
 
-        override fun writeEnvelope(
-            output: Output,
-            envelope: Envelope,
-            metaFormatFactory: MetaFormatFactory,
-            formatMeta: Meta,
+        override fun writeTo(
+            sink: Sink,
+            obj: Envelope,
         ): Unit = default.run {
-            writeEnvelope(
-                output,
-                envelope,
-                metaFormatFactory,
-                formatMeta
-            )
+            writeTo(sink, obj)
         }
 
-        override fun readObject(input: Input): Envelope = default.readObject(input)
+        override fun readFrom(source: Source): Envelope = default.readFrom(source)
     }
 
 }

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

@@ -1,175 +1,104 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.*
+
+import kotlinx.io.*
+import kotlinx.io.bytestring.ByteString
+import kotlinx.io.bytestring.encodeToByteString
 import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.io.IOFormat.Companion.META_KEY
-import space.kscience.dataforge.io.IOFormat.Companion.NAME_KEY
+import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.isEmpty
-import space.kscience.dataforge.meta.string
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.asName
-import kotlin.collections.set
+import space.kscience.dataforge.names.plus
 
 /**
- * A text envelope format with human-readable tag.
+ * A text envelope format based on block separators.
  * TODO add description
  */
 public class TaglessEnvelopeFormat(
     public val io: IOPlugin,
     public val meta: Meta = Meta.EMPTY,
+    public val metaFormatFactory: MetaFormatFactory = JsonMetaFormat,
 ) : EnvelopeFormat {
 
-    private val metaStart = meta[META_START_PROPERTY].string ?: DEFAULT_META_START
-    private val dataStart = meta[DATA_START_PROPERTY].string ?: DEFAULT_DATA_START
+//    private val metaStart = meta[META_START_PROPERTY].string ?: DEFAULT_META_START
+//    private val dataStart = meta[DATA_START_PROPERTY].string ?: DEFAULT_DATA_START
 
-    private fun Output.writeProperty(key: String, value: Any) {
-        writeFully("#? $key: $value;\r\n".encodeToByteArray())
-    }
+//    private fun Output.writeProperty(key: String, value: Any) {
+//        writeFully("#? $key: $value;\r\n".encodeToByteArray())
+//    }
 
-    override fun writeEnvelope(
-        output: Output,
-        envelope: Envelope,
-        metaFormatFactory: MetaFormatFactory,
-        formatMeta: Meta
+    override fun writeTo(
+        sink: Sink,
+        obj: Envelope,
     ) {
-        val metaFormat = metaFormatFactory(formatMeta, this.io.context)
+        val metaFormat = metaFormatFactory.build(this.io.context, meta)
 
         //printing header
-        output.writeRawString(TAGLESS_ENVELOPE_HEADER + "\r\n")
-
-        //printing all properties
-        output.writeProperty(META_TYPE_PROPERTY,
-            metaFormatFactory.shortName)
-        //TODO add optional metaFormat properties
-        val actualSize: Int = envelope.data?.size ?: 0
-
-        output.writeProperty(DATA_LENGTH_PROPERTY, actualSize)
+        sink.write(TAGLESS_ENVELOPE_HEADER)
+        sink.writeString("\r\n")
 
         //Printing meta
-        if (!envelope.meta.isEmpty()) {
-            val metaBytes = metaFormat.toBinary(envelope.meta)
-            output.writeProperty(META_LENGTH_PROPERTY,
-                metaBytes.size + 2)
-            output.writeUtf8String(this.metaStart + "\r\n")
-            output.writeBinary(metaBytes)
-            output.writeRawString("\r\n")
+        if (!obj.meta.isEmpty()) {
+            val metaBinary = Binary(obj.meta, metaFormat)
+            sink.writeString(META_START + "-${metaFormatFactory.shortName}\r\n")
+            sink.writeBinary(metaBinary)
+            sink.writeString("\r\n")
         }
 
         //Printing data
-        envelope.data?.let { data ->
-            output.writeUtf8String(this.dataStart + "\r\n")
-            output.writeBinary(data)
+        obj.data?.let { data ->
+            //val actualSize: Int = envelope.data?.size ?: 0
+            sink.writeString(DATA_START + "\r\n")
+            sink.writeBinary(data)
         }
     }
 
-    override fun readObject(input: Input): Envelope {
-        var line: String
-        do {
-            line = input.readSafeUtf8Line() // ?: error("Input does not contain tagless envelope header")
-        } while (!line.startsWith(TAGLESS_ENVELOPE_HEADER))
-        val properties = HashMap<String, String>()
-
-        line = ""
-        while (line.isBlank() || line.startsWith("#?")) {
-            if (line.startsWith("#?")) {
-                val match = propertyPattern.find(line)
-                    ?: error("Line $line does not match property declaration pattern")
-                val (key, value) = match.destructured
-                properties[key] = value
-            }
-            //If can't read line, return envelope without data
-            if (input.endOfInput) return SimpleEnvelope(Meta.EMPTY, null)
-            line = input.readSafeUtf8Line()
-        }
+    override fun readFrom(source: Source): Envelope {
+        //read preamble
+        source.discardWithSeparator(
+            TAGLESS_ENVELOPE_HEADER,
+            atMost = 1024,
+        )
 
         var meta: Meta = Meta.EMPTY
 
-        if (line.startsWith(metaStart)) {
-            val metaFormat = properties[META_TYPE_PROPERTY]?.let { io.resolveMetaFormat(it) } ?: JsonMetaFormat
-            val metaSize = properties[META_LENGTH_PROPERTY]?.toInt()
-            meta = if (metaSize != null) {
-                metaFormat.readObject(input.readBinary(metaSize))
-            } else {
-                metaFormat.readObject(input)
+        var data: Binary? = null
+
+        source.discardWithSeparator(
+            SEPARATOR_PREFIX,
+            atMost = 1024,
+        )
+
+        var header: String = ByteArray {
+            source.readWithSeparatorTo(this, "\n".encodeToByteString())
+        }.decodeToString()
+
+        while (!source.exhausted()) {
+            val block = ByteArray {
+                source.readWithSeparatorTo(this, SEPARATOR_PREFIX)
             }
+
+            val nextHeader = ByteArray {
+                source.readWithSeparatorTo(this, "\n".encodeToByteString())
+            }.decodeToString()
+
+            //terminate on end
+            if (header.startsWith("END")) break
+
+
+            if (header.startsWith("META")) {
+                //TODO check format
+                val metaFormat: MetaFormatFactory = JsonMetaFormat
+                meta = metaFormat.readMeta(ByteArraySource(block).buffered())
+            }
+
+            if (header.startsWith("DATA")) {
+                data = block.asBinary()
+            }
+            header = nextHeader
         }
-
-        do {
-            try {
-                line = input.readSafeUtf8Line()
-            } catch (ex: EOFException) {
-                //returning an Envelope without data if end of input is reached
-                return SimpleEnvelope(meta, null)
-            }
-        } while (!line.startsWith(dataStart))
-
-        val data: Binary = if (properties.containsKey(DATA_LENGTH_PROPERTY)) {
-            input.readBinary(properties[DATA_LENGTH_PROPERTY]!!.toInt())
-//            val bytes = ByteArray(properties[DATA_LENGTH_PROPERTY]!!.toInt())
-//            readByteArray(bytes)
-//            bytes.asBinary()
-        } else {
-            Binary {
-                input.copyTo(this)
-            }
-        }
-
-        return SimpleEnvelope(meta, data)
-    }
-
-    override fun readPartial(input: Input): PartialEnvelope {
-        var offset = 0u
-        var line: String
-        do {
-            line = input.readSafeUtf8Line()// ?: error("Input does not contain tagless envelope header")
-            offset += line.encodeToByteArray().size.toUInt()
-        } while (!line.startsWith(TAGLESS_ENVELOPE_HEADER))
-        val properties = HashMap<String, String>()
-
-        line = ""
-        while (line.isBlank() || line.startsWith("#?")) {
-            if (line.startsWith("#?")) {
-                val match = propertyPattern.find(line)
-                    ?: error("Line $line does not match property declaration pattern")
-                val (key, value) = match.destructured
-                properties[key] = value
-            }
-            try {
-                line = input.readSafeUtf8Line()
-                offset += line.encodeToByteArray().size.toUInt()
-            } catch (ex: EOFException) {
-                return PartialEnvelope(Meta.EMPTY, offset.toUInt(), 0.toULong())
-            }
-        }
-
-        var meta: Meta = Meta.EMPTY
-
-        if (line.startsWith(metaStart)) {
-            val metaFormat = properties[META_TYPE_PROPERTY]?.let { io.resolveMetaFormat(it) } ?: JsonMetaFormat
-            val metaSize = properties[META_LENGTH_PROPERTY]?.toInt()
-            meta = if (metaSize != null) {
-                offset += metaSize.toUInt()
-                metaFormat.readObject(input.readBinary(metaSize))
-            } else {
-                error("Can't partially read an envelope with undefined meta size")
-            }
-        }
-
-        do {
-            line = input.readSafeUtf8Line() //?: return PartialEnvelope(Meta.EMPTY, offset.toUInt(), 0.toULong())
-            offset += line.encodeToByteArray().size.toUInt()
-            //returning an Envelope without data if end of input is reached
-        } while (!line.startsWith(dataStart))
-
-        val dataSize = properties[DATA_LENGTH_PROPERTY]?.toULong()
-        return PartialEnvelope(meta, offset, dataSize)
-    }
-
-    override fun toMeta(): Meta = Meta {
-        NAME_KEY put name.toString()
-        META_KEY put meta
+        return Envelope(meta, data)
     }
 
     public companion object : EnvelopeFormatFactory {
@@ -183,45 +112,41 @@ public class TaglessEnvelopeFormat(
 
         public const val TAGLESS_ENVELOPE_TYPE: String = "tagless"
 
-        public const val TAGLESS_ENVELOPE_HEADER: String = "#~DFTL~#"
-        public const val META_START_PROPERTY: String = "metaSeparator"
-        public const val DEFAULT_META_START: String = "#~META~#"
-        public const val DATA_START_PROPERTY: String = "dataSeparator"
-        public const val DEFAULT_DATA_START: String = "#~DATA~#"
+        public val SEPARATOR_PREFIX: ByteString = "\n#~".encodeToByteString()
+
+        public val TAGLESS_ENVELOPE_HEADER: ByteString = "#~DFTL".encodeToByteString()
+
+        //        public const val META_START_PROPERTY: String = "metaSeparator"
+        public const val META_START: String = "#~META"
+
+        //        public const val DATA_START_PROPERTY: String = "dataSeparator"
+        public const val DATA_START: String = "#~DATA"
+
+        public const val END: String = "#~END"
 
         public const val code: Int = 0x4446544c //DFTL
 
-        override val name: Name = TAGLESS_ENVELOPE_TYPE.asName()
+        override val name: Name = EnvelopeFormatFactory.ENVELOPE_FACTORY_NAME + TAGLESS_ENVELOPE_TYPE
 
-        override fun invoke(meta: Meta, context: Context): EnvelopeFormat {
-            return TaglessEnvelopeFormat(context.io, meta)
-        }
+        override fun build(context: Context, meta: Meta): EnvelopeFormat = TaglessEnvelopeFormat(context.io, meta)
 
-        private val default by lazy { invoke() }
+        private val default by lazy { build(Global, Meta.EMPTY) }
 
-        override fun readPartial(input: Input): PartialEnvelope =
-            default.run { readPartial(input) }
+        override fun readFrom(binary: Binary): Envelope = default.run { readFrom(binary) }
 
-        override fun writeEnvelope(
-            output: Output,
-            envelope: Envelope,
-            metaFormatFactory: MetaFormatFactory,
-            formatMeta: Meta,
+        override fun writeTo(
+            sink: Sink,
+            obj: Envelope,
         ): Unit = default.run {
-            writeEnvelope(
-                output,
-                envelope,
-                metaFormatFactory,
-                formatMeta
-            )
+            writeTo(sink, obj)
         }
 
-        override fun readObject(input: Input): Envelope = default.readObject(input)
+        override fun readFrom(source: Source): Envelope = default.readFrom(source)
 
         override fun peekFormat(io: IOPlugin, binary: Binary): EnvelopeFormat? {
             return try {
                 binary.read {
-                    val string = readRawString(TAGLESS_ENVELOPE_HEADER.length)
+                    val string = readByteString(TAGLESS_ENVELOPE_HEADER.size)
                     return@read if (string == TAGLESS_ENVELOPE_HEADER) {
                         TaglessEnvelopeFormat(io)
                     } else {

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

@@ -1,51 +1,235 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.charsets.Charsets
-import io.ktor.utils.io.charsets.decodeExactBytes
-import io.ktor.utils.io.core.*
+import kotlinx.io.*
+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
 
-public fun Output.writeRawString(str: String) {
-    writeFully(str.toByteArray(Charsets.ISO_8859_1))
+/**
+ * Convert a string literal, containing only ASCII characters to a [ByteString].
+ * Throws an error if there are non-ASCII characters.
+ */
+public fun String.toAsciiByteString(): ByteString {
+    val bytes = ByteArray(length) {
+        val char = get(it)
+        val code = char.code
+        if (code > Byte.MAX_VALUE) error("Symbol $char is not ASCII symbol") else code.toByte()
+    }
+    return ByteString(bytes)
 }
 
-public fun Output.writeUtf8String(str: String) {
-    writeFully(str.encodeToByteArray())
-}
+public inline fun Buffer(block: Sink.() -> Unit): Buffer = Buffer().apply(block)
 
-@OptIn(ExperimentalIoApi::class)
-public fun Input.readRawString(size: Int): String {
-    return Charsets.ISO_8859_1.newDecoder().decodeExactBytes(this, size)
-}
+//public fun Source.readSafeUtf8Line(): String = readUTF8Line() ?: error("Line not found")
 
-public fun Input.readUtf8String(): String = readBytes().decodeToString()
+public inline fun ByteArray(block: Sink.() -> Unit): ByteArray =
+    Buffer(block).readByteArray()
 
-public fun Input.readSafeUtf8Line(): String = readUTF8Line() ?: error("Line not found")
+public inline fun Binary(block: Sink.() -> Unit): Binary =
+    ByteArray(block).asBinary()
 
-public inline fun buildByteArray(expectedSize: Int = 16, block: Output.() -> Unit): ByteArray {
-    val builder = BytePacketBuilder(expectedSize)
-    builder.block()
-    return builder.build().readBytes()
-}
-
-public inline fun Binary(expectedSize: Int = 16, block: Output.() -> Unit): Binary =
-    buildByteArray(expectedSize, block).asBinary()
+public operator fun Binary.get(range: IntRange): Binary = view(range.first, range.last - range.first)
 
 /**
- * View section of a [Binary] as an independent binary
+ * Return inferred [EnvelopeFormat] if only one format could read given file. If no format accepts the binary, return null. If
+ * multiple formats accept binary, throw an error.
  */
-public class BinaryView(private val source: Binary, private val start: Int, override val size: Int) : Binary {
-
-    init {
-        require(start > 0)
-        require(start + size <= source.size) { "View boundary is outside source binary size" }
+public fun IOPlugin.peekBinaryEnvelopeFormat(binary: Binary): EnvelopeFormat? {
+    val formats = envelopeFormatFactories.mapNotNull { factory ->
+        factory.peekFormat(this@peekBinaryEnvelopeFormat, binary)
     }
 
-    override fun <R> read(offset: Int, atMost: Int, block: Input.() -> R): R {
-        return source.read(start + offset, min(size, atMost), block)
+    return when (formats.size) {
+        0 -> null
+        1 -> formats.first()
+        else -> error("Envelope format binary recognition clash: $formats")
     }
 }
 
-public fun Binary.view(start: Int, size: Int): BinaryView = BinaryView(this, start, size)
+/**
+ * A zero-copy read from
+ */
+@DFExperimental
+public fun IOPlugin.readEnvelope(
+    binary: Binary,
+    readNonEnvelopes: Boolean = false,
+    formatPicker: IOPlugin.(Binary) -> EnvelopeFormat? = IOPlugin::peekBinaryEnvelopeFormat,
+): Envelope = formatPicker(binary)?.readFrom(binary) ?: if (readNonEnvelopes) {
+    // if no format accepts file, read it as binary
+    Envelope(Meta.EMPTY, binary)
+} else error("Can't infer format for $binary")
 
-public operator fun Binary.get(range: IntRange): BinaryView = view(range.first, range.last - range.first)
+@DFExperimental
+public fun IOPlugin.readEnvelope(
+    string: String,
+    readNonEnvelopes: Boolean = false,
+    formatPicker: IOPlugin.(Binary) -> EnvelopeFormat? = IOPlugin::peekBinaryEnvelopeFormat,
+): Envelope = readEnvelope(string.encodeToByteArray().asBinary(), readNonEnvelopes, formatPicker)
+
+
+private class RingByteArray(
+    private val buffer: ByteArray,
+    private var startIndex: Int = 0,
+    var size: Int = 0,
+) {
+    operator fun get(index: Int): Byte {
+        require(index >= 0) { "Index must be positive" }
+        require(index < size) { "Index $index is out of circular buffer size $size" }
+        return buffer[startIndex.forward(index)]
+    }
+
+    fun isFull(): Boolean = size == buffer.size
+
+    fun push(element: Byte) {
+        buffer[startIndex.forward(size)] = element
+        if (isFull()) startIndex++ else size++
+
+    }
+
+    private fun Int.forward(n: Int): Int = (this + n) % (buffer.size)
+
+    fun contentEquals(inputArray: ByteArray): Boolean = when {
+        inputArray.size != buffer.size -> false
+        size < buffer.size -> false
+        else -> inputArray.indices.all { inputArray[it] == get(it) }
+    }
+
+    fun contentEquals(byteString: ByteString): Boolean = when {
+        byteString.size != buffer.size -> false
+        size < buffer.size -> false
+        else -> (0 until byteString.size).all { byteString[it] == get(it) }
+    }
+
+}
+
+private fun RingByteArray.toArray(): ByteArray = ByteArray(size) { get(it) }
+
+/**
+ * Read [Source] into [output] until designated multibyte [separator] and optionally continues until
+ * the end of the line after it. Throw error if [separator] not found and [atMost] bytes are read.
+ * Also fails if [separator] not found until the end of input.
+ *
+ * The Separator itself is not read into [Sink].
+ *
+ * @param errorOnEof if true error is thrown if separator is never encountered
+ *
+ * @return bytes actually being read, including separator
+ */
+public fun Source.readWithSeparatorTo(
+    output: Sink?,
+    separator: ByteString,
+    atMost: Int = Int.MAX_VALUE,
+    errorOnEof: Boolean = false,
+): Int {
+    var counter = 0
+    val rb = RingByteArray(ByteArray(separator.size))
+
+    while (!exhausted()) {
+        val byte = readByte()
+        counter++
+        if (counter >= atMost) error("Maximum number of bytes to be read $atMost reached.")
+        rb.push(byte)
+        if (rb.contentEquals(separator)) {
+            return counter
+        } else if (rb.isFull()) {
+            output?.writeByte(rb[0])
+        }
+    }
+
+    if (errorOnEof) {
+        error("Read to the end of input without encountering ${separator.decodeToString()}")
+    } else {
+        for (i in 1 until rb.size) {
+            output?.writeByte(rb[i])
+        }
+        counter += (rb.size - 1)
+        return counter
+    }
+}
+
+/**
+ * Discard all bytes until [separator] is encountered. Separator is discarded sa well.
+ * Return the total number of bytes read.
+ */
+public fun Source.discardWithSeparator(
+    separator: ByteString,
+    atMost: Int = Int.MAX_VALUE,
+    errorOnEof: Boolean = false,
+): Int = readWithSeparatorTo(null, separator, atMost, errorOnEof)
+
+/**
+ * Discard all symbol until newline is discovered. Carriage return is not discarded.
+ */
+public fun Source.discardLine(
+    atMost: Int = Int.MAX_VALUE,
+    errorOnEof: Boolean = false,
+): Int = discardWithSeparator("\n".encodeToByteString(), atMost, errorOnEof)
+
+
+/**
+ * A [Source] based on [ByteArray]
+ */
+internal class ByteArraySource(
+    private val byteArray: ByteArray,
+    private val offset: Int = 0,
+    private val size: Int = byteArray.size - offset,
+) : RawSource {
+
+    init {
+        require(offset >= 0) { "Offset must be positive" }
+        require(offset + size <= byteArray.size) { "End index is ${offset + size}, but the array size is ${byteArray.size}" }
+    }
+
+    private var pointer = offset
+
+    override fun close() {
+        // Do nothing
+    }
+
+    override fun readAtMostTo(sink: Buffer, byteCount: Long): Long {
+        if (pointer == offset + size) return -1
+        val byteRead = min(byteCount.toInt(), (size + offset - pointer))
+        sink.write(byteArray, pointer, pointer + byteRead)
+        pointer += byteRead
+        return byteRead.toLong()
+    }
+}
+
+/**
+ * A [Source] based on [String]
+ */
+public class StringSource(
+    public val string: String,
+    public val offset: Int = 0,
+    public val size: Int = string.length - offset,
+) : RawSource {
+
+    private var pointer = offset
+
+    override fun close() {
+        // Do nothing
+    }
+
+    override fun readAtMostTo(sink: Buffer, byteCount: Long): Long {
+        if (pointer == offset + size) return -1
+        val byteRead = min(byteCount.toInt(), (size + offset - pointer))
+        sink.writeString(string, pointer, pointer + byteRead)
+        pointer += byteRead
+        return byteRead.toLong()
+    }
+}
+
+public fun Sink.writeDouble(value: Double) {
+    writeLong(value.toBits())
+}
+
+public fun Source.readDouble(): Double = Double.fromBits(readLong())
+
+public fun Sink.writeFloat(value: Float) {
+    writeInt(value.toBits())
+}
+
+public fun Source.readFloat(): Float = Float.fromBits(readInt())

dataforge-io/src/commonTest/kotlin/space/kscience/dataforge/io/BinaryTest.kt

@@ -1,6 +1,5 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.readInt
 import kotlin.test.Test
 import kotlin.test.assertEquals
 

dataforge-io/src/commonTest/kotlin/space/kscience/dataforge/io/EnvelopeFormatTest.kt

@@ -1,7 +1,7 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.readDouble
-import io.ktor.utils.io.core.writeDouble
+import kotlinx.io.readByteArray
+import kotlinx.io.writeString
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -9,42 +9,56 @@ import kotlin.test.assertEquals
 class EnvelopeFormatTest {
     val envelope = Envelope {
         type = "test.format"
-        meta{
+        meta {
             "d" put 22.2
         }
-        data{
-            writeDouble(22.2)
-//            repeat(2000){
-//                writeInt(it)
-//            }
+        data {
+            writeString("12345678")
         }
     }
 
     @Test
-    fun testTaggedFormat(){
-        TaggedEnvelopeFormat.run {
-            val byteArray = writeToByteArray(envelope)
-            //println(byteArray.decodeToString())
-            val res = readFromByteArray(byteArray)
-            assertEquals(envelope.meta,res.meta)
-            val double = res.data?.read {
-                readDouble()
-            }
-            assertEquals(22.2, double)
+    fun testTaggedFormat() = with(TaggedEnvelopeFormat) {
+        val byteArray = writeToByteArray(envelope)
+        val res = readFromByteArray(byteArray)
+        assertEquals(envelope.meta, res.meta)
+        val bytes = res.data?.read {
+            readByteArray()
         }
+        assertEquals("12345678", bytes?.decodeToString())
     }
 
     @Test
-    fun testTaglessFormat(){
-        TaglessEnvelopeFormat.run {
-            val byteArray = writeToByteArray(envelope)
-            //println(byteArray.decodeToString())
-            val res = readFromByteArray(byteArray)
-            assertEquals(envelope.meta,res.meta)
-            val double = res.data?.read {
-                readDouble()
-            }
-            assertEquals(22.2, double)
+    fun testTaglessFormat() = with(TaglessEnvelopeFormat) {
+        val byteArray = writeToByteArray(envelope)
+        println(byteArray.decodeToString())
+        val res = readFromByteArray(byteArray)
+        assertEquals(envelope.meta, res.meta)
+        val bytes = res.data?.read {
+            readByteArray()
         }
+        assertEquals("12345678", bytes?.decodeToString())
+    }
+
+    @Test
+    fun testManualDftl() {
+        val envelopeString = """
+            #~DFTL
+            #~META
+            {
+                "@envelope": {
+                    "type": "test.format"
+                },
+                "d": 22.2
+            }
+            #~DATA
+            12345678
+        """.trimIndent()
+        val res = TaglessEnvelopeFormat.readFromByteArray(envelopeString.encodeToByteArray())
+        assertEquals(envelope.meta, res.meta)
+        val bytes = res.data?.read {
+            readByteArray()
+        }
+        assertEquals("12345678", bytes?.decodeToString())
     }
 }

dataforge-io/src/commonTest/kotlin/space/kscience/dataforge/io/IOTest.kt

@@ -1,17 +1,58 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.ByteReadPacket
-import io.ktor.utils.io.core.readBytes
+import kotlinx.io.buffered
+import kotlinx.io.bytestring.encodeToByteString
+import kotlinx.io.readByteArray
+import kotlinx.io.readLine
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertFails
 
 class IOTest {
     @Test
     fun readBytes() {
         val bytes = ByteArray(8) { it.toByte() }
-        val input = ByteReadPacket(bytes)
-        @Suppress("UNUSED_VARIABLE") val first = input.readBytes(4)
-        val second = input.readBytes(4)
+        val input = ByteArraySource(bytes).buffered()
+        @Suppress("UNUSED_VARIABLE") val first = input.readByteArray(4)
+        val second = input.readByteArray(4)
         assertEquals(4.toByte(), second[0])
     }
+
+    @Test
+    fun readUntilSeparator() {
+        val source = """
+            aaa
+            bbb
+            ---
+            ccc
+            ddd
+        """.trimIndent()
+
+        val binary = source.encodeToByteArray().asBinary()
+
+        binary.read {
+            val array = ByteArray {
+                val read = readWithSeparatorTo(this, "---".encodeToByteString()) + discardLine()
+                assertEquals(12, read)
+            }
+            assertEquals("""
+                aaa
+                bbb
+            """.trimIndent(),array.decodeToString().trim())
+            assertEquals("ccc", readLine()?.trim())
+        }
+
+        assertFails {
+            binary.read {
+                discardWithSeparator("---".encodeToByteString(), atMost = 3 )
+            }
+        }
+
+        assertFails {
+            binary.read{
+                discardWithSeparator("-+-".encodeToByteString(), errorOnEof = true)
+            }
+        }
+
+    }
 }

dataforge-io/src/commonTest/kotlin/space/kscience/dataforge/io/MetaFormatTest.kt

@@ -2,35 +2,19 @@ package space.kscience.dataforge.io
 
 import kotlinx.serialization.json.*
 import space.kscience.dataforge.meta.*
-import space.kscience.dataforge.meta.JsonMeta.Companion.JSON_ARRAY_KEY
-import space.kscience.dataforge.values.ListValue
-import space.kscience.dataforge.values.number
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
-fun Meta.toByteArray(format: MetaFormat = JsonMetaFormat) = buildByteArray {
-    format.writeObject(this@buildByteArray, this@toByteArray)
+
+fun Meta.toByteArray(format: MetaFormat = JsonMetaFormat) = ByteArray {
+    format.writeTo(this@ByteArray, this@toByteArray)
 }
 
 fun MetaFormat.fromByteArray(packet: ByteArray): Meta {
-    return packet.asBinary().read { readObject(this) }
+    return packet.asBinary().read { readFrom(this) }
 }
 
 class MetaFormatTest {
-    @Test
-    fun testBinaryMetaFormat() {
-        val meta = Meta {
-            "a" put 22
-            "node" put {
-                "b" put "DDD"
-                "c" put 11.1
-                "array" put doubleArrayOf(1.0, 2.0, 3.0)
-            }
-        }
-        val bytes = meta.toByteArray(BinaryMetaFormat)
-        val result = BinaryMetaFormat.fromByteArray(bytes)
-        assertEquals(meta, result)
-    }
 
     @Test
     fun testJsonMetaFormat() {
@@ -51,36 +35,36 @@ class MetaFormatTest {
             if (meta[it] != result[it]) error("${meta[it]} != ${result[it]}")
         }
 
-        assertEquals<Meta>(meta, result)
+        assertEquals(meta, result)
     }
 
     @Test
     fun testJsonToMeta() {
         val json = buildJsonArray {
             //top level array
-            add(buildJsonArray {
-                add(JsonPrimitive(88))
-                add(buildJsonObject {
+            addJsonArray {
+                add(88)
+                addJsonObject {
                     put("c", "aasdad")
                     put("d", true)
-                })
-            })
+                }
+            }
             add("value")
-            add(buildJsonArray {
-                add(JsonPrimitive(1.0))
-                add(JsonPrimitive(2.0))
-                add(JsonPrimitive(3.0))
-            })
+            addJsonArray {
+                add(1.0)
+                add(2.0)
+                add(3.0)
+            }
         }
-        val meta = json.toMetaItem().node!!
+        val meta = json.toMeta()
 
-        assertEquals(true, meta["$JSON_ARRAY_KEY[0].$JSON_ARRAY_KEY[1].d"].boolean)
-        assertEquals("value", meta["$JSON_ARRAY_KEY[1]"].string)
-        assertEquals(listOf(1.0, 2.0, 3.0), meta["$JSON_ARRAY_KEY[2"].value?.list?.map { it.number.toDouble() })
+        assertEquals(true, meta["${Meta.JSON_ARRAY_KEY}[0].${Meta.JSON_ARRAY_KEY}[1].d"].boolean)
+        assertEquals("value", meta["${Meta.JSON_ARRAY_KEY}[1]"].string)
+        assertEquals(listOf(1.0, 2.0, 3.0), meta["${Meta.JSON_ARRAY_KEY}[2]"]?.value?.list?.map { it.double })
     }
 
     @Test
-    fun testJsonStringToMeta(){
+    fun testJsonStringToMeta() {
         val jsonString = """
             {
                 "comments": [
@@ -98,8 +82,8 @@ class MetaFormatTest {
             }
         """.trimIndent()
         val json = Json.parseToJsonElement(jsonString)
-        val meta = json.toMetaItem().node!!
-        assertEquals(ListValue.EMPTY, meta["comments"].value)
+        val meta = json.toMeta()
+        assertEquals(ListValue.EMPTY, meta["comments"]?.value)
     }
 
 }

dataforge-io/src/commonTest/kotlin/space/kscience/dataforge/io/MetaSerializerTest.kt

@@ -5,9 +5,8 @@ import kotlinx.serialization.cbor.Cbor
 import kotlinx.serialization.json.Json
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.MetaSerializer
-import space.kscience.dataforge.meta.TypedMetaItem
+import space.kscience.dataforge.meta.seal
 import space.kscience.dataforge.names.Name
-import space.kscience.dataforge.names.toName
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -28,7 +27,7 @@ class MetaSerializerTest {
     fun testMetaSerialization() {
         val string = JSON_PRETTY.encodeToString(MetaSerializer, meta)
         println(string)
-        val restored = JSON_PLAIN.decodeFromString(MetaSerializer, string)
+        val restored = JSON_PLAIN.decodeFromString(MetaSerializer, string).seal()
         assertEquals(meta, restored)
     }
 
@@ -43,7 +42,7 @@ class MetaSerializerTest {
 
     @Test
     fun testNameSerialization() {
-        val name = "a.b.c".toName()
+        val name = Name.parse("a.b.c")
         val string = JSON_PRETTY.encodeToString(Name.serializer(), name)
         val restored = JSON_PLAIN.decodeFromString(Name.serializer(), string)
         assertEquals(name, restored)
@@ -52,7 +51,7 @@ class MetaSerializerTest {
     @OptIn(ExperimentalSerializationApi::class)
     @Test
     fun testMetaItemDescriptor() {
-        val descriptor = TypedMetaItem.serializer(MetaSerializer).descriptor.getElementDescriptor(0)
+        val descriptor = MetaSerializer.descriptor.getElementDescriptor(0)
         println(descriptor)
     }
 }

dataforge-io/src/commonTest/kotlin/space/kscience/dataforge/io/MultipartTest.kt

@@ -1,5 +1,6 @@
 package space.kscience.dataforge.io
 
+import kotlinx.io.writeString
 import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.int
@@ -18,32 +19,31 @@ class MultipartTest {
                 "value" put it
             }
             data {
-                writeUtf8String("Hello World $it")
+                writeString("Hello World $it")
                 repeat(300) {
-                    writeRawString("$it ")
+                    writeString("$it ")
                 }
             }
         }
     }
 
     val partsEnvelope = Envelope {
-        envelopes(envelopes, TaglessEnvelopeFormat)
+        envelopes(envelopes)
     }
 
     @Test
     fun testParts() {
-        TaglessEnvelopeFormat.run {
-            val singleEnvelopeData = toBinary(envelopes[0])
-            val singleEnvelopeSize = singleEnvelopeData.size
-            val bytes = toBinary(partsEnvelope)
-            assertTrue(envelopes.size * singleEnvelopeSize < bytes.size)
-            val reconstructed = bytes.readWith(this)
-            println(reconstructed.meta)
-            val parts = reconstructed.parts()
-            val envelope = parts[2].envelope(io)
-            assertEquals(2, envelope.meta["value"].int)
-            println(reconstructed.data!!.size)
-        }
+        val format = TaggedEnvelopeFormat
+        val singleEnvelopeData = Binary(envelopes[0], format)
+        val singleEnvelopeSize = singleEnvelopeData.size
+        val bytes = Binary(partsEnvelope, format)
+        assertTrue(envelopes.size * singleEnvelopeSize < bytes.size)
+        val reconstructed = bytes.readWith(format)
+        println(reconstructed.meta)
+        val parts = reconstructed.parts()
+        val envelope = parts[2].envelope()
+        assertEquals(2, envelope.meta["value"].int)
+        println(reconstructed.data!!.size)
     }
 
 }

dataforge-io/src/commonTest/kotlin/space/kscience/dataforge/io/ioTestUtils.kt

@@ -1,12 +1,11 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.ByteReadPacket
-import io.ktor.utils.io.core.use
+import kotlinx.io.buffered
 
 
-fun <T : Any> IOFormat<T>.writeToByteArray(obj: T): ByteArray = buildByteArray {
-    writeObject(this, obj)
+fun <T : Any> IOFormat<T>.writeToByteArray(obj: T): ByteArray = ByteArray {
+    writeTo(this, obj)
 }
-fun <T : Any> IOFormat<T>.readFromByteArray(array: ByteArray): T = ByteReadPacket(array).use {
-    readObject(it)
+fun <T : Any> IOFormat<T>.readFromByteArray(array: ByteArray): T = ByteArraySource(array).buffered().use {
+    readFrom(it)
 }

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

@@ -1,15 +1,18 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.*
-import io.ktor.utils.io.streams.asOutput
+
+import kotlinx.coroutines.runBlocking
+import kotlinx.io.Sink
+import kotlinx.io.Source
+import kotlinx.io.asSink
+import kotlinx.io.buffered
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.descriptors.NodeDescriptor
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
 import space.kscience.dataforge.meta.isEmpty
 import space.kscience.dataforge.misc.DFExperimental
 import java.nio.file.Files
 import java.nio.file.Path
 import java.nio.file.StandardOpenOption
-import kotlin.io.path.ExperimentalPathApi
 import kotlin.io.path.inputStream
 import kotlin.math.min
 import kotlin.reflect.full.isSupertypeOf
@@ -23,86 +26,114 @@ internal class PathBinary(
     override val size: Int = Files.size(path).toInt() - fileOffset,
 ) : Binary {
 
-    @OptIn(ExperimentalPathApi::class)
-    override fun <R> read(offset: Int, atMost: Int, block: Input.() -> R): R {
+    override fun <R> read(offset: Int, atMost: Int, block: Source.() -> R): R = runBlocking {
+        readSuspend(offset, atMost, block)
+    }
+
+    override suspend fun <R> readSuspend(offset: Int, atMost: Int, block: suspend Source.() -> R): R {
         val actualOffset = offset + fileOffset
         val actualSize = min(atMost, size - offset)
         val array = path.inputStream().use {
             it.skip(actualOffset.toLong())
             it.readNBytes(actualSize)
         }
-        return ByteReadPacket(array).block()
+        return ByteArraySource(array).buffered().use { it.block() }
     }
+
+    override fun view(offset: Int, binarySize: Int) = PathBinary(path, fileOffset + offset, binarySize)
 }
 
 public fun Path.asBinary(): Binary = PathBinary(this)
 
-public fun <R> Path.read(block: Input.() -> R): R = asBinary().read(block = block)
+public fun <R> Path.read(block: Source.() -> R): R = asBinary().read(block = block)
 
 /**
  * Write a live output to a newly created file. If file does not exist, throws error
  */
-public fun Path.write(block: Output.() -> Unit): Unit {
+public fun Path.write(block: Sink.() -> Unit): Unit {
     val stream = Files.newOutputStream(this, StandardOpenOption.WRITE, StandardOpenOption.CREATE_NEW)
-    stream.asOutput().use(block)
+    stream.asSink().buffered().use(block)
 }
 
 /**
  * Create a new file or append to exiting one with given output [block]
  */
-public fun Path.append(block: Output.() -> Unit): Unit {
+public fun Path.append(block: Sink.() -> Unit): Unit {
     val stream = Files.newOutputStream(
         this,
         StandardOpenOption.WRITE, StandardOpenOption.APPEND, StandardOpenOption.CREATE
     )
-    stream.asOutput().use(block)
+    stream.asSink().buffered().use(block)
 }
 
 /**
  * Create a new file or replace existing one using given output [block]
  */
-public fun Path.rewrite(block: Output.() -> Unit): Unit {
+public fun Path.rewrite(block: Sink.() -> Unit): Unit {
     val stream = Files.newOutputStream(
         this,
         StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.CREATE
     )
-    stream.asOutput().use(block)
+    stream.asSink().buffered().use(block)
 }
 
-public fun Path.readEnvelope(format: EnvelopeFormat): Envelope {
-    val partialEnvelope: PartialEnvelope = asBinary().read {
-        format.run {
-            readPartial(this@read)
-        }
-    }
-    val offset: Int = partialEnvelope.dataOffset.toInt()
-    val size: Int = partialEnvelope.dataSize?.toInt() ?: (Files.size(this).toInt() - offset)
-    val binary = PathBinary(this, offset, size)
-    return SimpleEnvelope(partialEnvelope.meta, binary)
-}
+@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>? {
-    return ioFormatFactories.find { it.type.isSupertypeOf(typeOf<T>()) } as IOFormat<T>?
+public inline fun <reified T : Any> IOPlugin.resolveIOFormat(): IOFormat<T>? =
+    ioFormatFactories.find { it.type.isSupertypeOf(typeOf<T>()) } as IOFormat<T>?
+
+
+public val IOPlugin.Companion.META_FILE_NAME: String get() = "@meta"
+public val IOPlugin.Companion.DATA_FILE_NAME: String get() = "@data"
+
+/**
+ * Read file containing meta using given [formatOverride] or file extension to infer meta type.
+ * If [path] is a directory search for file starting with `meta` in it.
+ *
+ * Returns null if meta could not be resolved
+ */
+public fun IOPlugin.readMetaFileOrNull(
+    path: Path,
+    formatOverride: MetaFormat? = null,
+    descriptor: MetaDescriptor? = null,
+): Meta? {
+    if (!Files.exists(path)) return null
+
+    val actualPath: Path = if (Files.isDirectory(path)) {
+        Files.list(path).asSequence().find { it.fileName.startsWith(IOPlugin.META_FILE_NAME) }
+            ?: return null
+    } else {
+        path
+    }
+    val extension = actualPath.fileName.toString().substringAfterLast('.')
+
+    val metaFormat = formatOverride ?: resolveMetaFormat(extension) ?: return null
+    return actualPath.read {
+        metaFormat.readMeta(this, descriptor)
+    }
 }
 
 /**
  * Read file containing meta using given [formatOverride] or file extension to infer meta type.
- * If [path] is a directory search for file starting with `meta` in it
+ * If [path] is a directory search for file starting with `meta` in it.
+ *
+ * Fails if nothing works.
  */
 public fun IOPlugin.readMetaFile(
     path: Path,
     formatOverride: MetaFormat? = null,
-    descriptor: NodeDescriptor? = null,
+    descriptor: MetaDescriptor? = null,
 ): Meta {
     if (!Files.exists(path)) error("Meta file $path does not exist")
 
     val actualPath: Path = if (Files.isDirectory(path)) {
-        Files.list(path).asSequence().find { it.fileName.startsWith("meta") }
+        Files.list(path).asSequence().find { it.fileName.startsWith(IOPlugin.META_FILE_NAME) }
             ?: error("The directory $path does not contain meta file")
     } else {
         path
@@ -110,13 +141,12 @@ public fun IOPlugin.readMetaFile(
     val extension = actualPath.fileName.toString().substringAfterLast('.')
 
     val metaFormat = formatOverride ?: resolveMetaFormat(extension) ?: error("Can't resolve meta format $extension")
-    return metaFormat.run {
-        actualPath.read {
-            readMeta(this, descriptor)
-        }
+    return actualPath.read {
+        metaFormat.readMeta(this, descriptor)
     }
 }
 
+
 /**
  * Write meta to file using [metaFormat]. If [path] is a directory, write a file with name equals name of [metaFormat].
  * Like "meta.json"
@@ -125,7 +155,7 @@ public fun IOPlugin.writeMetaFile(
     path: Path,
     meta: Meta,
     metaFormat: MetaFormatFactory = JsonMetaFormat,
-    descriptor: NodeDescriptor? = null,
+    descriptor: MetaDescriptor? = null,
 ) {
     val actualPath = if (Files.isDirectory(path)) {
         path.resolve("@" + metaFormat.name.toString())
@@ -145,19 +175,9 @@ public fun IOPlugin.writeMetaFile(
  */
 public fun IOPlugin.peekFileEnvelopeFormat(path: Path): EnvelopeFormat? {
     val binary = path.asBinary()
-    val formats = envelopeFormatFactories.mapNotNull { factory ->
-        factory.peekFormat(this@peekFileEnvelopeFormat, binary)
-    }
-
-    return when (formats.size) {
-        0 -> null
-        1 -> formats.first()
-        else -> error("Envelope format binary recognition clash: $formats")
-    }
+    return peekBinaryEnvelopeFormat(binary)
 }
 
-public val IOPlugin.Companion.META_FILE_NAME: String get() = "@meta"
-public val IOPlugin.Companion.DATA_FILE_NAME: String get() = "@data"
 
 /**
  * Read and envelope from file if the file exists, return null if file does not exist.
@@ -203,22 +223,11 @@ public fun IOPlugin.readEnvelopeFile(
         return SimpleEnvelope(meta, data)
     }
 
-    return formatPicker(path)?.let { format ->
-        path.readEnvelope(format)
-    } ?: if (readNonEnvelopes) { // if no format accepts file, read it as binary
+    return formatPicker(path)?.readFile(path) ?: if (readNonEnvelopes) { // if no format accepts file, read it as binary
         SimpleEnvelope(Meta.EMPTY, path.asBinary())
     } else error("Can't infer format for file $path")
 }
 
-/**
- * Write a binary into file. Throws an error if file already exists
- */
-public fun <T : Any> IOFormat<T>.writeToFile(path: Path, obj: T) {
-    path.write {
-        writeObject(this, obj)
-    }
-}
-
 /**
  * Write envelope file to given [path] using [envelopeFormat] and optional [metaFormat]
  */
@@ -227,10 +236,9 @@ public fun IOPlugin.writeEnvelopeFile(
     path: Path,
     envelope: Envelope,
     envelopeFormat: EnvelopeFormat = TaggedEnvelopeFormat,
-    metaFormat: MetaFormatFactory? = null,
 ) {
     path.rewrite {
-        envelopeFormat.writeEnvelope(this, envelope, metaFormat ?: envelopeFormat.defaultMetaFormat)
+        envelopeFormat.writeTo(this, envelope)
     }
 }
 
@@ -255,7 +263,7 @@ public fun IOPlugin.writeEnvelopeDirectory(
     val dataFile = path.resolve(IOPlugin.DATA_FILE_NAME)
     dataFile.write {
         envelope.data?.read {
-            val copied = copyTo(this@write)
+            val copied = transferTo(this@write)
             if (copied != envelope.data?.size?.toLong()) {
                 error("The number of copied bytes does not equal data size")
             }

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

@@ -0,0 +1,11 @@
+package space.kscience.dataforge.io
+
+import kotlinx.io.Source
+import kotlinx.io.asSource
+import kotlinx.io.buffered
+
+
+public fun IOPlugin.resource(name: String): Binary? = { }.javaClass.getResource(name)?.readBytes()?.asBinary()
+
+public inline fun <R> IOPlugin.readResource(name: String, block: Source.() -> R): R =
+    {  }.javaClass.getResource(name)?.openStream()?.asSource()?.buffered()?.block() ?: error("Can't read resource $name")

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

@@ -0,0 +1,27 @@
+package space.kscience.dataforge.io
+
+import space.kscience.dataforge.context.ContextBuilder
+import space.kscience.dataforge.meta.set
+import space.kscience.dataforge.meta.string
+import java.nio.file.Path
+import kotlin.io.path.Path
+
+
+public val IOPlugin.workDirectory: Path
+    get() {
+        val workDirectoryPath = meta[IOPlugin.WORK_DIRECTORY_KEY].string
+            ?: context.properties[IOPlugin.WORK_DIRECTORY_KEY].string
+            ?: ".dataforge"
+
+        return Path(workDirectoryPath)
+    }
+
+public fun ContextBuilder.workDirectory(path: String) {
+    properties {
+        set(IOPlugin.WORK_DIRECTORY_KEY, path)
+    }
+}
+
+public fun ContextBuilder.workDirectory(path: Path) {
+    workDirectory(path.toAbsolutePath().toString())
+}

dataforge-io/src/jvmTest/kotlin/space/kscience/dataforge/io/FileBinaryTest.kt

@@ -1,6 +1,5 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.writeDouble
 import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.misc.DFExperimental
 import java.nio.file.Files

dataforge-io/src/jvmTest/kotlin/space/kscience/dataforge/io/FileEnvelopeTest.kt

@@ -1,6 +1,5 @@
 package space.kscience.dataforge.io
 
-import io.ktor.utils.io.core.writeDouble
 import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.misc.DFExperimental
 import java.nio.file.Files

dataforge-meta/README.md

@@ -0,0 +1,23 @@
+# Module dataforge-meta
+
+Meta definition and basic operations on meta
+
+## Usage
+
+## Artifact:
+
+The Maven coordinates of this project are `space.kscience:dataforge-meta:0.7.0`.
+
+**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")
+}
+```