Implement Function.apply in dart2js.

tests/corelib/apply2_test.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.
-//
-// This test should move to a language test once the apply method
-// gets into the specification.
 
 apply(Function function, ArgumentDescriptor args) {
-  int argumentCount = 0;
-  StringBuffer buffer = new StringBuffer();
-  List arguments = [];
-
-  if (args.positionalArguments != null) {
-    argumentCount += args.positionalArguments.length;
-    arguments.addAll(args.positionalArguments);
-  }
-
-  // Sort the named arguments to get the right selector name and
-  // arguments order.
-  if (args.namedArguments != null && !args.namedArguments.isEmpty()) {
-    // Call new List.from to make sure we get a JavaScript array.
-    List<String> namedArguments =
-        new List<String>.from(args.namedArguments.getKeys());
-    argumentCount += namedArguments.length;
-    // We're sorting on strings, and the behavior is the same between
-    // Dart string sort and JS String sort. To avoid needing the Dart
-    // sort implementation, we use the JavaScript one instead.
-    JS('void', '#.sort()', namedArguments);
-    namedArguments.forEach((String name) {
-      buffer.add('\$$name');
-      arguments.add(args.namedArguments[name]);
-    });
-  }
-
-  String selectorName = 'call\$$argumentCount$buffer';
-  var jsFunction = JS('var', '#[#]', function, selectorName);
-  if (jsFunction == null) {
-    throw new NoSuchMethodError(function, selectorName, arguments);
-  }
-  // We bound 'this' to [function] because of how we compile
-  // closures: escaped local variables are stored and accessed through
-  // [function].
-  return JS('var', '#.apply(#, #)', jsFunction, function, arguments);
+  return Function.apply(
+      function, args.positionalArguments, args.namedArguments);
 }
 
 class ArgumentDescriptor {
   final List positionalArguments;
   final Map<String, Dynamic> namedArguments;
 
   ArgumentDescriptor(this.positionalArguments, this.namedArguments);
 }
 
 void throwsNSME(function) {
   Expect.throws(function, (e) => e is NoSuchMethodError);
 }
 
 main() {
   var c1 = () => 'c1';
   var c2 = (a) => 'c2 $a';
   var c3 = ([a = 1]) => 'c3 $a';
   var c4 = ({a: 1}) => 'c4 $a';
   var c5 = ({a: 1, b: 2}) => 'c5 $a $b';
   var c6 = ({b: 1, a: 2}) => 'c6 $a $b';
 
-  // TODO(ngeoffray): Remove these calls. They are currently needed
-  // because otherwise we would not generate the stubs. Once apply is
-  // in the specification, we should change the compiler to emit stubs
-  // for closures once it sees an 'apply' selector.
-  c1();
-  c2(1);
-  c3(); c3(1);
-  c4(); c4(a: 1);
-  c5(); c5(a: 1); c5(b: 2); c5(a:1, b: 2);
-  c6(); c6(a: 1); c6(b: 2); c6(a:1, b: 2);
-
   Expect.equals('c1', apply(c1, new ArgumentDescriptor(null, null)));
   Expect.equals('c1', apply(c1, new ArgumentDescriptor([], null)));
   Expect.equals('c1', apply(c1, new ArgumentDescriptor([], {})));
   Expect.equals('c1', apply(c1, new ArgumentDescriptor(null, {})));
   throwsNSME(() => apply(c1, new ArgumentDescriptor([1], null)));
   throwsNSME(() => apply(c1, new ArgumentDescriptor([1], {'a': 2})));
   throwsNSME(() => apply(c1, new ArgumentDescriptor(null, {'a': 2})));
 
   Expect.equals('c2 1', apply(c2, new ArgumentDescriptor([1], null)));
   Expect.equals('c2 1', apply(c2, new ArgumentDescriptor([1], {})));
   throwsNSME(() => apply(c2, new ArgumentDescriptor(null, null)));
   throwsNSME(() => apply(c2, new ArgumentDescriptor([], null)));
   throwsNSME(() => apply(c2, new ArgumentDescriptor(null, {})));
   throwsNSME(() => apply(c2, new ArgumentDescriptor(null, {'a': 1})));
 
   Expect.equals('c3 1', apply(c3, new ArgumentDescriptor([], null)));
   Expect.equals('c3 2', apply(c3, new ArgumentDescriptor([2], {})));
   throwsNSME(() => apply(c3, new ArgumentDescriptor([1, 2], null)));
-  // TODO(ngeoffray): Should be throwsNSME with the new parameter
-  // specification.
-  Expect.equals('c3 1', apply(c3, new ArgumentDescriptor(null, {'a': 1})));
+  throwsNSME(() => apply(c3, new ArgumentDescriptor(null, {'a': 1})));
 
   Expect.equals('c4 1', apply(c4, new ArgumentDescriptor([], null)));
   Expect.equals('c4 2', apply(c4, new ArgumentDescriptor([], {'a': 2})));
   Expect.equals('c4 1', apply(c4, new ArgumentDescriptor(null, null)));
   Expect.equals('c4 1', apply(c4, new ArgumentDescriptor([], {})));
   throwsNSME(() => apply(c4, new ArgumentDescriptor([1], {'a': 1})));
   throwsNSME(() => apply(c4, new ArgumentDescriptor([1], {})));
   throwsNSME(() => apply(c4, new ArgumentDescriptor([], {'a': 1, 'b': 2})));
 
   Expect.equals('c5 1 2', apply(c5, new ArgumentDescriptor([], null)));
@@ skipping 19 matching lines @@
       apply(c6, new ArgumentDescriptor([], {'a': 3, 'b': 4})));
   Expect.equals('c6 4 3',
       apply(c6, new ArgumentDescriptor([], {'b': 3, 'a': 4})));
   Expect.equals('c6 2 3',
       apply(c6, new ArgumentDescriptor([], {'b': 3})));
   throwsNSME(() => apply(c6, new ArgumentDescriptor([1], {'a': 1})));
   throwsNSME(() => apply(c6, new ArgumentDescriptor([1], {})));
   throwsNSME(() =>
       apply(c6, new ArgumentDescriptor([], {'a': 1, 'b': 2, 'c': 3})));
 }