Handle for-in loops

lib/src/checker/checker.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dev_compiler.src.checker.checker;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/scanner.dart' show Token, TokenType;
@@ skipping 393 matching lines @@
   }
 
   @override
   visitConstructorFieldInitializer(ConstructorFieldInitializer node) {
     var field = node.fieldName;
     DartType staticType = _rules.elementType(field.staticElement);
     node.expression = checkAssignment(node.expression, staticType);
     node.visitChildren(this);
   }
 
+  @override
+  visitForEachStatement(ForEachStatement node) {
+    // Check that the expression is an Iterable.
+    var expr = node.iterable;
+    var iterableType = _rules.provider.iterableType;
+    var loopVariable = node.identifier != null
+        ? node.identifier
+        : node.loopVariable.identifier;
+    var iteratorType = loopVariable.staticType;
+    var checkedType = iterableType.substitute4([iteratorType]);
+    node.iterable = checkAssignment(expr, checkedType);
+    node.visitChildren(this);
+  }
+
   @override visitListLiteral(ListLiteral node) {
     var type = _rules.provider.dynamicType;
     if (node.typeArguments != null) {
       var targs = node.typeArguments.arguments;
       if (targs.length > 0) type = targs[0].type;
     }
     var elements = node.elements;
     for (int i = 0; i < elements.length; i++) {
       elements[i] = checkArgument(elements[i], type);
     }
@@ skipping 354 matching lines @@
   void _recordDynamicInvoke(AstNode node) {
     _reporter.log(new DynamicInvoke(_rules, node));
   }
 
   void _recordMessage(StaticInfo info) {
     if (info == null) return;
     if (info.level >= logger.Level.SEVERE) _failure = true;
     _reporter.log(info);
   }
 }