Generative constructors in the new dart backend.

pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.dart

 // Copyright (c) 2014, 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 dart_tree_printer;
 
 import '../constants/values.dart' as values;
 import '../dart_types.dart' as types;
 import '../dart2jslib.dart' as dart2js;
 import '../elements/elements.dart' as elements;
@@ skipping 324 matching lines @@
             [makeExpression(left.index), makeExpression(exp.right)]);
       } else {
         throw "Unexpected left-hand side of assignment: ${left}";
       }
       tree.Operator op = new tree.Operator(assignmentToken(exp.operator));
       result = new tree.SendSet(receiver, selector, op, arguments);
       if (left is Identifier) {
         setElement(result, element, exp);
       }
       precedence = EXPRESSION;
+    } else if (exp is FieldInitializer) {
+      precedence = EXPRESSION;
+      tree.Node receiver = makeIdentifier('this');
+      tree.Node selector = makeIdentifier(exp.element.name);
+      tree.Operator op = new tree.Operator(assignmentToken("="));
+      // We pass CALLEE to ensure we write eg.:
+      // class B { var x; B() : x = (() {return a;}) {}}
+      // Not the invalid:
+      // class B { var x; B() : x = () {return a;} {}}
+      result = new tree.SendSet(receiver, selector, op,
+                                singleton(makeExp(exp.body, CALLEE)));
+      setElement(result, exp.element, exp);
+    } else if (exp is SuperInitializer) {
+      precedence = EXPRESSION;
+      tree.Node receiver = makeIdentifier('super');
+      tree.NodeList arguments =
+          argList(exp.arguments.map(makeArgument).toList());
+      if (exp.target.name == "") {
+        result = new tree.Send(null, receiver, arguments);
+      } else {
+        result = new tree.Send(receiver,
+                               makeIdentifier(exp.target.name),
+                               arguments);
+      }
+      setElement(result, exp.target, exp);
     } else if (exp is BinaryOperator) {
       precedence = BINARY_PRECEDENCE[exp.operator];
       int deltaLeft = isAssociativeBinaryOperator(precedence) ? 0 : 1;
       result = new tree.Send(
           makeExp(exp.left, precedence + deltaLeft, beginStmt: beginStmt),
           new tree.Operator(binopToken(exp.operator)),
           singleton(makeExp(exp.right, precedence + 1)));
     } else if (exp is CallFunction) {
       precedence = CALLEE;
       tree.Node selector;
@@ skipping 60 matching lines @@
           makeExp(exp.thenExpression, EXPRESSION),
           makeExp(exp.elseExpression, EXPRESSION),
           question,
           colon);
     } else if (exp is FieldExpression) {
       precedence = PRIMARY;
       tree.Node receiver = exp.object is This
           ? null
           : makeExp(exp.object, PRIMARY, beginStmt: beginStmt);
       result = new tree.Send(receiver, makeIdentifier(exp.fieldName));
+    } else if (exp is ConstructorDefinition) {
+      precedence = EXPRESSION;
+      tree.NodeList parameters = makeParameters(exp.parameters);
+      tree.NodeList initializers =
+          exp.initializers == null || exp.initializers.isEmpty
+          ? null
+          : makeList(",", exp.initializers.map(makeExpression).toList());
+      tree.Node body = exp.isConst || exp.body == null
+          ? new tree.EmptyStatement(semicolon)
+          : makeFunctionBody(exp.body);
+      result = new tree.FunctionExpression(constructorName(exp),
+          parameters,
+          body,
+          null,  // return type
+          makeFunctionModifiers(exp),
+          initializers,
+          null,  // get/set
+          null); // async modifier
     } else if (exp is FunctionExpression) {
       precedence = PRIMARY;
       if (beginStmt && exp.name != null) {
         needParen = true; // Do not mistake for function declaration.
       }
       Token getOrSet = exp.isGetter
           ? getToken
           : exp.isSetter
               ? setToken
               : null;
@@ skipping 566 matching lines @@
     return makeModifiers(isStatic: isStatic,
                          isConst: isConst,
                          isFinal: isFinal,
                          isVar: useVar && !(isConst || isFinal));
   }
 
   tree.Modifiers makeFunctionModifiers(FunctionExpression exp) {
     if (exp.element == null) return makeEmptyModifiers();
     return makeModifiers(isExternal: exp.element.isExternal,
                          isStatic: exp.element.isStatic,
-                         isFactory: exp.element.isFactoryConstructor);
+                         isFactory: exp.element.isFactoryConstructor,
+                         isConst: exp.element.isConst);
   }
 
   tree.Node makeNodeForClassElement(elements.ClassElement cls) {
     if (cls.isMixinApplication) {
       return makeNamedMixinApplication(cls);
     } else {
       return makeClassNode(cls);
     }
   }
 
@@ skipping 132 matching lines @@
         cls.interfaces, mixinTypes);
 
     Token extendsKeyword = supernode != null ? extendsToken : null;
     return new tree.ClassNode(
         modifiers, name, typeParameters, supernode,
         interfaces, openBrace, extendsKeyword,
         null, // No body.
         closeBrace);
   }
 
+  tree.Node constructorName(ConstructorDefinition exp) {
+    String name = exp.name;
+    tree.Identifier className = makeIdentifier(exp.element.enclosingClass.name);
+    tree.Node result = name == ""
+        ? className
+        : new tree.Send(className, makeIdentifier(name));
+    setElement(result, exp.element, exp);
+    return result;
+  }
+
   tree.Node functionName(FunctionExpression exp) {
     String name = exp.name;
     if (name == null) return null;
     if (isUserDefinableOperator(name)) {
       return makeOperator("operator$name");
     } else if (name == "unary-") {
       return makeOperator("operator-");
     }
     return makeIdentifier(name);
   }
@@ skipping 70 matching lines @@
             printStringChunk(chunk.previous),
             node);
       } else {
         return node;
       }
     }
     return printStringChunk(output.chunk);
   }
 
 }