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Bison Symbols

@

A token name reserved for error recovery. This token may be used in grammar rules so as to allow the Bison parser to recognize an error in the grammar without halting the process. In effect, a sentence containing an error may be recognized as valid. On a parse error, the token error becomes the current look-ahead token. Actions corresponding to error are then executed, and the look-ahead token is reset to the token that originally caused the violation. See section Error Recovery.

@

Macro to pretend that an unrecoverable syntax error has occurred, by making yyparse return 1 immediately. The error reporting function yyerror is not called. @xref{Parser Function, ,The Parser Function

}yyparse}.

@

Macro to pretend that a complete utterance of the language has been read, by making yyparse return 0 immediately. @xref{Parser Function, ,The Parser Function

}yyparse}.

@

Macro to discard a value from the parser stack and fake a look-ahead token. See section Special Features for Use in Actions.

@

Macro to pretend that a syntax error has just been detected: call yyerror and then perform normal error recovery if possible (see section Error Recovery), or (if recovery is impossible) make yyparse return 1. See section Error Recovery.

@

Macro that you define with #define in the Bison declarations section to request verbose, specific error message strings when yyerror is called.

@

Macro for specifying the initial size of the parser stack. See section Stack Overflow, and How to Avoid It.

@

Macro for the data type of yylloc; a structure with four members. See section Textual Positions of Tokens.

@

Macro for specifying the maximum size of the parser stack. See section Stack Overflow, and How to Avoid It.

@

Macro whose value indicates whether the parser is recovering from a syntax error. See section Special Features for Use in Actions.

@

Macro for the data type of semantic values; int by default. See section Data Types of Semantic Values.

@

External integer variable that contains the integer value of the current look-ahead token. (In a pure parser, it is a local variable within yyparse.) Error-recovery rule actions may examine this variable. See section Special Features for Use in Actions.

@

Macro used in error-recovery rule actions. It clears the previous look-ahead token. See section Error Recovery.

@

External integer variable set to zero by default. If yydebug is given a nonzero value, the parser will output information on input symbols and parser action. See section Debugging Your Parser.

@

Macro to cause parser to recover immediately to its normal mode after a parse error. See section Error Recovery.

@

User-supplied function to be called by yyparse on error. The function receives one argument, a pointer to a character string containing an error message. @xref{Error Reporting, ,The Error Reporting Function

}yyerror}.

@

User-supplied lexical analyzer function, called with no arguments to get the next token. @xref{Lexical, ,The Lexical Analyzer Function

}yylex}.

@

External variable in which yylex should place the semantic value associated with a token. (In a pure parser, it is a local variable within yyparse, and its address is passed to yylex.) See section Semantic Values of Tokens.

@

External variable in which yylex should place the line and column numbers associated with a token. (In a pure parser, it is a local variable within yyparse, and its address is passed to yylex.) You can ignore this variable if you don't use the `@' feature in the grammar actions. See section Textual Positions of Tokens.

@

Global variable which Bison increments each time there is a parse error. (In a pure parser, it is a local variable within yyparse.) @xref{Error Reporting, ,The Error Reporting Function

}yyerror}.

@

The parser function produced by Bison; call this function to start parsing. @xref{Parser Function, ,The Parser Function

}yyparse}.

@

Bison declaration to assign left associativity to token(s). See section Operator Precedence.

@

Bison declaration to assign nonassociativity to token(s). See section Operator Precedence.

@

Bison declaration to assign a precedence to a specific rule. See section Context-Dependent Precedence.

@

Bison declaration to request a pure (reentrant) parser. See section A Pure (Reentrant) Parser.

@

Bison declaration to assign right associativity to token(s). See section Operator Precedence.

@

Bison declaration to specify the start symbol. See section The Start-Symbol.

@

Bison declaration to declare token(s) without specifying precedence. See section Token Type Names.

@

Bison declaration to declare nonterminals. See section Nonterminal Symbols.

@

Bison declaration to specify several possible data types for semantic values. See section The Collection of Value Types.

These are the punctuation and delimiters used in Bison input:

@

Delimiter used to separate the grammar rule section from the Bison declarations section or the additional C code section. See section The Overall Layout of a Bison Grammar.

@

All code listed between `%{' and `%}' is copied directly to the output file uninterpreted. Such code forms the "C declarations" section of the input file. See section Outline of a Bison Grammar.

@

Comment delimiters, as in C.

@

Separates a rule's result from its components. See section Syntax of Grammar Rules.

@

Terminates a rule. See section Syntax of Grammar Rules.

@

Separates alternate rules for the same result nonterminal. See section Syntax of Grammar Rules.

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