Tag closures with their types

lib/src/js/printer.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.
 
 part of js_ast;
 
 
 class JavaScriptPrintingOptions {
   final bool shouldCompressOutput;
   final bool minifyLocalVariables;
@@ skipping 843 matching lines @@
     } else {
       out("(");
       visitCommaSeparated(fun.params, PRIMARY,
           newInForInit: false, newAtStatementBegin: false);
       out(")");
     }
     spaceOut();
     out("=>");
     if (fun.body is Expression) {
       spaceOut();
+      // Object initializers require parenthesis to disambiguate
+      // AssignmentExpression from FunctionBody. See:
+      // https://people.mozilla.org/~jorendorff/es6-draft.html#sec-arrow-function-defi...

[Jennifer Messerly, 2015/05/19 22:49:48]

`sec-arrow-function-definitions` seems to have gotten cut off

[Leaf, 2015/05/19 23:24:07]

Done.

+      var needsParen = fun.body is ObjectInitializer;
+      if (needsParen) out("(");
       visitNestedExpression(fun.body, ASSIGNMENT,
           newInForInit: false, newAtStatementBegin: false);
+      if (needsParen) out(")");
     } else {
       blockBody(fun.body, needsSeparation: false, needsNewline: false);
     }
     localNamer.leaveScope();
     if (fun.bindThisWorkaround) {
       out(").bind(this)");
     }
   }
 
   visitLiteralBool(LiteralBool node) {
@@ skipping 37 matching lines @@
       if (i != elements.length - 1) out(",");
     }
     out("]");
   }
 
   visitArrayHole(ArrayHole node) {
     throw "Unreachable";
   }
 
   visitObjectInitializer(ObjectInitializer node) {
-    // Print all the properties on one line until we see a function-valued
-    // property.  Ideally, we would use a proper pretty-printer to make the
-    // decision based on layout.
     List<Property> properties = node.properties;
     out("{");
     indentMore();
 
-    var isOneLiner = !properties.any((p) => p.value is FunctionExpression);
+    var isOneLiner = !node.vertical;
     for (int i = 0; i < properties.length; i++) {
       if (i != 0) {
         out(",");
         if (isOneLiner) spaceOut();
       }
       if (!isOneLiner) {
         forceLine();
         indent();
       }
       visit(properties[i]);
@@ skipping 493 matching lines @@
     declare(node.name);
     node.function.accept(this);
   }
 
   visitClassExpression(ClassExpression node) {
     declare(node.name);
     if (node.heritage != null) node.heritage.accept(this);
     for (Method element in node.methods) element.accept(this);
   }
 }