Improve ScanJsonNumber.

src/scanner.h

 // Copyright 2010 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
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 130 matching lines @@
 
 class JsonScanner : public Scanner {
  public:
   JsonScanner();
 
   void Initialize(UC16CharacterStream* source);
 
   // Returns the next token.
   Token::Value Next();
 
+  // Returns the value of a number token.
+  double number() {

[tfarina, 2011/02/04 15:04:44]

I'll not insist in the const here, but I'd like to know if you tried compiling
with it and it didn't work. Also, I'll not insist in putting everything at the
same line. But it fits and it's very common practice on V8 code.

[Lasse Reichstein, 2011/02/07 08:40:43]

We generally don't use const in the V8 code.
It should work, and probably wouldn't hurt if added, but it's only necessary if
you ever have a const reference to the scanner, and we probably won't have that
either.

As for making it a one-liner ... I wouldn't insist either way either. I prefer
the three-line code, but I can understand the argument for having more
meaningful lines on screen at a atime.

+    return number_;
+  }
+
+
  protected:
   // Skip past JSON whitespace (only space, tab, newline and carrige-return).
   bool SkipJsonWhiteSpace();
 
   // Scan a single JSON token. The JSON lexical grammar is specified in the
   // ECMAScript 5 standard, section 15.12.1.1.
   // Recognizes all of the single-character tokens directly, or calls a function
   // to scan a number, string or identifier literal.
   // The only allowed whitespace characters between tokens are tab,
   // carriage-return, newline and space.
@@ skipping 10 matching lines @@
   // A JSON string (production JSONString) is subset of valid JavaScript string
   // literals. The string must only be double-quoted (not single-quoted), and
   // the only allowed backslash-escapes are ", /, \, b, f, n, r, t and
   // four-digit hex escapes (uXXXX). Any other use of backslashes is invalid.
   Token::Value ScanJsonString();
 
   // Used to recognizes one of the literals "true", "false", or "null". These
   // are the only valid JSON identifiers (productions JSONBooleanLiteral,
   // JSONNullLiteral).
   Token::Value ScanJsonIdentifier(const char* text, Token::Value token);
+
+  // Holds the value of a scanned number token.
+  double number_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCANNER_H_