** Future changes:
The next major release will drop support for generating parsers in K&R C,
- and remove the definition of yystype (removal announced since Bison
- 1.875).
+ and remove the definitions of yystype and yyltype (removal announced since
+ Bison 1.875). YYPARSE_PARAM and YYLEX_PARAM, which were deprecated in
+ favor of %parse-param and %lex-param (introduced in Bison 1.875 too), will
+ no longer be supported.
** The generated header is included (yacc.c)
- "parsing stack overflow..." -> "parser stack overflow"
GLR parsers now report "parser stack overflow" as per the Bison manual.
+** %parse-param and %lex-param
+ The macros YYPARSE_PARAM and YYLEX_PARAM provide a means to pass
+ additional context to yyparse and yylex. They suffer from several
+ shortcomings:
+
+ - a single argument only can be added,
+ - their types are weak (void *),
+ - this context is not passed to anciliary functions such as yyerror,
+ - only yacc.c parsers support them.
+
+ The new %parse-param/%lex-param directives provide a more precise control.
+ For instance:
+
+ %parse-param {int *nastiness}
+ %lex-param {int *nastiness}
+ %parse-param {int *randomness}
+
+ results in the following signatures:
+
+ int yylex (int *nastiness);
+ int yyparse (int *nastiness, int *randomness);
+
+ or, if both %pure-parser and %locations are used:
+
+ int yylex (YYSTYPE *lvalp, YYLTYPE *llocp, int *nastiness);
+ int yyparse (int *nastiness, int *randomness);
+
** Bison now warns if it detects conflicting outputs to the same file,
e.g., it generates a warning for "bison -d -o foo.h foo.y" since
that command outputs both code and header to foo.h.