From f67fb63c451d97aed46bd39009bc985a8e0b69f0 Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Mon, 13 Apr 2020 15:23:05 +0300
Subject: [PATCH 1/8] Fix for #48

---
 build.gradle.kts                              |  2 +-
 .../hep/dataforge/io/tcp/EnvelopeServer.kt    |  2 +-
 .../kotlin/hep/dataforge/meta/JsonMeta.kt     |  4 +-
 .../kotlin/hep/dataforge/meta/Meta.kt         |  8 +-
 .../hep/dataforge/meta/MutableMetaDelegate.kt |  4 +
 .../meta/descriptors/ItemDescriptor.kt        | 82 +++++++++----------
 .../meta/descriptors/DescriptorTest.kt        | 11 ++-
 .../hep/dataforge/workspace/TaskBuilder.kt    |  6 +-
 8 files changed, 65 insertions(+), 54 deletions(-)

diff --git a/build.gradle.kts b/build.gradle.kts
index d73b0e60..43ea9882 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,7 +6,7 @@ plugins {
     id("scientifik.publish") version toolsVersion apply false
 }
 
-val dataforgeVersion by extra("0.1.7")
+val dataforgeVersion by extra("0.1.8-dev-1")
 
 val bintrayRepo by extra("dataforge")
 val githubProject by extra("dataforge-core")
diff --git a/dataforge-io/src/jvmMain/kotlin/hep/dataforge/io/tcp/EnvelopeServer.kt b/dataforge-io/src/jvmMain/kotlin/hep/dataforge/io/tcp/EnvelopeServer.kt
index fc61ee49..b9569279 100644
--- a/dataforge-io/src/jvmMain/kotlin/hep/dataforge/io/tcp/EnvelopeServer.kt
+++ b/dataforge-io/src/jvmMain/kotlin/hep/dataforge/io/tcp/EnvelopeServer.kt
@@ -28,7 +28,7 @@ class EnvelopeServer(
     fun start() {
         if (job == null) {
             logger.info { "Starting envelope server on port $port" }
-            val job = scope.launch(Dispatchers.IO) {
+            job = scope.launch(Dispatchers.IO) {
                 val serverSocket = ServerSocket(port)
                 //TODO add handshake and format negotiation
                 while (isActive && !serverSocket.isClosed) {
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/JsonMeta.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/JsonMeta.kt
index 89ab1b3e..48ef6c4e 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/JsonMeta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/JsonMeta.kt
@@ -28,7 +28,7 @@ fun Value.toJson(descriptor: ValueDescriptor? = null): JsonElement {
 }
 
 //Use these methods to customize JSON key mapping
-private fun String.toJsonKey(descriptor: ItemDescriptor?) = descriptor?.getProperty("jsonName").string ?: toString()
+private fun String.toJsonKey(descriptor: ItemDescriptor?) = descriptor?.attributes["jsonName"].string ?: toString()
 
 //private fun NodeDescriptor?.getDescriptor(key: String) = this?.items?.get(key)
 
@@ -146,7 +146,7 @@ class JsonMeta(val json: JsonObject, val descriptor: NodeDescriptor? = null) : M
     @Suppress("UNCHECKED_CAST")
     private operator fun MutableMap<String, MetaItem<JsonMeta>>.set(key: String, value: JsonElement): Unit {
         val itemDescriptor = descriptor?.items?.get(key)
-        return when (value) {
+        when (value) {
             is JsonPrimitive -> {
                 this[key] =
                     MetaItem.ValueItem(value.toValue(itemDescriptor as? ValueDescriptor)) as MetaItem<JsonMeta>
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
index 9650b04e..3aa5b848 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
@@ -170,8 +170,12 @@ interface MetaNode<out M : MetaNode<M>> : Meta {
 /**
  * The same as [Meta.get], but with specific node type
  */
-@Suppress("UNCHECKED_CAST")
-operator fun <M : MetaNode<M>> M?.get(name: Name): MetaItem<M>? = (this as Meta)[name] as MetaItem<M>?
+operator fun <M : MetaNode<M>> M?.get(name: Name): MetaItem<M>? = if( this == null) {
+    null
+} else {
+    @Suppress("UNCHECKED_CAST")
+    (this as Meta).get(name) as MetaItem<M>?
+}
 
 operator fun <M : MetaNode<M>> M?.get(key: String): MetaItem<M>? = this[key.toName()]
 
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt
index 0cffb3a3..39a022f4 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt
@@ -99,6 +99,10 @@ fun <M : MutableMeta<M>> M.boolean(default: Boolean, key: Name? = null) =
 fun <M : MutableMeta<M>> M.number(default: Number, key: Name? = null) =
     item(default, key).transform { it.number!! }
 
+@JvmName("lazyValue")
+fun <M : MutableMeta<M>> M.string(key: Name? = null, default: () -> Value) =
+    lazyItem(key, default).transform { it.value!! }
+
 @JvmName("lazyString")
 fun <M : MutableMeta<M>> M.string(key: Name? = null, default: () -> String) =
     lazyItem(key, default).transform { it.string!! }
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
index e025cbb1..02af4374 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
@@ -8,28 +8,28 @@ import hep.dataforge.values.Value
 import hep.dataforge.values.ValueType
 
 @DFBuilder
-sealed class ItemDescriptor : Scheme() {
+sealed class ItemDescriptor(val config: Config) {
 
     /**
      * True if same name siblings with this name are allowed
      *
      * @return
      */
-    var multiple: Boolean by boolean(false)
+    var multiple: Boolean by config.boolean(false)
 
     /**
      * The item description
      *
      * @return
      */
-    var info: String? by string()
+    var info: String? by config.string()
 
     /**
      * Additional attributes of an item. For example validation and widget parameters
      *
      * @return
      */
-    var attributes by config()
+    var attributes by config.node()
 
     /**
      * True if the item is required
@@ -43,7 +43,7 @@ sealed class ItemDescriptor : Scheme() {
  * Configure attributes of the descriptor
  */
 fun ItemDescriptor.attributes(block: Config.() -> Unit) {
-    (attributes ?: Config().also { this.config = it }).apply(block)
+    (attributes ?: Config().also { this.attributes = it }).apply(block)
 }
 
 /**
@@ -65,28 +65,32 @@ fun ItemDescriptor.validateItem(item: MetaItem<*>?): Boolean {
  * @author Alexander Nozik
  */
 @DFBuilder
-class NodeDescriptor private constructor() : ItemDescriptor() {
+class NodeDescriptor(config: Config = Config()) : ItemDescriptor(config) {
+    init {
+        config[IS_NODE_KEY] = true
+    }
+
     /**
      * True if the node is required
      *
      * @return
      */
-    override var required: Boolean by boolean { default == null }
+    override var required: Boolean by config.boolean { default == null }
 
     /**
      * The default for this node. Null if there is no default.
      *
      * @return
      */
-    var default by node()
+    var default by config.node()
 
     val items: Map<String, ItemDescriptor>
         get() = config.getIndexed(ITEM_KEY).mapValues { (_, item) ->
             val node = item.node ?: error("Node descriptor must be a node")
             if (node[IS_NODE_KEY].boolean == true) {
-                NodeDescriptor.wrap(node)
+                NodeDescriptor(node)
             } else {
-                ValueDescriptor.wrap(node)
+                ValueDescriptor(node)
             }
         }
 
@@ -99,7 +103,7 @@ class NodeDescriptor private constructor() : ItemDescriptor() {
             it.value.node[IS_NODE_KEY].boolean == true
         }.associate { (name, item) ->
             val node = item.node ?: error("Node descriptor must be a node")
-            name to NodeDescriptor.wrap(node)
+            name to NodeDescriptor(node)
         }
 
     /**
@@ -110,7 +114,7 @@ class NodeDescriptor private constructor() : ItemDescriptor() {
             it.value.node[IS_NODE_KEY].boolean != true
         }.associate { (name, item) ->
             val node = item.node ?: error("Node descriptor must be a node")
-            name to ValueDescriptor.wrap(node)
+            name to ValueDescriptor(node)
         }
 
     private fun buildNode(name: Name): NodeDescriptor {
@@ -122,7 +126,7 @@ class NodeDescriptor private constructor() : ItemDescriptor() {
                     it[IS_NODE_KEY] = true
                     config[token] = it
                 }
-                wrap(config)
+                NodeDescriptor(config)
             }
             else -> buildNode(name.first()?.asName()!!).buildNode(name.cutFirst())
         }
@@ -137,41 +141,37 @@ class NodeDescriptor private constructor() : ItemDescriptor() {
         config[token] = descriptor.config
     }
 
-    fun defineItem(name: Name, descriptor: ItemDescriptor) {
+    fun item(name: Name, descriptor: ItemDescriptor) {
         buildNode(name.cutLast()).newItem(name.last().toString(), descriptor)
     }
 
-    fun defineItem(name: String, descriptor: ItemDescriptor) {
-        defineItem(name.toName(), descriptor)
+    fun item(name: String, descriptor: ItemDescriptor) {
+        item(name.toName(), descriptor)
     }
 
-    fun defineNode(name: Name, block: NodeDescriptor.() -> Unit) {
-        defineItem(name, NodeDescriptor(block))
+    fun node(name: Name, block: NodeDescriptor.() -> Unit) {
+        item(name, NodeDescriptor().apply(block))
     }
 
-    fun defineNode(name: String, block: NodeDescriptor.() -> Unit) {
-        defineNode(name.toName(), block)
+    fun node(name: String, block: NodeDescriptor.() -> Unit) {
+        node(name.toName(), block)
     }
 
-    fun defineValue(name: Name, block: ValueDescriptor.() -> Unit) {
+    fun value(name: Name, block: ValueDescriptor.() -> Unit) {
         require(name.length >= 1) { "Name length for value descriptor must be non-empty" }
-        defineItem(name, ValueDescriptor(block))
+        item(name, ValueDescriptor().apply(block))
     }
 
-    fun defineValue(name: String, block: ValueDescriptor.() -> Unit) {
-        defineValue(name.toName(), block)
+    fun value(name: String, block: ValueDescriptor.() -> Unit) {
+        value(name.toName(), block)
     }
 
-    companion object : SchemeSpec<NodeDescriptor>(::NodeDescriptor) {
+    companion object{
 
         val ITEM_KEY = "item".asName()
         val IS_NODE_KEY = "@isNode".asName()
 
-        override fun empty(): NodeDescriptor {
-            return super.empty().apply {
-                config[IS_NODE_KEY] = true
-            }
-        }
+        inline operator fun invoke(block: NodeDescriptor.()->Unit) = NodeDescriptor().apply(block)
 
         //TODO infer descriptor from spec
     }
@@ -188,6 +188,8 @@ operator fun ItemDescriptor.get(name: Name): ItemDescriptor? {
     }
 }
 
+operator fun ItemDescriptor.get(name: String): ItemDescriptor? = get(name.toName())
+
 /**
  * A descriptor for meta value
  *
@@ -196,21 +198,21 @@ operator fun ItemDescriptor.get(name: Name): ItemDescriptor? {
  * @author Alexander Nozik
  */
 @DFBuilder
-class ValueDescriptor : ItemDescriptor() {
+class ValueDescriptor(config: Config = Config()) : ItemDescriptor(config) {
 
     /**
      * True if the value is required
      *
      * @return
      */
-    override var required: Boolean by boolean { default == null }
+    override var required: Boolean by config.boolean { default == null }
 
     /**
      * The default for this value. Null if there is no default.
      *
      * @return
      */
-    var default: Value? by value()
+    var default: Value? by config.value()
 
     fun default(v: Any) {
         this.default = Value.of(v)
@@ -221,7 +223,7 @@ class ValueDescriptor : ItemDescriptor() {
      *
      * @return
      */
-    var type: List<ValueType> by item {
+    var type: List<ValueType> by config.item().transform {
         it?.value?.list?.map { v -> ValueType.valueOf(v.string) } ?: emptyList()
     }
 
@@ -248,11 +250,11 @@ class ValueDescriptor : ItemDescriptor() {
      *
      * @return
      */
-    var allowedValues: List<Value> by value {
-        it?.list ?: if (type.size == 1 && type[0] === ValueType.BOOLEAN) {
-            listOf(True, False)
-        } else {
-            emptyList()
+    var allowedValues: List<Value> by config.value().transform {
+        when{
+            it?.list != null -> it.list
+            type.size == 1 && type[0] === ValueType.BOOLEAN ->    listOf(True, False)
+            else -> emptyList()
         }
     }
 
@@ -262,6 +264,4 @@ class ValueDescriptor : ItemDescriptor() {
     fun allow(vararg v: Any) {
         this.allowedValues = v.map { Value.of(it) }
     }
-
-    companion object : SchemeSpec<ValueDescriptor>(::ValueDescriptor)
 }
\ No newline at end of file
diff --git a/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt b/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt
index 77e670c8..9c022637 100644
--- a/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt
+++ b/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt
@@ -3,18 +3,19 @@ package hep.dataforge.meta.descriptors
 import hep.dataforge.values.ValueType
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
 
 class DescriptorTest {
 
     val descriptor = NodeDescriptor {
-        defineNode("aNode") {
+        node("aNode") {
             info = "A root demo node"
-            defineValue("b") {
+            value("b") {
                 info = "b number value"
                 type(ValueType.NUMBER)
             }
-            defineNode("otherNode") {
-                defineValue("otherValue") {
+            node("otherNode") {
+                value("otherValue") {
                     type(ValueType.BOOLEAN)
                     default(false)
                     info = "default value"
@@ -25,6 +26,8 @@ class DescriptorTest {
 
     @Test
     fun testAllowedValues() {
+        val child = descriptor["aNode.b"]
+        assertNotNull(child)
         val allowed = descriptor.nodes["aNode"]?.values?.get("b")?.allowedValues
         assertEquals(emptyList(), allowed)
     }
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
index 7f359914..9ce9cf27 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
@@ -2,9 +2,9 @@ package hep.dataforge.workspace
 
 import hep.dataforge.context.Context
 import hep.dataforge.data.*
-import hep.dataforge.meta.descriptors.NodeDescriptor
 import hep.dataforge.meta.DFBuilder
 import hep.dataforge.meta.Meta
+import hep.dataforge.meta.descriptors.NodeDescriptor
 import hep.dataforge.meta.get
 import hep.dataforge.meta.string
 import hep.dataforge.names.Name
@@ -200,7 +200,7 @@ class TaskBuilder<R : Any>(val name: Name, val type: KClass<out R>) {
      * Use DSL to create a descriptor for this task
      */
     fun description(transform: NodeDescriptor.() -> Unit) {
-        this.descriptor = NodeDescriptor(transform)
+        this.descriptor = NodeDescriptor().apply(transform)
     }
 
     internal fun build(): GenericTask<R> {
@@ -212,7 +212,7 @@ class TaskBuilder<R : Any>(val name: Name, val type: KClass<out R>) {
         return GenericTask(
             name,
             type,
-            descriptor ?: NodeDescriptor.empty(),
+            descriptor ?: NodeDescriptor(),
             modelTransform
         ) {
             val workspace = this

From 0434360d46b2e76f8409c24df97dbcf5b34da196 Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Mon, 13 Apr 2020 15:34:26 +0300
Subject: [PATCH 2/8] Cleanup type variance in Task builder

---
 .../kotlin/hep/dataforge/data/MapAction.kt       |  2 +-
 .../kotlin/hep/dataforge/data/ReduceAction.kt    |  2 +-
 .../kotlin/hep/dataforge/data/SplitAction.kt     |  2 +-
 .../hep/dataforge/workspace/TaskBuilder.kt       | 16 +++++++++++-----
 4 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/MapAction.kt b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/MapAction.kt
index 89e887db..61598349 100644
--- a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/MapAction.kt
+++ b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/MapAction.kt
@@ -31,7 +31,7 @@ class MapActionBuilder<T, R>(var name: Name, var meta: MetaBuilder, val actionMe
 
 
 class MapAction<T : Any, out R : Any>(
-    val inputType: KClass<out T>,
+    val inputType: KClass<T>,
     val outputType: KClass<out R>,
     private val block: MapActionBuilder<T, R>.() -> Unit
 ) : Action<T, R> {
diff --git a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/ReduceAction.kt b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/ReduceAction.kt
index 9bb49151..0efb5506 100644
--- a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/ReduceAction.kt
+++ b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/ReduceAction.kt
@@ -72,7 +72,7 @@ class ReduceGroupBuilder<T : Any, R : Any>(val actionMeta: Meta) {
  * The same rules as for KPipe
  */
 class ReduceAction<T : Any, R : Any>(
-    val inputType: KClass<out T>,
+    val inputType: KClass<T>,
     val outputType: KClass<out R>,
     private val action: ReduceGroupBuilder<T, R>.() -> Unit
 ) : Action<T, R> {
diff --git a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt
index a4f82931..dc29394c 100644
--- a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt
+++ b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt
@@ -33,7 +33,7 @@ class SplitBuilder<T : Any, R : Any>(val name: Name, val meta: Meta) {
 }
 
 class SplitAction<T : Any, R : Any>(
-    val inputType: KClass<out T>,
+    val inputType: KClass<T>,
     val outputType: KClass<out R>,
     private val action: SplitBuilder<T, R>.() -> Unit
 ) : Action<T, R> {
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
index 9ce9cf27..502c669d 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
@@ -16,7 +16,8 @@ import kotlin.reflect.KClass
 @DFBuilder
 class TaskBuilder<R : Any>(val name: Name, val type: KClass<out R>) {
     private var modelTransform: TaskModelBuilder.(Meta) -> Unit = { allData() }
-//    private val additionalDependencies = HashSet<Dependency>()
+
+    //    private val additionalDependencies = HashSet<Dependency>()
     var descriptor: NodeDescriptor? = null
     private val dataTransforms: MutableList<DataTransformation> = ArrayList()
 
@@ -96,7 +97,7 @@ class TaskBuilder<R : Any>(val name: Name, val type: KClass<out R>) {
     }
 
     class TaskEnv(val name: Name, val meta: Meta, val context: Context, val data: DataNode<Any>) {
-        operator fun <T : Any> DirectTaskDependency<T>.invoke(): DataNode<T> = if(placement.isEmpty()){
+        operator fun <T : Any> DirectTaskDependency<T>.invoke(): DataNode<T> = if (placement.isEmpty()) {
             data.cast(task.type)
         } else {
             data[placement].node?.cast(task.type)
@@ -113,10 +114,13 @@ class TaskBuilder<R : Any>(val name: Name, val type: KClass<out R>) {
         crossinline block: MapActionBuilder<T, R>.(TaskEnv) -> Unit
     ) {
         action(from, to) {
+            val env = this
             MapAction(
                 inputType = T::class,
                 outputType = type
-            ) { block(this@action) }
+            ) {
+                block(env)
+            }
         }
     }
 
@@ -150,10 +154,11 @@ class TaskBuilder<R : Any>(val name: Name, val type: KClass<out R>) {
         crossinline block: ReduceGroupBuilder<T, R>.(TaskEnv) -> Unit        //TODO needs KEEP-176
     ) {
         action(from, to) {
+            val env = this
             ReduceAction(
                 inputType = T::class,
                 outputType = type
-            ) { block(this@action) }
+            ) { block(env) }
         }
     }
 
@@ -189,10 +194,11 @@ class TaskBuilder<R : Any>(val name: Name, val type: KClass<out R>) {
         crossinline block: SplitBuilder<T, R>.(TaskEnv) -> Unit  //TODO needs KEEP-176
     ) {
         action(from, to) {
+            val env = this
             SplitAction(
                 inputType = T::class,
                 outputType = type
-            ) { block(this@action) }
+            ) { block(env) }
         }
     }
 

From 7c68fc6e853966d659525f2f7800f429fe96bb6d Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Mon, 13 Apr 2020 16:10:46 +0300
Subject: [PATCH 3/8] add test to descriptor default

---
 .../hep/dataforge/meta/descriptors/DescriptorMeta.kt      | 5 ++++-
 .../hep/dataforge/meta/descriptors/DescriptorTest.kt      | 8 ++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/DescriptorMeta.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/DescriptorMeta.kt
index c0b27925..47c90370 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/DescriptorMeta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/DescriptorMeta.kt
@@ -1,5 +1,6 @@
 package hep.dataforge.meta.descriptors
 
+import hep.dataforge.meta.Laminate
 import hep.dataforge.meta.MetaBase
 import hep.dataforge.meta.MetaItem
 import hep.dataforge.names.NameToken
@@ -15,8 +16,10 @@ class DescriptorMeta(val descriptor: NodeDescriptor) : MetaBase() {
         }
 }
 
+fun NodeDescriptor.buildDefaultMeta() = Laminate(default, DescriptorMeta(this))
+
 fun NodeDescriptor.defaultItem(): MetaItem.NodeItem<*> =
-    MetaItem.NodeItem(default ?: DescriptorMeta(this))
+    MetaItem.NodeItem(buildDefaultMeta())
 
 fun ValueDescriptor.defaultItem(): MetaItem.ValueItem = MetaItem.ValueItem(default ?: Null)
 
diff --git a/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt b/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt
index 9c022637..605cbebd 100644
--- a/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt
+++ b/dataforge-meta/src/commonTest/kotlin/hep/dataforge/meta/descriptors/DescriptorTest.kt
@@ -1,5 +1,7 @@
 package hep.dataforge.meta.descriptors
 
+import hep.dataforge.meta.boolean
+import hep.dataforge.meta.get
 import hep.dataforge.values.ValueType
 import kotlin.test.Test
 import kotlin.test.assertEquals
@@ -31,4 +33,10 @@ class DescriptorTest {
         val allowed = descriptor.nodes["aNode"]?.values?.get("b")?.allowedValues
         assertEquals(emptyList(), allowed)
     }
+
+    @Test
+    fun testDefaultMetaNode(){
+        val meta = descriptor.buildDefaultMeta()
+        assertEquals(false, meta["aNode.otherNode.otherValue"].boolean)
+    }
 }
\ No newline at end of file

From fb28c854b3b4bcffd4c9b6cc34fbf4d43b4ead4c Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Fri, 17 Apr 2020 18:31:22 +0300
Subject: [PATCH 4/8] Fix structured concurrency in Context

---
 .../commonMain/kotlin/hep/dataforge/context/Context.kt    | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt b/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt
index b3adcbfd..3db334c2 100644
--- a/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt
+++ b/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt
@@ -8,10 +8,11 @@ import hep.dataforge.provider.Provider
 import hep.dataforge.provider.top
 import hep.dataforge.values.Value
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
 import mu.KLogger
 import mu.KotlinLogging
 import kotlin.coroutines.CoroutineContext
-import kotlin.coroutines.EmptyCoroutineContext
 import kotlin.jvm.JvmName
 
 /**
@@ -91,8 +92,9 @@ open class Context(
         config.action()
     }
 
-    override val coroutineContext: CoroutineContext
-        get() = EmptyCoroutineContext
+    override val coroutineContext: CoroutineContext = (parent ?: Global).coroutineContext.let { parenContext ->
+        parenContext + SupervisorJob(parenContext[Job])
+    }
 
     /**
      * Detach all plugins and terminate context

From aa52c45c5a33beaf46ad5e22b60cb9978643b3fc Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Sun, 19 Apr 2020 23:13:00 +0300
Subject: [PATCH 5/8] Fix boolean value toString()

---
 .../src/commonMain/kotlin/hep/dataforge/values/Value.kt         | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/values/Value.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/values/Value.kt
index 28a5838c..05c082e9 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/values/Value.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/values/Value.kt
@@ -125,7 +125,7 @@ object False : Value {
     override val number: Number get() = -1.0
     override val string: String get() = "false"
 
-    override fun toString(): String = True.value.toString()
+    override fun toString(): String = value.toString()
 
     override fun equals(other: Any?): Boolean = other === False
     override fun hashCode(): Int = -1

From 5e8e3014f7e4c3614180635338ac8bb373630126 Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Tue, 21 Apr 2020 19:32:29 +0300
Subject: [PATCH 6/8] Node editor for MutableMeta

---
 build.gradle.kts                              |  2 +-
 .../kotlin/hep/dataforge/meta/Configurable.kt |  1 +
 .../kotlin/hep/dataforge/meta/Meta.kt         |  4 +--
 .../kotlin/hep/dataforge/meta/MutableMeta.kt  | 23 +++++++++----
 .../meta/descriptors/ItemDescriptor.kt        | 33 ++++++++++++-------
 5 files changed, 43 insertions(+), 20 deletions(-)

diff --git a/build.gradle.kts b/build.gradle.kts
index 43ea9882..3395cacc 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,7 +6,7 @@ plugins {
     id("scientifik.publish") version toolsVersion apply false
 }
 
-val dataforgeVersion by extra("0.1.8-dev-1")
+val dataforgeVersion by extra("0.1.8-dev-2")
 
 val bintrayRepo by extra("dataforge")
 val githubProject by extra("dataforge-core")
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt
index b38b7d95..884c1c26 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt
@@ -64,4 +64,5 @@ fun Configurable.setProperty(key: String, meta: Meta?) = setProperty(key, meta?.
 
 fun <T : Configurable> T.configure(meta: Meta): T = this.apply { config.update(meta) }
 
+@DFBuilder
 inline fun <T : Configurable> T.configure(action: Config.() -> Unit): T = apply { config.apply(action) }
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
index 3aa5b848..768ddbfa 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
@@ -173,8 +173,8 @@ interface MetaNode<out M : MetaNode<M>> : Meta {
 operator fun <M : MetaNode<M>> M?.get(name: Name): MetaItem<M>? = if( this == null) {
     null
 } else {
-    @Suppress("UNCHECKED_CAST")
-    (this as Meta).get(name) as MetaItem<M>?
+    @Suppress("UNCHECKED_CAST", "ReplaceGetOrSet")
+    (this as Meta).get(name) as MetaItem<M>? // Do not change
 }
 
 operator fun <M : MetaNode<M>> M?.get(key: String): MetaItem<M>? = this[key.toName()]
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt
index bb280734..16fcf40d 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt
@@ -76,11 +76,9 @@ inline fun MutableMeta<*>.remove(name: Name) = set(name, null)
 @Suppress("NOTHING_TO_INLINE")
 inline fun MutableMeta<*>.remove(name: String) = remove(name.toName())
 
-fun MutableMeta<*>.setValue(name: Name, value: Value) =
-    set(name, MetaItem.ValueItem(value))
+fun MutableMeta<*>.setValue(name: Name, value: Value) = set(name, MetaItem.ValueItem(value))
 
-fun MutableMeta<*>.setValue(name: String, value: Value) =
-    set(name.toName(), MetaItem.ValueItem(value))
+fun MutableMeta<*>.setValue(name: String, value: Value) = set(name.toName(), value)
 
 fun MutableMeta<*>.setItem(name: Name, item: MetaItem<*>?) {
     when (item) {
@@ -98,7 +96,7 @@ fun MutableMeta<*>.setNode(name: Name, node: Meta) =
 fun MutableMeta<*>.setNode(name: String, node: Meta) = setNode(name.toName(), node)
 
 /**
- * Universal set method
+ * Universal unsafe set method
  */
 operator fun MutableMeta<*>.set(name: Name, value: Any?) {
     when (value) {
@@ -173,4 +171,17 @@ fun <M : MutableMeta<M>> M.append(name: Name, value: Any?) {
     }
 }
 
-fun <M : MutableMeta<M>> M.append(name: String, value: Any?) = append(name.toName(), value)
\ No newline at end of file
+fun <M : MutableMeta<M>> M.append(name: String, value: Any?) = append(name.toName(), value)
+
+/**
+ * Apply existing node with given [builder] or create a new element with it.
+ */
+@DFExperimental
+fun <M : AbstractMutableMeta<M>> M.edit(name: Name, builder: M.() -> Unit) {
+    val item = when(val existingItem = get(name)){
+        null -> empty().also { set(name, it) }
+        is MetaItem.NodeItem<M> -> existingItem.node
+        else -> error("Can't edit value meta item")
+    }
+    item.apply(builder)
+}
\ No newline at end of file
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
index 02af4374..a551b313 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
@@ -24,19 +24,20 @@ sealed class ItemDescriptor(val config: Config) {
      */
     var info: String? by config.string()
 
-    /**
-     * Additional attributes of an item. For example validation and widget parameters
-     *
-     * @return
-     */
-    var attributes by config.node()
-
     /**
      * True if the item is required
      *
      * @return
      */
     abstract var required: Boolean
+
+
+    /**
+     * Additional attributes of an item. For example validation and widget parameters
+     *
+     * @return
+     */
+    var attributes by config.node()
 }
 
 /**
@@ -166,12 +167,12 @@ class NodeDescriptor(config: Config = Config()) : ItemDescriptor(config) {
         value(name.toName(), block)
     }
 
-    companion object{
+    companion object {
 
         val ITEM_KEY = "item".asName()
         val IS_NODE_KEY = "@isNode".asName()
 
-        inline operator fun invoke(block: NodeDescriptor.()->Unit) = NodeDescriptor().apply(block)
+        inline operator fun invoke(block: NodeDescriptor.() -> Unit) = NodeDescriptor().apply(block)
 
         //TODO infer descriptor from spec
     }
@@ -251,9 +252,9 @@ class ValueDescriptor(config: Config = Config()) : ItemDescriptor(config) {
      * @return
      */
     var allowedValues: List<Value> by config.value().transform {
-        when{
+        when {
             it?.list != null -> it.list
-            type.size == 1 && type[0] === ValueType.BOOLEAN ->    listOf(True, False)
+            type.size == 1 && type[0] === ValueType.BOOLEAN -> listOf(True, False)
             else -> emptyList()
         }
     }
@@ -264,4 +265,14 @@ class ValueDescriptor(config: Config = Config()) : ItemDescriptor(config) {
     fun allow(vararg v: Any) {
         this.allowedValues = v.map { Value.of(it) }
     }
+}
+
+/**
+ * Merge two node descriptors into one using first one as primary
+ */
+operator fun NodeDescriptor.plus(other: NodeDescriptor): NodeDescriptor {
+    return NodeDescriptor().apply {
+        config.update(other.config)
+        config.update(this@plus.config)
+    }
 }
\ No newline at end of file

From 453a1bc7552ed19a8c5aebfcfbe64ba4d2aeff7a Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Wed, 22 Apr 2020 13:40:35 +0300
Subject: [PATCH 7/8] Remove reflection from common module

---
 dataforge-context/build.gradle.kts                          | 2 +-
 .../src/commonMain/kotlin/hep/dataforge/context/Context.kt  | 6 ++++--
 .../src/commonMain/kotlin/hep/dataforge/meta/Config.kt      | 2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/dataforge-context/build.gradle.kts b/dataforge-context/build.gradle.kts
index dd581254..261933fe 100644
--- a/dataforge-context/build.gradle.kts
+++ b/dataforge-context/build.gradle.kts
@@ -13,12 +13,12 @@ kotlin {
         val commonMain by getting {
             dependencies {
                 api(project(":dataforge-meta"))
-                api(kotlin("reflect"))
                 api("io.github.microutils:kotlin-logging-common:1.7.8")
             }
         }
         val jvmMain by getting {
             dependencies {
+                api(kotlin("reflect"))
                 api("io.github.microutils:kotlin-logging:1.7.8")
                 api("ch.qos.logback:logback-classic:1.2.3")
             }
diff --git a/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt b/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt
index 3db334c2..bf901991 100644
--- a/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt
+++ b/dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Context.kt
@@ -92,8 +92,10 @@ open class Context(
         config.action()
     }
 
-    override val coroutineContext: CoroutineContext = (parent ?: Global).coroutineContext.let { parenContext ->
-        parenContext + SupervisorJob(parenContext[Job])
+    override val coroutineContext: CoroutineContext by lazy {
+        (parent ?: Global).coroutineContext.let { parenContext ->
+            parenContext + SupervisorJob(parenContext[Job])
+        }
     }
 
     /**
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Config.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Config.kt
index 53a2e184..0ac29d86 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Config.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Config.kt
@@ -14,7 +14,7 @@ data class MetaListener(
 )
 
 interface ObservableMeta : Meta {
-    fun onChange(owner: Any?, action: (Name, MetaItem<*>?, MetaItem<*>?) -> Unit)
+    fun onChange(owner: Any?, action: (name: Name, oldItem: MetaItem<*>?, newItem: MetaItem<*>?) -> Unit)
     fun removeListener(owner: Any?)
 }
 

From fb559f456201f4af1d54a9156131b0175dd4e395 Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Sun, 17 May 2020 20:12:44 +0300
Subject: [PATCH 8/8] 0.1.8-dev-2

---
 build.gradle.kts                                       |  4 +++-
 dataforge-context/build.gradle.kts                     |  6 +++---
 .../kotlin/hep/dataforge/meta/Configurable.kt          |  7 +++++++
 .../kotlin/hep/dataforge/meta/ConfigurableDelegate.kt  |  4 ++--
 .../kotlin/hep/dataforge/meta/MutableMetaDelegate.kt   |  4 ++--
 .../hep/dataforge/meta/descriptors/ItemDescriptor.kt   | 10 ++++++++++
 6 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/build.gradle.kts b/build.gradle.kts
index 3395cacc..f87fced4 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,9 +1,10 @@
 
 plugins {
-    val toolsVersion = "0.4.2"
+    val toolsVersion = "0.5.5"
     id("scientifik.mpp") version toolsVersion apply false
     id("scientifik.jvm") version toolsVersion apply false
     id("scientifik.publish") version toolsVersion apply false
+    id("org.jetbrains.dokka") version "0.10.1"
 }
 
 val dataforgeVersion by extra("0.1.8-dev-2")
@@ -22,4 +23,5 @@ allprojects {
 
 subprojects {
     apply(plugin = "scientifik.publish")
+    apply(plugin = "org.jetbrains.dokka")
 }
\ No newline at end of file
diff --git a/dataforge-context/build.gradle.kts b/dataforge-context/build.gradle.kts
index 261933fe..3c13042d 100644
--- a/dataforge-context/build.gradle.kts
+++ b/dataforge-context/build.gradle.kts
@@ -13,19 +13,19 @@ kotlin {
         val commonMain by getting {
             dependencies {
                 api(project(":dataforge-meta"))
-                api("io.github.microutils:kotlin-logging-common:1.7.8")
+                api("io.github.microutils:kotlin-logging-common:1.7.9")
             }
         }
         val jvmMain by getting {
             dependencies {
                 api(kotlin("reflect"))
-                api("io.github.microutils:kotlin-logging:1.7.8")
+                api("io.github.microutils:kotlin-logging:1.7.9")
                 api("ch.qos.logback:logback-classic:1.2.3")
             }
         }
         val jsMain by getting {
             dependencies {
-                api("io.github.microutils:kotlin-logging-js:1.7.8")
+                api("io.github.microutils:kotlin-logging-js:1.7.9")
             }
         }
     }
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt
index 884c1c26..a078c37f 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Configurable.kt
@@ -50,6 +50,13 @@ interface Configurable : Described {
     }
 }
 
+/**
+ * Reset the property to its default value
+ */
+fun Configurable.resetProperty(name: Name) {
+    setProperty(name, null)
+}
+
 fun Configurable.getProperty(key: String) = getProperty(key.toName())
 
 fun Configurable.setProperty(name: Name, value: Value?) = setProperty(name, value?.let { MetaItem.ValueItem(value) })
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigurableDelegate.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigurableDelegate.kt
index 1999ced4..a94b3667 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigurableDelegate.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigurableDelegate.kt
@@ -201,8 +201,8 @@ fun Configurable.doubleArray(vararg doubles: Double, key: Name? = null): ReadWri
 
 /* Node delegates */
 
-fun Configurable.config(key: Name? = null): ReadWriteProperty<Any?, Config?> =
-    config.node(key)
+fun Configurable.config(default: Config? = null, key: Name? = null): ReadWriteProperty<Any?, Config?> =
+    config.node(default,key)
 
 fun Configurable.node(key: Name? = null): ReadWriteProperty<Any?, Meta?> = item(key).map(
     reader = { it.node },
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt
index 39a022f4..3230afbe 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaDelegate.kt
@@ -84,8 +84,8 @@ fun <M : MutableMeta<M>> M.boolean(default: Boolean? = null, key: Name? = null):
 fun <M : MutableMeta<M>> M.number(default: Number? = null, key: Name? = null): ReadWriteProperty<Any?, Number?> =
     item(default, key).transform { it.number }
 
-inline fun <reified M : MutableMeta<M>> M.node(key: Name? = null) =
-    item(this, key).transform { it.node as? M }
+inline fun <reified M : MutableMeta<M>> M.node(default: M? = null, key: Name? = null) =
+    item(default, key = key).transform { it.node as? M }
 
 @JvmName("safeString")
 fun <M : MutableMeta<M>> M.string(default: String, key: Name? = null) =
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
index a551b313..7f748ff2 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/ItemDescriptor.kt
@@ -47,10 +47,20 @@ fun ItemDescriptor.attributes(block: Config.() -> Unit) {
     (attributes ?: Config().also { this.attributes = it }).apply(block)
 }
 
+/**
+ * Set specific attribute in the descriptor
+ */
+fun ItemDescriptor.setAttribute(name: Name, value: Any?) {
+    attributes {
+        set(name, value)
+    }
+}
+
 /**
  * Check if given item suits the descriptor
  */
 fun ItemDescriptor.validateItem(item: MetaItem<*>?): Boolean {
+    if (item == null) return !required
     return when (this) {
         is ValueDescriptor -> isAllowedValue(item.value ?: return false)
         is NodeDescriptor -> items.all { (key, d) ->