X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/6ce4b4ff1b761a0408cf94abb308fac9b55edd3d..39bace5da815c0290ce5e84628ca7615307b8349:/doc/bison.texi diff --git a/doc/bison.texi b/doc/bison.texi index 4a4bd600..cd5e440e 100644 --- a/doc/bison.texi +++ b/doc/bison.texi @@ -366,6 +366,7 @@ Java Parsers * Java Parser Interface:: Instantiating and running the parser * Java Scanner Interface:: Specifying the scanner for the parser * Java Action Features:: Special features for use in actions +* Java Push Parser Interface:: Instantiating and running the a push parser * Java Differences:: Differences between C/C++ and Java Grammars * Java Declarations Summary:: List of Bison declarations used with Java @@ -10064,18 +10065,16 @@ A category can be turned off by prefixing its name with @samp{no-}. For instance, @option{-Wno-yacc} will hide the warnings about POSIX Yacc incompatibilities. -@item -Werror[=@var{category}] -@itemx -Wno-error[=@var{category}] -Enable warnings falling in @var{category}, and treat them as errors. If no -@var{category} is given, it defaults to making all enabled warnings into errors. +@item -Werror +Turn enabled warnings for every @var{category} into errors, unless they are +explicitly disabled by @option{-Wno-error=@var{category}}. + +@item -Werror=@var{category} +Enable warnings falling in @var{category}, and treat them as errors. @var{category} is the same as for @option{--warnings}, with the exception that it may not be prefixed with @samp{no-} (see above). -Prefixed with @samp{no}, it deactivates the error treatment for this -@var{category}. However, the warning itself won't be disabled, or enabled, by -this option. - Note that the precedence of the @samp{=} and @samp{,} operators is such that the following commands are @emph{not} equivalent, as the first will not treat S/R conflicts as errors. @@ -10085,6 +10084,14 @@ $ bison -Werror=yacc,conflicts-sr input.y $ bison -Werror=yacc,error=conflicts-sr input.y @end example +@item -Wno-error +Do not turn enabled warnings for every @var{category} into errors, unless +they are explicitly enabled by @option{-Werror=@var{category}}. + +@item -Wno-error=@var{category} +Deactivate the error treatment for this @var{category}. However, the warning +itself won't be disabled, or enabled, by this option. + @item -f [@var{feature}] @itemx --feature[=@var{feature}] Activate miscellaneous @var{feature}. @var{feature} can be one of: @@ -11500,6 +11507,7 @@ main (int argc, char *argv[]) * Java Parser Interface:: Instantiating and running the parser * Java Scanner Interface:: Specifying the scanner for the parser * Java Action Features:: Special features for use in actions +* Java Push Parser Interface:: Instantiating and running the a push parser * Java Differences:: Differences between C/C++ and Java Grammars * Java Declarations Summary:: List of Bison declarations used with Java @end menu @@ -11811,7 +11819,6 @@ The return type can be changed using @samp{%define api.value.type @{@var{class-name}@}}. @end deftypemethod - @node Java Action Features @subsection Special Features for Use in Java Actions @@ -11890,6 +11897,73 @@ instance in use. The @code{Location} and @code{Position} parameters are available only if location tracking is active. @end deftypefn +@node Java Push Parser Interface +@subsection Java Push Parser Interface +@c - define push_parse +@findex %define api.push-pull + +(The current push parsing interface is experimental and may evolve. More +user feedback will help to stabilize it.) + +Normally, Bison generates a pull parser for Java. +The following Bison declaration says that you want the parser to be a push +parser (@pxref{%define Summary,,api.push-pull}): + +@example +%define api.push-pull push +@end example + +Most of the discussion about the Java pull Parser Interface, (@pxref{Java +Parser Interface}) applies to the push parser interface as well. + +When generating a push parser, the method @code{push_parse} is created with +the following signature (depending on if locations are enabled). + +@deftypemethod {YYParser} {void} push_parse ({int} @var{token}, {Object} @var{yylval}) +@deftypemethodx {YYParser} {void} push_parse ({int} @var{token}, {Object} @var{yylval}, {Location} @var{yyloc}) +@deftypemethodx {YYParser} {void} push_parse ({int} @var{token}, {Object} @var{yylval}, {Position} @var{yypos}) +@end deftypemethod + +The primary difference with respect to a pull parser is that the parser +method @code{push_parse} is invoked repeatedly to parse each token. This +function is available if either the "%define api.push-pull push" or "%define +api.push-pull both" declaration is used (@pxref{%define +Summary,,api.push-pull}). The @code{Location} and @code{Position} +parameters are available only if location tracking is active. + +The value returned by the @code{push_parse} method is one of the following +four constants: @code{YYABORT}, @code{YYACCEPT}, @code{YYERROR}, or +@code{YYPUSH_MORE}. This new value, @code{YYPUSH_MORE}, may be returned if +more input is required to finish parsing the grammar. + +If api.push-pull is declared as @code{both}, then the generated parser class +will also implement the @code{parse} method. This method's body is a loop +that repeatedly invokes the scanner and then passes the values obtained from +the scanner to the @code{push_parse} method. + +There is one additional complication. Technically, the push parser does not +need to know about the scanner (i.e. an object implementing the +@code{YYParser.Lexer} interface), but it does need access to the +@code{yyerror} method. Currently, the @code{yyerror} method is defined in +the @code{YYParser.Lexer} interface. Hence, an implementation of that +interface is still required in order to provide an implementation of +@code{yyerror}. The current approach (and subject to change) is to require +the @code{YYParser} constructor to be given an object implementing the +@code{YYParser.Lexer} interface. This object need only implement the +@code{yyerror} method; the other methods can be stubbed since they will +never be invoked. The simplest way to do this is to add a trivial scanner +implementation to your grammar file using whatever implementation of +@code{yyerror} is desired. The following code sample shows a simple way to +accomplish this. + +@example +%code lexer +@{ + public Object getLVal () @{return null;@} + public int yylex () @{return 0;@} + public void yyerror (String s) @{System.err.println(s);@} +@} +@end example @node Java Differences @subsection Differences between C/C++ and Java Grammars