make DateParser::TimeComposer handle milliseconds properly...

src/dateparser.h

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
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 //       disclaimer in the documentation and/or other materials provided
@@ skipping 69 matching lines @@
     // Read a string of digits as an unsigned number (cap just below kMaxInt).
     int ReadUnsignedNumber() {
       has_read_number_ = true;
       int n;
       for (n = 0; IsAsciiDigit() && n < kMaxInt / 10 - 1; Next()) {
         n = n * 10 + ch_ - '0';
       }
       return n;
     }
 
+    // Read a string of digits as an unsigned number of milliseconds (cap just
+    // below kMaxInt).
+    int ReadMilliseconds() {

[Lasse Reichstein, 2010/11/25 10:17:19]

Seems like overkill (and potentially fragile) to read and parse all those
digits, and then throwing them away by dividing.

How about just reading the first up-to-three digits and collect them in a
result. Then, if reading less than three, multiply it by ten until it's properly
aligned (so .5 becomes 500). Then skip any following digits.
This avoids having to check against kMaxInt, and doesn't limit the number of
digits arbitrarily.

+      has_read_number_ = true;
+      int n;
+      int i = 0;
+      for (n = 0; IsAsciiDigit() && n < kMaxInt / 10 - 1 && i < 3; Next()) {
+        n = n * 10 + ch_ - '0';
+        i++;
+      }
+      return n * pow(10, 3 - i);
+    }
+
     // Read a word (sequence of chars. >= 'A'), fill the given buffer with a
     // lower-case prefix, and pad any remainder of the buffer with zeroes.
     // Return word length.
     int ReadWord(uint32_t* prefix, int prefix_size) {
       int len;
       for (len = 0; IsAsciiAlphaOrAbove(); Next(), len++) {
         if (len < prefix_size) prefix[len] = AsciiAlphaToLower(ch_);
       }
       for (int i = len; i < prefix_size; i++) prefix[i] = 0;
       return len;
@@ skipping 142 matching lines @@
     int comp_[kSize];
     int index_;
     int named_month_;
   };
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_DATEPARSER_H_