From 3aa9079ea217b1b5492e22562ee81a47263d2a50 Mon Sep 17 00:00:00 2001
From: Dmitry Jemerov <yole@jetbrains.com>
Date: Fri, 15 Apr 2011 17:29:22 +0200
Subject: [PATCH] not yet working code for for..in loop over Java arrays

---
 .../jet/codegen/ExpressionCodegen.java        | 49 +++++++++++++++++++
 .../org/jetbrains/jet/codegen/FrameMap.java   |  8 +++
 .../jet/lang/resolve/BindingContext.java      |  1 +
 .../jet/lang/resolve/BindingTraceContext.java |  5 ++
 4 files changed, 63 insertions(+)

diff --git a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
index 6c058df6985..93c08b04226 100644
--- a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
+++ b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
@@ -164,6 +164,55 @@ public class ExpressionCodegen extends JetVisitor {
         myLoopStarts.pop();
     }
 
+    @Override
+    public void visitForExpression(JetForExpression expression) {
+        final JetExpression loopRange = expression.getLoopRange();
+        final JetParameter parameter = expression.getLoopParameter();
+        final DeclarationDescriptor descriptor = bindingContext.getParameterDescriptor(parameter);
+        Type loopRangeType = expressionType(loopRange);
+        if (loopRangeType.getSort() == Type.ARRAY) {
+            generateForInArray(expression, descriptor, loopRangeType);
+        }
+        else {
+            throw new UnsupportedOperationException("for/in loop currently only supported for arrays");
+        }
+    }
+
+    private void generateForInArray(JetForExpression expression, DeclarationDescriptor descriptor, Type loopRangeType) {
+        JetType paramType = bindingContext.getExpressionType(expression.getLoopParameter());
+        Type asmParamType = typeMapper.mapType(paramType);
+
+        int indexVar = myMap.enterTemp();
+        v.aconst(0);
+        v.store(indexVar, Type.INT_TYPE);
+        int paramVar = myMap.getIndex(descriptor);
+
+        Label condition = new Label();
+        Label end = new Label();
+        v.mark(condition);
+        myLoopStarts.push(condition);
+
+        v.load(indexVar, Type.INT_TYPE);
+        gen(expression.getLoopRange(), loopRangeType);  // index array
+        v.dup2();                                       // index array index array
+        v.arraylength();                                // index array index array.length
+        v.ifge(end);                                    // index array
+        v.swap();                                       // array index
+        v.aload(loopRangeType.getElementType());
+        StackValue.onStack(loopRangeType.getElementType()).put(asmParamType, v);
+        v.store(paramVar, asmParamType);
+
+        gen(expression.getBody(), Type.VOID_TYPE);
+
+        v.goTo(condition);
+
+        myLoopEnds.push(end);
+
+        myMap.leave(descriptor);
+//        TODO v.visitLocalVariable(parameter.getName(), );
+        myMap.leaveTemp();
+    }
+
     @Override
     public void visitBreakExpression(JetBreakExpression expression) {
         JetSimpleNameExpression labelElement = expression.getTargetLabel();
diff --git a/idea/src/org/jetbrains/jet/codegen/FrameMap.java b/idea/src/org/jetbrains/jet/codegen/FrameMap.java
index 5060ff56b0d..98b46f592ca 100644
--- a/idea/src/org/jetbrains/jet/codegen/FrameMap.java
+++ b/idea/src/org/jetbrains/jet/codegen/FrameMap.java
@@ -24,6 +24,14 @@ public class FrameMap {
         return myVarIndex.remove(descriptor);
     }
 
+    public int enterTemp() {
+        return myMaxIndex++;
+    }
+
+    public void leaveTemp() {
+        myMaxIndex--;
+    }
+
     public int getIndex(DeclarationDescriptor descriptor) {
         return myVarIndex.contains(descriptor) ? myVarIndex.get(descriptor) : -1;
     }
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/BindingContext.java b/idea/src/org/jetbrains/jet/lang/resolve/BindingContext.java
index ee530abe7d6..6068f32d4b4 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/BindingContext.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/BindingContext.java
@@ -13,6 +13,7 @@ public interface BindingContext {
     TypeParameterDescriptor getTypeParameterDescriptor(JetTypeParameter declaration);
     FunctionDescriptor getFunctionDescriptor(JetFunction declaration);
     PropertyDescriptor getPropertyDescriptor(JetProperty declaration);
+    DeclarationDescriptor getParameterDescriptor(JetParameter declaration);
 
     JetType getExpressionType(JetExpression expression);
 
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java b/idea/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java
index 26bcdc43135..05c5ceefc19 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java
@@ -111,6 +111,11 @@ public class BindingTraceContext extends BindingTrace implements BindingContext
         return (PropertyDescriptor) declarationsToDescriptors.get(declaration);
     }
 
+    @Override
+    public DeclarationDescriptor getParameterDescriptor(JetParameter declaration) {
+        return declarationsToDescriptors.get(declaration);
+    }
+
     @Override
     public JetType resolveTypeReference(JetTypeReference typeReference) {
         return types.get(typeReference);