Rewrite double.parse.

sdk/lib/core/double.dart

Index: sdk/lib/core/double.dart
diff --git a/sdk/lib/core/double.dart b/sdk/lib/core/double.dart
index 65b9c3096ed87dacce8d40d51f29c4892a466eca..781b9d5dc1dfec1a0fdc48f5ffeb6ba89dcc4406 100644
--- a/sdk/lib/core/double.dart
+++ b/sdk/lib/core/double.dart
@@ -133,16 +133,33 @@ abstract class double extends num {
   /**
    * Parse [source] as an double literal and return its value.
    *
-   * Accepts the same format as double literals:
-   *   [: ['+'|'-'] [digit* '.'] digit+ [('e'|'E') ['+'|'-'] digit+] :]
+   * Accepts the following format:
+   * `/^\s*[+-]?(?:Infinity|NaN|(?:\.\d+|\d+(?:\.\d*)?)(?:[eE][+-]?\d+)?)\s*$`.
    *
-   * Also recognizes "NaN", "Infinity" and "-Infinity" as inputs and
-   * returns the corresponding double value.
+   * In English this equals an optional sign followed by either, "Infinity",
+   * "NaN" or a double number. A double number is composed of the mantissa and
+   * and optional exponent part. The mantissa is either a dot followed by a
+   * sequence of digits, or a sequence of digits optionally followed by a dot
+   * and more digits. The (optional) exponent part consists of the character
+   * "e" or "E", an optional sign, and the exponent digits.
    *
-   * If the [soure] is not a valid double literal, the [handleError]
+   * The whole double may be surrounded by whitespace.
+   *
+   * If the [source] is not a valid double literal, the [handleError]
    * is called with the [source] as argument, and its return value is
    * used instead. If no handleError is provided, a [FormatException]
    * is thrown.
+   *
+   * Examples of accepted strings:
+   *
+   *     "3.14"
+   *     "  3.14 \xA0"
+   *     "0."
+   *     ".0"
+   *     "-1.e3"
+   *     "1234E+7"
+   *     "+.12e-9"
+   *     "-NaN"
    */
   external static double parse(String source,
                                [double handleError(String source)]);