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doc: add indexes

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* doc/bison.texi (Special Tokens): here.
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Akim Demaille
2021-12-18 17:52:01 +01:00
parent 6571c2d1b1
commit f8e8f57e9f
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doc/bison.texi
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@@ -7546,15 +7546,18 @@ utility can be used without change as the definition of @code{yylex}.
In addition to the user defined tokens, Bison generates a few special tokens In addition to the user defined tokens, Bison generates a few special tokens
that @code{yylex} may return. that @code{yylex} may return.
@findex YYEOF
The @code{YYEOF} token denotes the end of file, and signals to the parser The @code{YYEOF} token denotes the end of file, and signals to the parser
that there is nothing left afterwards. @xref{Calling Convention}, for an that there is nothing left afterwards. @xref{Calling Convention}, for an
example. example.
@findex YYUNDEF
Returning @code{YYUNDEF} tells the parser that some lexical error was found. Returning @code{YYUNDEF} tells the parser that some lexical error was found.
It will emit an error message about an ``invalid token'', and enter It will emit an error message about an ``invalid token'', and enter
error-recovery (@pxref{Error Recovery}). Returning an unknown token kind error-recovery (@pxref{Error Recovery}). Returning an unknown token kind
results in the exact same behavior. results in the exact same behavior.
@findex YYerror
Returning @code{YYerror} requires the parser to enter error-recovery Returning @code{YYerror} requires the parser to enter error-recovery
@emph{without} emitting an error message. This way the lexical analyzer can @emph{without} emitting an error message. This way the lexical analyzer can
produce an accurate error messages about the invalid input (something the produce an accurate error messages about the invalid input (something the