Manual
Manual
Manual
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120 Bison 2.3<br />
%type<br />
[Directive]<br />
Bison declaration to declare nonterminals. See Section 3.7.5 [Nonterminal Symbols],<br />
page 56.<br />
$undefined<br />
[Symbol]<br />
The predefined token onto which all undefined values returned by yylex are mapped.<br />
It cannot be used in the grammar, rather, use error.<br />
%union<br />
[Directive]<br />
Bison declaration to specify several possible data types for semantic values. See<br />
Section 3.7.4 [The Collection of Value Types], page 55.<br />
YYABORT<br />
[Macro]<br />
Macro to pretend that an unrecoverable syntax error has occurred, by making yyparse<br />
return 1 immediately. The error reporting function yyerror is not called. See Section<br />
4.1 [The Parser Function yyparse], page 63.<br />
YYACCEPT<br />
[Macro]<br />
Macro to pretend that a complete utterance of the language has been read, by making<br />
yyparse return 0 immediately. See Section 4.1 [The Parser Function yyparse],<br />
page 63.<br />
YYBACKUP<br />
[Macro]<br />
Macro to discard a value from the parser stack and fake a look-ahead token. See<br />
Section 4.4 [Special Features for Use in Actions], page 68.<br />
yychar<br />
[Variable]<br />
External integer variable that contains the integer value of the look-ahead token. (In<br />
a pure parser, it is a local variable within yyparse.) Error-recovery rule actions may<br />
examine this variable. See Section 4.4 [Special Features for Use in Actions], page 68.<br />
yyclearin<br />
[Variable]<br />
Macro used in error-recovery rule actions. It clears the previous look-ahead token.<br />
See Chapter 6 [Error Recovery], page 83.<br />
YYDEBUG<br />
[Macro]<br />
Macro to define to equip the parser with tracing code. See Section 8.2 [Tracing Your<br />
Parser], page 95.<br />
yydebug<br />
[Variable]<br />
External integer variable set to zero by default. If yydebug is given a nonzero value,<br />
the parser will output information on input symbols and parser action. See Section 8.2<br />
[Tracing Your Parser], page 95.<br />
yyerrok<br />
[Macro]<br />
Macro to cause parser to recover immediately to its normal mode after a syntax error.<br />
See Chapter 6 [Error Recovery], page 83.<br />
YYERROR<br />
[Macro]<br />
Macro to pretend that a syntax error has just been detected: call yyerror and then<br />
perform normal error recovery if possible (see Chapter 6 [Error Recovery], page 83),