Moved to K1.3.

Removed MultiNodeItems and replaced same name siblings by queries.
Laminate merge.

build.gradle

@@ -1,12 +1,10 @@
 buildscript {
-    ext.kotlin_version = '1.3.0-rc-190'
+    ext.kotlin_version = '1.3.0'
-    ext.serialization_version = '0.8.3-rc13'
+    ext.serialization_version = '0.9.0'
-    ext.kotlinx_io_version = '0.1.0-alpha-24-rc13'
+    ext.kotlinx_io_version = '0.1.0-beta-1'
+
     repositories {
         jcenter()
-        maven {
-            url = "http://dl.bintray.com/kotlin/kotlin-eap"
-        }
     }
 
     dependencies {

dataforge-meta-io/build.gradle

@@ -2,10 +2,11 @@ plugins {
     id 'kotlin-multiplatform'
     //id 'kotlinx-serialization'
 }
+
 repositories {
-    maven { url = 'http://dl.bintray.com/kotlin/kotlin-eap' }
+    jcenter()
-    mavenCentral()
 }
+
 kotlin {
     targets {
         fromPreset(presets.jvm, 'jvm')

dataforge-meta-io/src/commonMain/kotlin/hep/dataforge/meta/io/MetaFormat.kt

@@ -54,7 +54,7 @@ object BinaryMetaFormat : MetaFormat {
     }
 
     override fun read(input: Input): Meta {
-        return (input.readMetaItem() as MetaItem.SingleNodeItem).node
+        return (input.readMetaItem() as MetaItem.NodeItem).node
     }
 
     private fun Output.writeChar(char: Char) = writeByte(char.toByte())
@@ -115,21 +115,14 @@ object BinaryMetaFormat : MetaFormat {
         writeChar('M')
         writeInt(meta.items.size)
         meta.items.forEach { (key, item) ->
-            writeString(key)
+            writeString(key.toString())
             when (item) {
                 is MetaItem.ValueItem -> {
                     writeValue(item.value)
                 }
-                is MetaItem.SingleNodeItem -> {
+                is MetaItem.NodeItem -> {
                     writeMeta(item.node)
                 }
-                is MetaItem.MultiNodeItem -> {
-                    writeChar('#')
-                    writeInt(item.nodes.size)
-                    item.nodes.forEach {
-                        writeMeta(it)
-                    }
-                }
             }
         }
     }
@@ -165,12 +158,7 @@ object BinaryMetaFormat : MetaFormat {
                         set(name, item)
                     }
                 }
-                MetaItem.SingleNodeItem(meta)
+                MetaItem.NodeItem(meta)
-            }
-            '#' -> {
-                val length = readInt()
-                val nodes = (1..length).map { (readMetaItem() as MetaItem.SingleNodeItem).node }
-                MetaItem.MultiNodeItem(nodes)
             }
             else -> error("Unknown serialization key character: $keyChar")
         }

dataforge-meta-io/src/jsMain/kotlin/hep/dataforge/meta/io/JSMeta.kt

@@ -3,13 +3,14 @@ package hep.dataforge.meta.io
 import hep.dataforge.meta.Meta
 import hep.dataforge.meta.MetaItem
 import hep.dataforge.meta.Value
+import hep.dataforge.names.NameToken
 
 /**
  * Represent any js object as meta
  */
 class JSMeta(val obj: Any) : Meta {
-    override val items: Map<String, MetaItem<out Meta>>
+    override val items: Map<NameToken, MetaItem<out Meta>>
-        get() = listKeys(obj).associateWith { convert(js("obj[it]")) }
+        get() = listKeys(obj).map { NameToken(it) }.associateWith { convert(js("obj[it]")) }
 
     private fun listKeys(obj: Any): List<String> = js("Object").keys(obj) as List<String>
 
@@ -22,15 +23,9 @@ class JSMeta(val obj: Any) : Meta {
             null, isPrimitive(obj), is Number, is String, is Boolean -> MetaItem.ValueItem<JSMeta>(Value.of(obj))
             isList(obj) -> {
                 val list = obj as List<*>
-                //if first value is primitive, treat as value
-                if (isPrimitive(list.first())) {
                 MetaItem.ValueItem<JSMeta>(Value.of(list))
-                } else {
-                    //else treat as meta list
-                    MetaItem.MultiNodeItem(list.map { JSMeta(it!!) })
             }
-            }
+            else -> MetaItem.NodeItem(JSMeta(obj))
-            else -> MetaItem.SingleNodeItem(JSMeta(obj))
         }
     }
 }

dataforge-meta-io/src/jvmMain/kotlin/hep/dataforge/meta/io/JSONMetaFormat.kt

@@ -34,13 +34,8 @@ private fun Meta.toJson(): JsonObject {
     val builder = JsonObject()
     items.forEach { name, item ->
         when (item) {
-            is MetaItem.ValueItem -> builder[name] = item.value.toJson()
+            is MetaItem.ValueItem -> builder[name.toString()] = item.value.toJson()
-            is MetaItem.SingleNodeItem -> builder[name] = item.node.toJson()
+            is MetaItem.NodeItem -> builder[name.toString()] = item.node.toJson()
-            is MetaItem.MultiNodeItem -> {
-                val array = JsonArray()
-                item.nodes.forEach { array.add(it.toJson()) }
-                builder[name] = array
-            }
         }
     }
     return builder

dataforge-meta/build.gradle

@@ -1,10 +1,11 @@
 plugins {
     id 'kotlin-multiplatform'
 }
+
 repositories {
-    maven { url = 'http://dl.bintray.com/kotlin/kotlin-eap' }
+    jcenter()
-    mavenCentral()
 }
+
 kotlin {
     targets {
         fromPreset(presets.jvm, 'jvm')

dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Config.kt

@@ -22,8 +22,7 @@ fun Meta.toConfig(): Config = this as? Config ?: Config().also { builder ->
         val item = entry.value
         builder[entry.key] = when (item) {
             is MetaItem.ValueItem -> MetaItem.ValueItem(item.value)
-            is MetaItem.SingleNodeItem -> MetaItem.SingleNodeItem(item.node.toConfig())
+            is MetaItem.NodeItem -> MetaItem.NodeItem(item.node.toConfig())
-            is MetaItem.MultiNodeItem -> MetaItem.MultiNodeItem(item.nodes.map { it.toConfig() })
         }
     }
 }

dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Laminate.kt

@@ -0,0 +1,72 @@
+package hep.dataforge.meta
+
+import hep.dataforge.names.NameToken
+
+/**
+ * A meta laminate consisting of multiple immutable meta layers. For mutable front layer, use [StyledConfig].
+ *
+ *
+ */
+class Laminate(val layers: List<Meta>) : Meta {
+
+    override val items: Map<NameToken, MetaItem<out Meta>>
+        get() = layers.map { it.items.keys }.flatten().associateWith { key ->
+            layers.asSequence().map { it.items[key] }.filterNotNull().let(replaceRule)
+        }
+
+    /**
+     * Generate sealed meta using [mergeRule]
+     */
+    fun merge(): SealedMeta {
+        val items = layers.map { it.items.keys }.flatten().associateWith { key ->
+            layers.asSequence().map { it.items[key] }.filterNotNull().merge()
+        }
+        return SealedMeta(items)
+    }
+
+    companion object {
+
+        /**
+         * The default rule which always uses the first found item in sequence alongside with its children.
+         *
+         * TODO add picture
+         */
+        val replaceRule: (Sequence<MetaItem<*>>) -> MetaItem<SealedMeta> = { it.first().seal() }
+
+        private fun Sequence<MetaItem<*>>.merge(): MetaItem<SealedMeta> {
+            return when {
+                all { it is MetaItem.ValueItem } -> //If all items are values, take first
+                    first().seal()
+                all { it is MetaItem.NodeItem } -> {
+                    //list nodes in item
+                    val nodes = map { it.node }
+                    //represent as key->value entries
+                    val entries = nodes.flatMap { it.items.entries.asSequence() }
+                    //group by keys
+                    val groups = entries.groupBy { it.key }
+                    // recursively apply the rule
+                    val items = groups.mapValues { entry ->
+                        entry.value.asSequence().map { it.value }.merge()
+                    }
+                    MetaItem.NodeItem(SealedMeta(items))
+
+                }
+                else -> map {
+                    when (it) {
+                        is MetaItem.ValueItem -> MetaItem.NodeItem(buildMeta { Meta.VALUE_KEY to it.value })
+                        is MetaItem.NodeItem -> it
+                    }
+                }.merge()
+            }
+        }
+
+
+        /**
+         * The values a replaced but meta children are joined
+         * TODO add picture
+         */
+        val mergeRule: (Sequence<MetaItem<*>>) -> MetaItem<SealedMeta> = { it.merge() }
+    }
+}
+
+//TODO add custom rules for Laminate merge

dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt

@@ -1,47 +1,57 @@
 package hep.dataforge.meta
 
+import hep.dataforge.meta.Meta.Companion.VALUE_KEY
+import hep.dataforge.meta.MetaItem.NodeItem
+import hep.dataforge.meta.MetaItem.ValueItem
 import hep.dataforge.names.Name
+import hep.dataforge.names.NameToken
 import hep.dataforge.names.toName
 
 /**
  * A member of the meta tree. Could be represented as one of following:
- * * a value
+ * * a [ValueItem] (leaf)
- * * a single node
+ * * a [NodeItem] (node)
- * * a list of nodes
  */
 sealed class MetaItem<M : Meta> {
     data class ValueItem<M : Meta>(val value: Value) : MetaItem<M>()
-    data class SingleNodeItem<M : Meta>(val node: M) : MetaItem<M>()
+    data class NodeItem<M : Meta>(val node: M) : MetaItem<M>()
-    data class MultiNodeItem<M : Meta>(val nodes: List<M>) : MetaItem<M>()
-}
-
-operator fun <M : Meta> List<M>.get(query: String): M? {
-    return if (query.isEmpty()) {
-        first()
-    } else {
-        //TODO add custom key queries
-        get(query.toInt())
-    }
 }
 
 /**
  * Generic meta tree representation. Elements are [MetaItem] objects that could be represented by three different entities:
  *  * [MetaItem.ValueItem] (leaf)
- *  * [MetaItem.SingleNodeItem] single node
+ *  * [MetaItem.NodeItem] single node
- *  * [MetaItem.MultiNodeItem] multi-value node
+ *
+ *   * Same name siblings are supported via elements with the same [Name] but different queries
  */
 interface Meta {
-    val items: Map<String, MetaItem<out Meta>>
+    val items: Map<NameToken, MetaItem<out Meta>>
-}
 
-operator fun Meta.get(name: Name): MetaItem<out Meta>? {
+    companion object {
-    return when (name.length) {
+        /**
-        0 -> error("Can't resolve element from empty name")
+         * A key for single value node
-        1 -> items[name.first()!!.body]
+         */
-        else -> name.first()!!.let { token -> items[token.body]?.nodes?.get(token.query) }?.get(name.cutFirst())
+        const val VALUE_KEY = "@value"
     }
 }
 
+/**
+ * Fast [String]-based accessor for item map
+ */
+operator fun <T> Map<NameToken, T>.get(body: String, query: String = ""): T? = get(NameToken(body, query))
+
+operator fun Meta.get(name: Name): MetaItem<out Meta>? {
+    return name.first()?.let { token ->
+        val tail = name.cutFirst()
+        when (tail.length) {
+            0 -> items[token]
+            else -> items[token]?.node?.get(tail)
+        }
+    }
+}
+
+operator fun Meta.get(token: NameToken): MetaItem<out Meta>? = items[token]
+
 //TODO create Java helper for meta operations
 operator fun Meta.get(key: String): MetaItem<out Meta>? = get(key.toName())
 
@@ -49,13 +59,15 @@ operator fun Meta.get(key: String): MetaItem<out Meta>? = get(key.toName())
  * A meta node that ensures that all of its descendants has at least the same type
  */
 abstract class MetaNode<M : MetaNode<M>> : Meta {
-    abstract override val items: Map<String, MetaItem<M>>
+    abstract override val items: Map<NameToken, MetaItem<M>>
 
     operator fun get(name: Name): MetaItem<M>? {
-        return when (name.length) {
+        return name.first()?.let { token ->
-            0 -> error("Can't resolve element from empty name")
+            val tail = name.cutFirst()
-            1 -> items[name.first()!!.body]
+            when (tail.length) {
-            else -> name.first()!!.let { token -> items[token.body]?.nodes?.get(token.query) }?.get(name.cutFirst())
+                0 -> items[token]
+                else -> items[token]?.node?.get(tail)
+            }
         }
     }
 
@@ -78,34 +90,19 @@ abstract class MetaNode<M : MetaNode<M>> : Meta {
  *
  * If the argument is possibly mutable node, it is copied on creation
  */
-class SealedMeta internal constructor(override val items: Map<String, MetaItem<SealedMeta>>) : MetaNode<SealedMeta>() {
+class SealedMeta internal constructor(override val items: Map<NameToken, MetaItem<SealedMeta>>) : MetaNode<SealedMeta>()
-
-    companion object {
-        fun seal(meta: Meta): SealedMeta {
-            val items = if (meta is SealedMeta) {
-                meta.items
-            } else {
-                meta.items.mapValues { entry ->
-                    val item = entry.value
-                    when (item) {
-                        is MetaItem.ValueItem -> MetaItem.ValueItem(item.value)
-                        is MetaItem.SingleNodeItem -> MetaItem.SingleNodeItem(seal(item.node))
-                        is MetaItem.MultiNodeItem -> MetaItem.MultiNodeItem(item.nodes.map { seal(it) })
-                    }
-                }
-            }
-            return SealedMeta(items)
-        }
-    }
-}
-
 /**
  * Generate sealed node from [this]. If it is already sealed return it as is
  */
-fun Meta.seal(): SealedMeta = this as? SealedMeta ?: SealedMeta.seal(this)
+fun Meta.seal(): SealedMeta = this as? SealedMeta ?: SealedMeta(items.mapValues { entry -> entry.value.seal() })
+
+fun MetaItem<*>.seal(): MetaItem<SealedMeta> = when (this) {
+    is MetaItem.ValueItem -> MetaItem.ValueItem(value)
+    is MetaItem.NodeItem -> MetaItem.NodeItem(node.seal())
+}
 
 object EmptyMeta : Meta {
-    override val items: Map<String, MetaItem<out Meta>> = emptyMap()
+    override val items: Map<NameToken, MetaItem<out Meta>> = emptyMap()
 }
 
 /**
@@ -113,40 +110,23 @@ object EmptyMeta : Meta {
  */
 
 val MetaItem<*>.value
-    get() = (this as? MetaItem.ValueItem)?.value ?: error("Trying to interpret node meta item as value item")
+    get() = (this as? MetaItem.ValueItem)?.value
+            ?: (this.node[VALUE_KEY] as? MetaItem.ValueItem)?.value
+            ?: error("Trying to interpret node meta item as value item")
 val MetaItem<*>.string get() = value.string
 val MetaItem<*>.boolean get() = value.boolean
 val MetaItem<*>.number get() = value.number
 val MetaItem<*>.double get() = number.toDouble()
 val MetaItem<*>.int get() = number.toInt()
 val MetaItem<*>.long get() = number.toLong()
+val MetaItem<*>.short get() = number.toShort()
 
 val <M : Meta> MetaItem<M>.node: M
     get() = when (this) {
         is MetaItem.ValueItem -> error("Trying to interpret value meta item as node item")
-        is MetaItem.SingleNodeItem -> node
+        is MetaItem.NodeItem -> node
-        is MetaItem.MultiNodeItem -> nodes.first()
     }
 
-/**
- * Utility method to access item content as list of nodes.
- * Returns empty list if it is value item.
- */
-val <M : Meta> MetaItem<M>.nodes: List<M>
-    get() = when (this) {
-        is MetaItem.ValueItem -> emptyList()//error("Trying to interpret value meta item as node item")
-        is MetaItem.SingleNodeItem -> listOf(node)
-        is MetaItem.MultiNodeItem -> nodes
-    }
-
-fun <M : Meta> MetaItem<M>.indexOf(meta: M): Int {
-    return when (this) {
-        is MetaItem.ValueItem -> -1
-        is MetaItem.SingleNodeItem -> if (node == meta) 0 else -1
-        is MetaItem.MultiNodeItem -> nodes.indexOf(meta)
-    }
-}
-
 /**
  * Generic meta-holder object
  */

dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MetaBuilder.kt

@@ -37,9 +37,8 @@ fun Meta.builder(): MetaBuilder {
         items.mapValues { entry ->
             val item = entry.value
             builder[entry.key] = when (item) {
-                is MetaItem.ValueItem -> MetaItem.ValueItem(item.value)
+                is MetaItem.ValueItem -> MetaItem.ValueItem<MetaBuilder>(item.value)
-                is MetaItem.SingleNodeItem -> MetaItem.SingleNodeItem(item.node.builder())
+                is MetaItem.NodeItem -> MetaItem.NodeItem(item.node.builder())
-                is MetaItem.MultiNodeItem -> MetaItem.MultiNodeItem(item.nodes.map { it.builder() })
             }
         }
     }

dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMetaNode.kt

@@ -1,6 +1,7 @@
 package hep.dataforge.meta
 
 import hep.dataforge.names.Name
+import hep.dataforge.names.NameToken
 import hep.dataforge.names.plus
 import hep.dataforge.names.toName
 
@@ -10,14 +11,16 @@ class MetaListener(val owner: Any? = null, val action: (name: Name, oldItem: Met
 
 
 interface MutableMeta<M : MutableMeta<M>> : Meta {
-    override val items: Map<String, MetaItem<M>>
+    override val items: Map<NameToken, MetaItem<M>>
     operator fun set(name: Name, item: MetaItem<M>?)
     fun onChange(owner: Any? = null, action: (Name, MetaItem<*>?, MetaItem<*>?) -> Unit)
     fun removeListener(owner: Any)
 }
 
 /**
- * A mutable meta node with attachable change listener
+ * A mutable meta node with attachable change listener.
+ *
+ * Changes in Meta are not thread safe.
  */
 abstract class MutableMetaNode<M : MutableMetaNode<M>> : MetaNode<M>(), MutableMeta<M> {
     private val listeners = HashSet<MetaListener>()
@@ -36,26 +39,24 @@ abstract class MutableMetaNode<M : MutableMetaNode<M>> : MetaNode<M>(), MutableM
         listeners.removeAll { it.owner === owner }
     }
 
-    private val _items: MutableMap<String, MetaItem<M>> = HashMap()
+    private val _items: MutableMap<NameToken, MetaItem<M>> = HashMap()
 
-    override val items: Map<String, MetaItem<M>>
+    override val items: Map<NameToken, MetaItem<M>>
         get() = _items
 
     protected fun itemChanged(name: Name, oldItem: MetaItem<*>?, newItem: MetaItem<*>?) {
         listeners.forEach { it(name, oldItem, newItem) }
     }
 
-    protected open fun replaceItem(key: String, oldItem: MetaItem<M>?, newItem: MetaItem<M>?) {
+    protected open fun replaceItem(key: NameToken, oldItem: MetaItem<M>?, newItem: MetaItem<M>?) {
         if (newItem == null) {
             _items.remove(key)
-            oldItem?.nodes?.forEach {
+            oldItem?.node?.removeListener(this)
-                it.removeListener(this)
-            }
         } else {
             _items[key] = newItem
-            newItem.nodes.forEach {
+            if(newItem is MetaItem.NodeItem) {
-                it.onChange(this) { name, oldItem, newItem ->
+                newItem.node.onChange(this) { name, oldChild, newChild ->
-                    itemChanged(key.toName() + name, oldItem, newItem)
+                    itemChanged(key + name, oldChild, newChild)
                 }
             }
         }
@@ -79,14 +80,13 @@ abstract class MutableMetaNode<M : MutableMetaNode<M>> : MetaNode<M>(), MutableM
             0 -> error("Can't set meta item for empty name")
             1 -> {
                 val token = name.first()!!
-                if (token.hasQuery()) TODO("Queries are not supported in set operations on meta")
+                replaceItem(token, get(name), item)
-                replaceItem(token.body, get(name), item)
             }
             else -> {
                 val token = name.first()!!
                 //get existing or create new node. Query is ignored for new node
-                val child = this.items[token.body]?.nodes?.get(token.query)
+                val child = this.items[token]?.node
-                        ?: empty().also { this[token.body.toName()] = MetaItem.SingleNodeItem(it) }
+                        ?: empty().also { this[token.body.toName()] = MetaItem.NodeItem(it) }
                 child[name.cutFirst()] = item
             }
         }
@@ -99,13 +99,11 @@ fun <M : MutableMeta<M>> M.remove(name: Name) = set(name, null)
 fun <M : MutableMeta<M>> M.remove(name: String) = remove(name.toName())
 
 operator fun <M : MutableMeta<M>> M.set(name: Name, value: Value) = set(name, MetaItem.ValueItem(value))
-operator fun <M : MutableMetaNode<M>> M.set(name: Name, meta: Meta) = set(name, MetaItem.SingleNodeItem(wrap(name, meta)))
+operator fun <M : MutableMetaNode<M>> M.set(name: Name, meta: Meta) = set(name, MetaItem.NodeItem(wrap(name, meta)))
-operator fun <M : MutableMetaNode<M>> M.set(name: Name, metas: List<Meta>) = set(name, MetaItem.MultiNodeItem(metas.map { wrap(name, it) }))
-
 operator fun <M : MutableMeta<M>> M.set(name: String, item: MetaItem<M>) = set(name.toName(), item)
 operator fun <M : MutableMeta<M>> M.set(name: String, value: Value) = set(name.toName(), MetaItem.ValueItem(value))
 operator fun <M : MutableMetaNode<M>> M.set(name: String, meta: Meta) = set(name.toName(), meta)
-operator fun <M : MutableMetaNode<M>> M.set(name: String, metas: List<Meta>) = set(name.toName(), metas)
+operator fun <M : MutableMeta<M>> M.set(token: NameToken, item: MetaItem<M>?) = set(token.toName(), item)
 
 
 /**
@@ -129,19 +127,23 @@ fun <M : MutableMetaNode<M>> M.update(meta: Meta) {
     meta.items.forEach { entry ->
         val value = entry.value
         when (value) {
-            is MetaItem.ValueItem -> this[entry.key] = value.value
+            is MetaItem.ValueItem -> this[entry.key.toName()] = value.value
-            is MetaItem.SingleNodeItem -> (this[entry.key] as? MetaItem.SingleNodeItem)
+            is MetaItem.NodeItem -> (this[entry.key.toName()] as? MetaItem.NodeItem)?.node?.update(value.node)
-                    ?.node?.update(value.node) ?: kotlin.run { this[entry.key] = value.node }
+                    ?: run { this[entry.key.toName()] = value.node }
-            is MetaItem.MultiNodeItem -> {
-                val existing = this[entry.key]
-                if (existing is MetaItem.MultiNodeItem && existing.nodes.size == value.nodes.size) {
-                    existing.nodes.forEachIndexed { index, m ->
-                        m.update(value.nodes[index])
-                    }
-                } else {
-                    this[entry.key] = value.nodes
-                }
-            }
         }
     }
 }
+
+// Same name siblings generation
+
+fun <M : MutableMetaNode<M>> M.setIndexed(name: Name, metas: Iterable<Meta>, queryFactory: (Int) -> String = { it.toString() }) {
+    val tokens = name.tokens.toMutableList()
+    val last = tokens.last()
+    metas.forEachIndexed { index, meta ->
+        val indexedToken = NameToken(last.body, last.query + queryFactory(index))
+        tokens[tokens.lastIndex] = indexedToken
+        set(Name(tokens), meta)
+    }
+}
+
+operator fun <M : MutableMetaNode<M>> M.set(name: Name, metas: Iterable<Meta>) = setIndexed(name, metas)

dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Specification.kt

@@ -4,7 +4,7 @@ package hep.dataforge.meta
  * Marker interface for specifications
  */
 interface Specification: Configurable{
-    operator fun get(name: String): MetaItem<Config>? = config.get(name)
+    operator fun get(name: String): MetaItem<Config>? = config[name]
 }
 
 /**

dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Styleable.kt

@@ -1,6 +1,7 @@
 package hep.dataforge.meta
 
 import hep.dataforge.names.Name
+import hep.dataforge.names.NameToken
 import hep.dataforge.names.toName
 
 /**
@@ -27,12 +28,11 @@ class StyledConfig(val config: Config, style: Meta = EmptyMeta) : Config() {
         when (item) {
             null -> config.remove(name)
             is MetaItem.ValueItem -> config[name] = item.value
-            is MetaItem.SingleNodeItem -> config[name] = item.node
+            is MetaItem.NodeItem -> config[name] = item.node
-            is MetaItem.MultiNodeItem -> config[name] = item.nodes
         }
     }
 
-    override val items: Map<String, MetaItem<Config>>
+    override val items: Map<NameToken, MetaItem<Config>>
         get() = (config.items.keys + style.items.keys).associate { key ->
             val value = config.items[key]
             val styleValue = style[key]
@@ -40,16 +40,12 @@ class StyledConfig(val config: Config, style: Meta = EmptyMeta) : Config() {
                 null -> when (styleValue) {
                     null -> error("Should be unreachable")
                     is MetaItem.ValueItem -> MetaItem.ValueItem(styleValue.value)
-                    is MetaItem.SingleNodeItem -> MetaItem.SingleNodeItem<Config>(StyledConfig(config.empty(), styleValue.node))
+                    is MetaItem.NodeItem -> MetaItem.NodeItem<Config>(StyledConfig(config.empty(), styleValue.node))
-                    is MetaItem.MultiNodeItem -> MetaItem.MultiNodeItem<Config>(styleValue.nodes.map { StyledConfig(config.empty(), it) })
                 }
                 is MetaItem.ValueItem -> MetaItem.ValueItem(value.value)
-                is MetaItem.SingleNodeItem -> MetaItem.SingleNodeItem(
+                is MetaItem.NodeItem -> MetaItem.NodeItem(
                         StyledConfig(value.node, styleValue?.node ?: EmptyMeta)
                 )
-                is MetaItem.MultiNodeItem -> MetaItem.MultiNodeItem(value.nodes.map {
-                    StyledConfig(it, styleValue?.node ?: EmptyMeta)
-                })
             }
             key to item
         }

dataforge-meta/src/commonMain/kotlin/hep/dataforge/names/Name.kt

@@ -58,7 +58,7 @@ class Name internal constructor(val tokens: List<NameToken>) {
  * Following symbols are prohibited in name tokens: `{}.:\`.
  * A name token could have appendix in square brackets called *query*
  */
-data class NameToken internal constructor(val body: String, val query: String) {
+data class NameToken(val body: String, val query: String = "") {
 
     init {
         if (body.isEmpty()) error("Syntax error: Name token body is empty")
@@ -108,6 +108,8 @@ fun String.toName(): Name {
     return Name(tokens.toList())
 }
 
+operator fun NameToken.plus(other: Name): Name = Name(listOf(this) + other.tokens)
+
 operator fun Name.plus(other: Name): Name = Name(this.tokens + other.tokens)
 
 operator fun Name.plus(other: String): Name = this + other.toName()

settings.gradle

@@ -17,7 +17,6 @@ pluginManagement {
     }
 
     repositories {
-        maven { url = 'http://dl.bintray.com/kotlin/kotlin-eap' }
         mavenCentral()
         maven { url = 'https://plugins.gradle.org/m2/' }
     }