Add num.parse.

runtime/lib/double_patch.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.
 // Dart core library.
 
 // VM implementation of double.
 
 patch class double {
 
   static double _native_parse(_OneByteString string) native "Double_parse";
@@ skipping 27 matching lines @@
     return _native_parse(oneByteString);
   }
 
   /* patch */ static double parse(String str,
                                   [double onError(String str)]) {
     var result = _parse(str);
     if (result == null) {
       if (onError == null) throw new FormatException(str);
       return onError(str);
     }
+    // Parse can create a NaN that is not identical to double.NAN.
+    if (result.isNaN) return NAN;

[Lasse Reichstein Nielsen, 2013/11/25 12:37:40]

This seems like an unnecessary hack.

The NaNs should be considered equal by Instance::IsIdenticalTo, which is what
the native Identical_comparison uses. Apparently something else happens instead.

[floitsch, 2013/11/25 12:50:53]

completely agree.
Please file a bug for the VM so that this can't happen for other NANs.

     return result;
   }
 }