Optimize int.parse with a radix.

runtime/lib/string_patch.dart

Index: runtime/lib/string_patch.dart
diff --git a/runtime/lib/string_patch.dart b/runtime/lib/string_patch.dart
index 9a454b114da22988e9e3ccbb692b605011f8ea72..deb5fcf161410224d29ca5ef2cfc6d68399fc668 100644
--- a/runtime/lib/string_patch.dart
+++ b/runtime/lib/string_patch.dart
@@ -260,12 +260,13 @@ class _StringBase {
       native "StringBase_substringUnchecked";
 
   // Checks for one-byte whitespaces only.
-  static bool _isOneByteWhitespace(int codePoint) {
-    return
-      (codePoint == 32) || // Space.
-      ((codePoint <= 13) ? (9 <= codePoint)  // CR, LF, TAB, etc.
-                         : ((codePoint == 0x85) ||  // NEL
-                            (codePoint == 0xA0)));  // NBSP
+  static bool _isOneByteWhitespace(int codeUnit) {
+    if (codeUnit <= 32) {
+      return ((codeUnit == 32) || // Space.
+              ((codeUnit <= 13) && (codeUnit >= 9)));  // CR, LF, TAB, etc.
+    }
+    if (codeUnit < 0x85) return false;
+    return (codeUnit == 0x85) || (codeUnit == 0xA0);

[Lasse Reichstein Nielsen, 2014/09/23 11:34:45]

Restructured to return false quickly on most ASCII chars (range 0x21..0x7f).

   }
 
   // Characters with Whitespace property (Unicode 6.2).
@@ -284,7 +285,12 @@ class _StringBase {
   //
   // BOM: 0xFEFF
   static bool _isTwoByteWhitespace(int codeUnit) {
-    if (codeUnit <= 0xA0) return _isOneByteWhitespace(codeUnit);
+    if (codeUnit <= 32) {
+      return (codeUnit == 32) ||
+             ((codeUnit <= 13) && (codeUnit >= 9));
+    }
+    if (codeUnit < 0x85) return false;
+    if ((codeUnit == 0x85) || (codeUnit == 0xA0)) return true;
     return (codeUnit <= 0x200A)
             ? ((codeUnit == 0x1680) ||
                (codeUnit == 0x180E) ||