runtime/LiteralParser.h

   1 /*
   2  * Copyright (C) 2009 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef LiteralParser_h
  27 #define LiteralParser_h
  28
  29 #include "JSGlobalObjectFunctions.h"
  30 #include "JSValue.h"
  31 #include "UString.h"
  32
  33 namespace JSC {
  34
  35     class LiteralParser {
  36     public:
  37         typedef enum { StrictJSON, NonStrictJSON } ParserMode;
  38         LiteralParser(ExecState* exec, const UString& s, ParserMode mode)
  39             : m_exec(exec)
  40             , m_lexer(s, mode)
  41             , m_mode(mode)
  42         {
  43         }
  44
  45         JSValue tryLiteralParse()
  46         {
  47             m_lexer.next();
  48             JSValue result = parse(m_mode == StrictJSON ? StartParseExpression : StartParseStatement);
  49             if (m_lexer.currentToken().type != TokEnd)
  50                 return JSValue();
  51             return result;
  52         }
  53     private:
  54         enum ParserState { StartParseObject, StartParseArray, StartParseExpression,
  55                            StartParseStatement, StartParseStatementEndStatement,
  56                            DoParseObjectStartExpression, DoParseObjectEndExpression,
  57                            DoParseArrayStartExpression, DoParseArrayEndExpression };
  58         enum TokenType { TokLBracket, TokRBracket, TokLBrace, TokRBrace,
  59                          TokString, TokIdentifier, TokNumber, TokColon,
  60                          TokLParen, TokRParen, TokComma, TokTrue, TokFalse,
  61                          TokNull, TokEnd, TokError };
  62
  63         class Lexer {
  64         public:
  65             struct LiteralParserToken {
  66                 TokenType type;
  67                 const UChar* start;
  68                 const UChar* end;
  69                 UString stringToken;
  70                 double numberToken;
  71             };
  72             Lexer(const UString& s, ParserMode mode)
  73                 : m_string(s)
  74                 , m_mode(mode)
  75                 , m_ptr(s.data())
  76                 , m_end(s.data() + s.size())
  77             {
  78             }
  79
  80             TokenType next()
  81             {
  82                 return lex(m_currentToken);
  83             }
  84
  85             const LiteralParserToken& currentToken()
  86             {
  87                 return m_currentToken;
  88             }
  89
  90         private:
  91             TokenType lex(LiteralParserToken&);
  92             template <ParserMode mode> TokenType lexString(LiteralParserToken&);
  93             TokenType lexNumber(LiteralParserToken&);
  94             LiteralParserToken m_currentToken;
  95             UString m_string;
  96             ParserMode m_mode;
  97             const UChar* m_ptr;
  98             const UChar* m_end;
  99         };
 100
 101         class StackGuard;
 102         JSValue parse(ParserState);
 103
 104         ExecState* m_exec;
 105         LiteralParser::Lexer m_lexer;
 106         ParserMode m_mode;
 107     };
 108 }
 109
 110 #endif