IrComposite - block introducing immediate declarations to the surrounding scope.

E.g., destructuring declaration is represented as IrComposite.

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrBlock.kt

@@ -16,13 +16,17 @@
 
 package org.jetbrains.kotlin.ir.expressions
 
-import org.jetbrains.kotlin.ir.IrStatement
-import org.jetbrains.kotlin.ir.detach
-
-
-interface IrBlock : IrExpression {
+interface IrContainerExpression : IrExpression, IrStatementContainer {
     val operator: IrOperator?
-
-    val statements: List<IrStatement>
+    val isTransparentScope: Boolean
 }
 
+interface IrBlock : IrContainerExpression {
+    override val isTransparentScope: Boolean
+        get() = false
+}
+
+interface IrComposite : IrContainerExpression {
+    override val isTransparentScope: Boolean
+        get() = true
+}

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrBody.kt

@@ -25,10 +25,12 @@ interface IrExpressionBody : IrBody {
     var expression: IrExpression
 }
 
-interface IrBlockBody : IrBody {
+interface IrStatementContainer {
     val statements: List<IrStatement>
 }
 
+interface IrBlockBody : IrBody, IrStatementContainer
+
 interface IrSyntheticBody : IrBody {
     val kind: IrSyntheticBodyKind
 }

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrBlockImpl.kt

@@ -16,49 +16,20 @@
 
 package org.jetbrains.kotlin.ir.expressions.impl
 
-import org.jetbrains.kotlin.ir.*
+import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.detach
 import org.jetbrains.kotlin.ir.expressions.IrBlock
 import org.jetbrains.kotlin.ir.expressions.IrOperator
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 import org.jetbrains.kotlin.types.KotlinType
-import java.util.*
 
-class IrBlockImpl(startOffset: Int, endOffset: Int, type: KotlinType, override val operator: IrOperator? = null):
-        IrExpressionBase(startOffset, endOffset, type), IrBlock {
+class IrBlockImpl(startOffset: Int, endOffset: Int, type: KotlinType, operator: IrOperator? = null):
+        IrContainerExpressionBase(startOffset, endOffset, type, operator), IrBlock {
     constructor(startOffset: Int, endOffset: Int, type: KotlinType, operator: IrOperator?, statements: List<IrStatement>) :
             this(startOffset, endOffset, type, operator) {
         addAll(statements)
     }
 
-    override val statements: MutableList<IrStatement> = ArrayList(2)
-
-    fun addStatement(statement: IrStatement) {
-        statement.assertDetached()
-        statement.setTreeLocation(this, statements.size)
-        statements.add(statement)
-    }
-
-    fun addAll(newStatements: List<IrStatement>) {
-        newStatements.forEach { it.assertDetached() }
-        val originalSize = this.statements.size
-        this.statements.addAll(newStatements)
-        newStatements.forEachIndexed { i, irStatement ->
-            irStatement.setTreeLocation(this, originalSize + i)
-        }
-    }
-
-    override fun getChild(slot: Int): IrElement? =
-            statements.getOrNull(slot)
-
-    override fun replaceChild(slot: Int, newChild: IrElement) {
-        if (slot < 0 || slot >= statements.size) throwNoSuchSlot(slot)
-
-        newChild.assertDetached()
-        statements[slot].detach()
-        statements[slot] = newChild.assertCast()
-        newChild.setTreeLocation(this, slot)
-    }
-
     override fun <R, D> accept(visitor: IrElementVisitor<R, D>, data: D): R =
             visitor.visitBlock(this, data)
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrCompositeImpl.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2010-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.ir.expressions.impl
+
+import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.expressions.IrComposite
+import org.jetbrains.kotlin.ir.expressions.IrOperator
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
+import org.jetbrains.kotlin.types.KotlinType
+
+
+class IrCompositeImpl(startOffset: Int, endOffset: Int, type: KotlinType, operator: IrOperator? = null) :
+        IrContainerExpressionBase(startOffset, endOffset, type, operator), IrComposite {
+    constructor(startOffset: Int, endOffset: Int, type: KotlinType, operator: IrOperator?, statements: List<IrStatement>) :
+            this(startOffset, endOffset, type, operator) {
+        addAll(statements)
+    }
+
+    override fun <R, D> accept(visitor: IrElementVisitor<R, D>, data: D): R =
+            visitor.visitComposite(this, data)
+
+    override fun <D> acceptChildren(visitor: IrElementVisitor<Unit, D>, data: D) {
+        statements.forEach { it.accept(visitor, data) }
+    }
+}

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrContainerExpressionBase.kt

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2010-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.ir.expressions.impl
+
+import org.jetbrains.kotlin.ir.*
+import org.jetbrains.kotlin.ir.expressions.IrOperator
+import org.jetbrains.kotlin.ir.expressions.IrContainerExpression
+import org.jetbrains.kotlin.types.KotlinType
+import java.util.*
+
+abstract class IrContainerExpressionBase(startOffset: Int, endOffset: Int, type: KotlinType, override val operator: IrOperator? = null):
+        IrExpressionBase(startOffset, endOffset, type), IrContainerExpression {
+    override val statements: MutableList<IrStatement> = ArrayList(2)
+
+    fun addStatement(statement: IrStatement) {
+        statement.assertDetached()
+        statement.setTreeLocation(this, statements.size)
+        statements.add(statement)
+    }
+
+    fun addAll(newStatements: List<IrStatement>) {
+        newStatements.forEach { it.assertDetached() }
+        val originalSize = this.statements.size
+        this.statements.addAll(newStatements)
+        newStatements.forEachIndexed { i, irStatement ->
+            irStatement.setTreeLocation(this, originalSize + i)
+        }
+    }
+
+    override fun getChild(slot: Int): IrElement? =
+            statements.getOrNull(slot)
+
+    override fun replaceChild(slot: Int, newChild: IrElement) {
+        if (slot < 0 || slot >= statements.size) throwNoSuchSlot(slot)
+
+        newChild.assertDetached()
+        statements[slot].detach()
+        statements[slot] = newChild.assertCast()
+        newChild.setTreeLocation(this, slot)
+    }
+}

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/RenderIrElement.kt

@@ -102,6 +102,9 @@ class RenderIrElementVisitor : IrElementVisitor<String, Nothing?> {
     override fun visitBlock(expression: IrBlock, data: Nothing?): String =
             "BLOCK type=${expression.type.render()} operator=${expression.operator}"
 
+    override fun visitComposite(expression: IrComposite, data: Nothing?): String =
+            "COMPOSITE type=${expression.type.render()} operator=${expression.operator}"
+
     override fun visitReturn(expression: IrReturn, data: Nothing?): String =
             "RETURN type=${expression.type.render()} from='${expression.returnTarget.ref()}'"
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitor.kt

@@ -52,7 +52,9 @@ interface IrElementVisitor<out R, in D> {
     fun visitVararg(expression: IrVararg, data: D) = visitExpression(expression, data)
     fun visitSpreadElement(spread: IrSpreadElement, data: D) = visitElement(spread, data)
 
-    fun visitBlock(expression: IrBlock, data: D) = visitExpression(expression, data)
+    fun visitContainerExpression(expression: IrContainerExpression, data: D) = visitExpression(expression, data)
+    fun visitBlock(expression: IrBlock, data: D) = visitContainerExpression(expression, data)
+    fun visitComposite(expression: IrComposite, data: D) = visitContainerExpression(expression, data)
     fun visitStringConcatenation(expression: IrStringConcatenation, data: D) = visitExpression(expression, data)
     fun visitThisReference(expression: IrThisReference, data: D) = visitExpression(expression, data)
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitorVoid.kt

@@ -102,7 +102,13 @@ interface IrElementVisitorVoid : IrElementVisitor<Unit, Nothing?> {
     fun visitSpreadElement(spread: IrSpreadElement) = visitElement(spread)
     override fun visitSpreadElement(spread: IrSpreadElement, data: Nothing?) = visitSpreadElement(spread)
 
-    fun visitBlock(expression: IrBlock) = visitExpression(expression)
+    fun visitContainerExpression(expression: IrContainerExpression) = visitExpression(expression)
+    override fun visitContainerExpression(expression: IrContainerExpression, data: Nothing?) = visitContainerExpression(expression)
+
+    fun visitComposite(expression: IrComposite) = visitContainerExpression(expression)
+    override fun visitComposite(expression: IrComposite, data: Nothing?) = visitComposite(expression)
+
+    fun visitBlock(expression: IrBlock) = visitContainerExpression(expression)
     override fun visitBlock(expression: IrBlock, data: Nothing?) = visitBlock(expression)
 
     fun visitStringConcatenation(expression: IrStringConcatenation) = visitExpression(expression)