Implement cascaded calls.

lib/compiler/implementation/typechecker.dart

 // Copyright (c) 2012, 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.
 
 class TypeCheckerTask extends CompilerTask {
   TypeCheckerTask(Compiler compiler) : super(compiler);
   String get name() => "Type checker";
 
   static final bool LOG_FAILURES = false;
 
@@ skipping 160 matching lines @@
 
 class TypeCheckerVisitor implements Visitor<Type> {
   final Compiler compiler;
   final TreeElements elements;
   Node lastSeenNode;
   final Types types;
 
   Type expectedReturnType;
   ClassElement currentClass;
 
+  Link<Type> cascadeTypes = const EmptyLink<Type>();
+
   Type intType;
   Type doubleType;
   Type boolType;
   Type stringType;
   Type objectType;
   Type listType;
 
   TypeCheckerVisitor(Compiler this.compiler, TreeElements this.elements,
                      Types this.types) {
     intType = lookupType(Types.INT, compiler, types);
@@ skipping 54 matching lines @@
   checkAssignable(Node node, Type s, Type t) {
     if (!types.isAssignable(s, t)) {
       reportTypeWarning(node, MessageKind.NOT_ASSIGNABLE, [s, t]);
     }
   }
 
   checkCondition(Expression condition) {
     checkAssignable(condition, boolType, analyze(condition));
   }
 
+  void pushCascadeType(Type type) {
+    cascadeTypes = cascadeTypes.prepend(type);
+  }
+
+  void popCascadeType() {
+    Type type = cascadeTypes.head;
+    cascadeTypes = cascadeTypes.tail;
+    return type;
+  }
+
   Type visitBlock(Block node) {
     return analyze(node.statements);
   }
 
+  Type visitCascade(Cascade node) {
+    analyze(node.expression);
+    return popCascadeType();
+  }
+
+  Type visitCascadeReceiver(CascadeReceiver node) {
+    Type type = analyze(node.expression);
+    pushCascadeType(type);
+    return type;
+  }
+
   Type visitClassNode(ClassNode node) {
     fail(node);
   }
 
   Type visitDoWhile(DoWhile node) {
     StatementType bodyType = analyze(node.body);
     checkCondition(node.condition);
     return bodyType.join(StatementType.NOT_RETURNING);
   }
 
@@ skipping 438 matching lines @@
   }
 
   visitCatchBlock(CatchBlock node) {
     fail(node);
   }
 
   visitTypedef(Typedef node) {
     fail(node);
   }
 }