зеркало из https://github.com/mozilla/gecko-dev.git
105 строки
4.1 KiB
C++
105 строки
4.1 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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*
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* The contents of this file are subject to the Netscape Public
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* License Version 1.1 (the "License"); you may not use this file
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* except in compliance with the License. You may obtain a copy of
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* the License at http://www.mozilla.org/NPL/
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*
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* Software distributed under the License is distributed on an "AS
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* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express oqr
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* implied. See the License for the specific language governing
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* rights and limitations under the License.
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*
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* The Original Code is the JavaScript 2 Prototype.
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*
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* The Initial Developer of the Original Code is Netscape
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* Communications Corporation. Portions created by Netscape are
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* Copyright (C) 1998 Netscape Communications Corporation. All
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* Rights Reserved.
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*
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* Contributor(s):
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*
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* Alternatively, the contents of this file may be used under the
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* terms of the GNU Public License (the "GPL"), in which case the
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* provisions of the GPL are applicable instead of those above.
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* If you wish to allow use of your version of this file only
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* under the terms of the GPL and not to allow others to use your
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* version of this file under the NPL, indicate your decision by
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* deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL. If you do not delete
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* the provisions above, a recipient may use your version of this
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* file under either the NPL or the GPL.
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*/
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#ifndef lexer_h___
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#define lexer_h___
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#include "utilities.h"
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#include "formatter.h"
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#include "reader.h"
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#include "token.h"
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#include "world.h"
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namespace JavaScript
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{
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class Lexer {
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enum {tokenLookahead = 2}; // Number of tokens that can be simultaneously live
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#ifdef DEBUG
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enum {tokenGuard = 10}; // Number of invalid tokens added to circular token buffer to catch references to old tokens
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#else
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enum {tokenGuard = 0}; // Number of invalid tokens added to circular token buffer to catch references to old tokens
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#endif
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// Token lookahead buffer size
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enum {tokenBufferSize = tokenLookahead + tokenGuard};
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Token tokens[tokenBufferSize]; // Circular buffer of recently read or lookahead tokens
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Token *nextToken; // Address of next Token in the circular buffer to be returned by get()
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int nTokensFwd; // Net number of Tokens on which unget() has been called; these Tokens are ahead of nextToken
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#ifdef DEBUG
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int nTokensBack; // Number of Tokens on which unget() can be called; these Tokens are beind nextToken
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bool savedPreferRegExp[tokenBufferSize]; // Circular buffer of saved values of preferRegExp to get() calls
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#endif
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bool lexingUnit; // True if lexing a unit identifier immediately following a number
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public:
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World &world;
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Reader reader;
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Lexer(World &world, const String &source, const String &sourceLocation, uint32 initialLineNum = 1);
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const Token &get(bool preferRegExp);
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const Token *eat(bool preferRegExp, Token::Kind kind);
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const Token &peek(bool preferRegExp);
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void redesignate(bool preferRegExp);
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void unget();
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uint32 getPos() const;
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private:
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void syntaxError(const char *message, uint backUp = 1);
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char16 getChar();
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char16 internalGetChar(char16 ch);
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char16 peekChar();
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char16 internalPeekChar(char16 ch);
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bool testChar(char16 ch);
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char16 lexEscape(bool unicodeOnly);
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bool lexIdentifier(String &s, bool allowLeadingDigit);
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bool lexNumeral();
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void lexString(String &s, char16 separator);
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void lexRegExp();
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void lexToken(bool preferRegExp);
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};
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#ifndef DEBUG
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inline void Lexer::redesignate(bool) {} // See description for the DEBUG version inside lexer.cpp
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#endif
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// Return the position of the first character of the next token, which must have been peeked.
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inline uint32 Lexer::getPos() const
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{
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ASSERT(nTokensFwd);
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return nextToken->getPos();
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}
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}
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#endif /* lexer_h___ */
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