Some fixes to Math.pow.

runtime/lib/double.dart

 // 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.
 
 class Double implements double {
   factory Double.fromInteger(int value)
       native "Double_doubleFromInteger";
   int hashCode() {
     try {
       return toInt();
@@ skipping 94 matching lines @@
   }
 
   double round() native "Double_round";
   double floor() native "Double_floor";
   double ceil () native "Double_ceil";
   double truncate() native "Double_truncate";
   int toInt() native "Double_toInt";
   double toDouble() { return this; }
 
   double pow(num exponent) {
-    return _pow(exponent.toDouble());
+    if (exponent == 0) {
+      return 1.0;  // ECMA-262 15.8.2.13

[ngeoffray, 2012/03/02 07:55:47]

Wouldn't it be better to point to Dart spec instead? and the Dart spec listing
all these cases (even if the text explaining is missing).

[srdjan, 2012/03/02 17:55:37]

Good point. There is no Dart library spec for "pow" yet and I will file a
request for it. The comment says that the implementation does implement what
ECMA-262 says. I think it is helpful in the way that it does not seem
arbitrarily.
 

+    }
+    // Throw NullPointerException if exponent is null.
+    double doubleExponent = exponent.toDouble();
+    if (isNaN() || exponent.isNaN()) {
+      return double.NAN;
+    }
+    return _pow(doubleExponent);
   }
   double _pow(double exponent) native "Double_pow";
 
   String toStringAsFixed(int fractionDigits) {
     // See ECMAScript-262, 15.7.4.5 for details.
 
     // Step 2.
     if (fractionDigits < 0 || fractionDigits > 20) {
       // TODO(antonm): should be proper RangeError or Dart counterpart.
       throw "Range error";
@@ skipping 88 matching lines @@
         return EQUAL;
       }
     } else if (isNaN()) {
       return other.isNaN() ? EQUAL : GREATER;
     } else {
       // Other is NaN.
       return LESS;
     }
   }
 }