1 | #ifndef INC_Parser_hpp__ |
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2 | #define INC_Parser_hpp__ |
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3 | |
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4 | /* ANTLR Translator Generator |
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5 | * Project led by Terence Parr at http://www.jGuru.com |
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6 | * Software rights: http://www.antlr.org/license.html |
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7 | * |
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8 | * $Id: //depot/code/org.antlr/release/antlr-2.7.7/lib/cpp/antlr/Parser.hpp#2 $ |
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9 | */ |
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10 | |
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11 | #include <antlr/config.hpp> |
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12 | |
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13 | #include <iostream> |
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14 | #include <exception> |
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15 | |
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16 | #include <antlr/BitSet.hpp> |
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17 | #include <antlr/TokenBuffer.hpp> |
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18 | #include <antlr/RecognitionException.hpp> |
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19 | #include <antlr/MismatchedTokenException.hpp> |
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20 | #include <antlr/ASTFactory.hpp> |
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21 | #include <antlr/ParserSharedInputState.hpp> |
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22 | |
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23 | #ifdef ANTLR_CXX_SUPPORTS_NAMESPACE |
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24 | namespace antlr { |
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25 | #endif |
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26 | |
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27 | extern bool DEBUG_PARSER; |
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28 | |
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29 | /** A generic ANTLR parser (LL(k) for k>=1) containing a bunch of |
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30 | * utility routines useful at any lookahead depth. We distinguish between |
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31 | * the LL(1) and LL(k) parsers because of efficiency. This may not be |
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32 | * necessary in the near future. |
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33 | * |
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34 | * Each parser object contains the state of the parse including a lookahead |
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35 | * cache (the form of which is determined by the subclass), whether or |
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36 | * not the parser is in guess mode, where tokens come from, etc... |
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37 | * |
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38 | * <p> |
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39 | * During <b>guess</b> mode, the current lookahead token(s) and token type(s) |
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40 | * cache must be saved because the token stream may not have been informed |
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41 | * to save the token (via <tt>mark</tt>) before the <tt>try</tt> block. |
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42 | * Guessing is started by: |
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43 | * <ol> |
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44 | * <li>saving the lookahead cache. |
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45 | * <li>marking the current position in the TokenBuffer. |
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46 | * <li>increasing the guessing level. |
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47 | * </ol> |
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48 | * |
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49 | * After guessing, the parser state is restored by: |
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50 | * <ol> |
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51 | * <li>restoring the lookahead cache. |
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52 | * <li>rewinding the TokenBuffer. |
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53 | * <li>decreasing the guessing level. |
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54 | * </ol> |
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55 | * |
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56 | * @see antlr.Token |
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57 | * @see antlr.TokenBuffer |
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58 | * @see antlr.TokenStream |
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59 | * @see antlr.LL1Parser |
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60 | * @see antlr.LLkParser |
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61 | * |
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62 | * @todo add constructors with ASTFactory. |
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63 | */ |
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64 | class ANTLR_API Parser { |
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65 | protected: |
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66 | Parser(TokenBuffer& input) |
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67 | : inputState(new ParserInputState(input)), astFactory(0), traceDepth(0) |
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68 | { |
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69 | } |
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70 | Parser(TokenBuffer* input) |
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71 | : inputState(new ParserInputState(input)), astFactory(0), traceDepth(0) |
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72 | { |
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73 | } |
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74 | Parser(const ParserSharedInputState& state) |
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75 | : inputState(state), astFactory(0), traceDepth(0) |
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76 | { |
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77 | } |
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78 | public: |
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79 | virtual ~Parser() |
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80 | { |
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81 | } |
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82 | |
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83 | /** Return the token type of the ith token of lookahead where i=1 |
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84 | * is the current token being examined by the parser (i.e., it |
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85 | * has not been matched yet). |
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86 | */ |
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87 | virtual int LA(unsigned int i)=0; |
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88 | |
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89 | /// Return the i-th token of lookahead |
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90 | virtual RefToken LT(unsigned int i)=0; |
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91 | |
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92 | /** DEPRECATED! Specify the factory to be used during tree building. (Compulsory) |
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93 | * Setting the factory is nowadays compulsory. |
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94 | * @see setASTFactory |
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95 | */ |
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96 | virtual void setASTNodeFactory( ASTFactory *factory ) |
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97 | { |
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98 | astFactory = factory; |
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99 | } |
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100 | /** Specify the factory to be used during tree building. (Compulsory) |
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101 | * Setting the factory is nowadays compulsory. |
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102 | */ |
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103 | virtual void setASTFactory( ASTFactory *factory ) |
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104 | { |
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105 | astFactory = factory; |
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106 | } |
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107 | /** Return a pointer to the ASTFactory used. |
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108 | * So you might use it in subsequent treewalkers or to reload AST's |
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109 | * from disk. |
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110 | */ |
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111 | virtual ASTFactory* getASTFactory() |
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112 | { |
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113 | return astFactory; |
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114 | } |
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115 | /** Get the root AST node of the generated AST. When using a custom AST type |
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116 | * or heterogenous AST's, you'll have to convert it to the right type |
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117 | * yourself. |
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118 | */ |
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119 | virtual RefAST getAST() = 0; |
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120 | |
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121 | /// Return the filename of the input file. |
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122 | virtual inline ANTLR_USE_NAMESPACE(std)string getFilename() const |
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123 | { |
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124 | return inputState->filename; |
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125 | } |
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126 | /// Set the filename of the input file (used for error reporting). |
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127 | virtual void setFilename(const ANTLR_USE_NAMESPACE(std)string& f) |
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128 | { |
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129 | inputState->filename = f; |
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130 | } |
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131 | |
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132 | virtual void setInputState(ParserSharedInputState state) |
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133 | { |
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134 | inputState = state; |
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135 | } |
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136 | virtual inline ParserSharedInputState getInputState() const |
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137 | { |
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138 | return inputState; |
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139 | } |
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140 | |
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141 | /// Get another token object from the token stream |
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142 | virtual void consume()=0; |
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143 | /// Consume tokens until one matches the given token |
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144 | virtual void consumeUntil(int tokenType) |
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145 | { |
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146 | while (LA(1) != Token::EOF_TYPE && LA(1) != tokenType) |
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147 | consume(); |
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148 | } |
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149 | |
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150 | /// Consume tokens until one matches the given token set |
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151 | virtual void consumeUntil(const BitSet& set) |
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152 | { |
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153 | while (LA(1) != Token::EOF_TYPE && !set.member(LA(1))) |
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154 | consume(); |
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155 | } |
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156 | |
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157 | /** Make sure current lookahead symbol matches token type <tt>t</tt>. |
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158 | * Throw an exception upon mismatch, which is catch by either the |
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159 | * error handler or by the syntactic predicate. |
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160 | */ |
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161 | virtual void match(int t) |
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162 | { |
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163 | if ( DEBUG_PARSER ) |
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164 | { |
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165 | traceIndent(); |
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166 | ANTLR_USE_NAMESPACE(std)cout << "enter match(" << t << ") with LA(1)=" << LA(1) << ANTLR_USE_NAMESPACE(std)endl; |
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167 | } |
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168 | if ( LA(1) != t ) |
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169 | { |
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170 | if ( DEBUG_PARSER ) |
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171 | { |
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172 | traceIndent(); |
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173 | ANTLR_USE_NAMESPACE(std)cout << "token mismatch: " << LA(1) << "!=" << t << ANTLR_USE_NAMESPACE(std)endl; |
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174 | } |
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175 | throw MismatchedTokenException(getTokenNames(), getNumTokens(), LT(1), t, false, getFilename()); |
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176 | } |
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177 | else |
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178 | { |
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179 | // mark token as consumed -- fetch next token deferred until LA/LT |
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180 | consume(); |
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181 | } |
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182 | } |
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183 | |
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184 | virtual void matchNot(int t) |
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185 | { |
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186 | if ( LA(1)==t ) |
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187 | { |
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188 | // Throws inverted-sense exception |
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189 | throw MismatchedTokenException(getTokenNames(), getNumTokens(), LT(1), t, true, getFilename()); |
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190 | } |
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191 | else |
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192 | { |
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193 | // mark token as consumed -- fetch next token deferred until LA/LT |
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194 | consume(); |
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195 | } |
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196 | } |
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197 | |
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198 | /** Make sure current lookahead symbol matches the given set |
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199 | * Throw an exception upon mismatch, which is catch by either the |
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200 | * error handler or by the syntactic predicate. |
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201 | */ |
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202 | virtual void match(const BitSet& b) |
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203 | { |
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204 | if ( DEBUG_PARSER ) |
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205 | { |
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206 | traceIndent(); |
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207 | ANTLR_USE_NAMESPACE(std)cout << "enter match(" << "bitset" /*b.toString()*/ |
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208 | << ") with LA(1)=" << LA(1) << ANTLR_USE_NAMESPACE(std)endl; |
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209 | } |
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210 | if ( !b.member(LA(1)) ) |
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211 | { |
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212 | if ( DEBUG_PARSER ) |
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213 | { |
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214 | traceIndent(); |
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215 | ANTLR_USE_NAMESPACE(std)cout << "token mismatch: " << LA(1) << " not member of " |
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216 | << "bitset" /*b.toString()*/ << ANTLR_USE_NAMESPACE(std)endl; |
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217 | } |
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218 | throw MismatchedTokenException(getTokenNames(), getNumTokens(), LT(1), b, false, getFilename()); |
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219 | } |
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220 | else |
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221 | { |
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222 | // mark token as consumed -- fetch next token deferred until LA/LT |
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223 | consume(); |
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224 | } |
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225 | } |
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226 | |
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227 | /** Mark a spot in the input and return the position. |
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228 | * Forwarded to TokenBuffer. |
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229 | */ |
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230 | virtual inline unsigned int mark() |
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231 | { |
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232 | return inputState->getInput().mark(); |
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233 | } |
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234 | /// rewind to a previously marked position |
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235 | virtual inline void rewind(unsigned int pos) |
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236 | { |
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237 | inputState->getInput().rewind(pos); |
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238 | } |
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239 | /** called by the generated parser to do error recovery, override to |
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240 | * customize the behaviour. |
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241 | */ |
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242 | virtual void recover(const RecognitionException& ex, const BitSet& tokenSet) |
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243 | { |
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244 | consume(); |
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245 | consumeUntil(tokenSet); |
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246 | } |
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247 | |
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248 | /// Parser error-reporting function can be overridden in subclass |
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249 | virtual void reportError(const RecognitionException& ex); |
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250 | /// Parser error-reporting function can be overridden in subclass |
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251 | virtual void reportError(const ANTLR_USE_NAMESPACE(std)string& s); |
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252 | /// Parser warning-reporting function can be overridden in subclass |
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253 | virtual void reportWarning(const ANTLR_USE_NAMESPACE(std)string& s); |
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254 | |
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255 | /// get the token name for the token number 'num' |
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256 | virtual const char* getTokenName(int num) const = 0; |
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257 | /// get a vector with all token names |
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258 | virtual const char* const* getTokenNames() const = 0; |
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259 | /** Get the number of tokens defined. |
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260 | * This one should be overridden in subclasses. |
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261 | */ |
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262 | virtual int getNumTokens(void) const = 0; |
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263 | |
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264 | /** Set or change the input token buffer */ |
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265 | // void setTokenBuffer(TokenBuffer<Token>* t); |
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266 | |
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267 | virtual void traceIndent(); |
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268 | virtual void traceIn(const char* rname); |
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269 | virtual void traceOut(const char* rname); |
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270 | protected: |
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271 | // void setTokenNames(const char** tokenNames_); |
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272 | |
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273 | ParserSharedInputState inputState; |
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274 | |
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275 | // /// AST return value for a rule is squirreled away here |
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276 | // RefAST returnAST; |
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277 | |
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278 | /// AST support code; parser and treeparser delegate to this object |
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279 | ASTFactory *astFactory; |
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280 | |
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281 | // used to keep track of the indentation for the trace |
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282 | int traceDepth; |
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283 | |
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284 | /** Utility class which allows tracing to work even when exceptions are |
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285 | * thrown. |
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286 | */ |
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287 | class Tracer { /*{{{*/ |
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288 | private: |
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289 | Parser* parser; |
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290 | const char* text; |
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291 | public: |
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292 | Tracer(Parser* p,const char * t) |
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293 | : parser(p), text(t) |
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294 | { |
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295 | parser->traceIn(text); |
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296 | } |
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297 | ~Tracer() |
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298 | { |
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299 | #ifdef ANTLR_CXX_SUPPORTS_UNCAUGHT_EXCEPTION |
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300 | // Only give trace if there's no uncaught exception.. |
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301 | if(!ANTLR_USE_NAMESPACE(std)uncaught_exception()) |
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302 | #endif |
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303 | parser->traceOut(text); |
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304 | } |
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305 | private: |
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306 | Tracer(const Tracer&); // undefined |
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307 | const Tracer& operator=(const Tracer&); // undefined |
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308 | /*}}}*/ |
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309 | }; |
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310 | private: |
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311 | Parser(const Parser&); // undefined |
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312 | const Parser& operator=(const Parser&); // undefined |
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313 | }; |
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314 | |
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315 | #ifdef ANTLR_CXX_SUPPORTS_NAMESPACE |
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316 | } |
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317 | #endif |
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318 | |
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319 | #endif //INC_Parser_hpp__ |
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