Implement type checking of map literals (issue 221).

runtime/lib/literal_map_factory.dart

Index: runtime/lib/literal_map_factory.dart
===================================================================
--- runtime/lib/literal_map_factory.dart	(revision 0)
+++ runtime/lib/literal_map_factory.dart	(revision 0)
@@ -0,0 +1,26 @@
+// Copyright (c) 2011, 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.
+// Immutable map class for compiler generated map literals.
+
+class _LiteralMapFactory {
+  // [elements] contains n key-value pairs. The keys are at position
+  // 2*n, the values at position 2*n+1.
+  factory Map<K, V>.fromLiteral(int location,
+                                String value_type,
+                                List elements) {
+    var map = new LinkedHashMap<String, V>();
+    var len = elements.length;
+    for (int i = 1; i < len; i += 2) {
+      // The type of the key has been checked in the parser already.
+      if (elements[i] is !V) {
+        TypeError._throwNew(location,
+                            elements[i],
+                            value_type,
+                            "map literal value at index ${i ~/ 2}");
+      }
+      map[elements[i-1]] = elements[i];

[srdjan, 2011/11/23 03:43:44]

space between -> 'i - 1'

[regis, 2011/11/23 15:51:32]

Will do.

+    }
+    return map;
+  }
+}