Re: Why was YYLEX_PARAM "deprecated"?

[Akim Demaille]

 John> Why was YYLEX_PARAM marked "deprecated"?

Because using %lex-param is promoted now.  But it is true that for
some reason I don't remember the documentation for %lex-param was
disabled :(  It is high time to restore it.

@c For now, do not document %lex-param and %parse-param, since it's
@c not clear that the current behavior is stable enough.  For example,
@c we may need to add %error-param.
@clear documentparam

@ifset documentparam
If you use a reentrant parser, you can optionally pass additional
parameter information to it in a reentrant way.  To do so, use the
declaration @code{%parse-param}:

@deffn {Directive} %parse-param @address@hidden@}
@findex %parse-param
Declare that an argument declared by @code{argument-declaration} is an
additional @code{yyparse} argument.
The @var{argument-declaration} is used when declaring
functions or prototypes.  The last identifier in
@var{argument-declaration} must be the argument name.
@end deffn

Here's an example.  Write this in the parser:

@example
%parse-param @{int address@hidden
%parse-param @{int address@hidden
@end example

@noindent
Then call the parser like this:

@example
@{
  int nastiness, randomness;
  @dots{}  /* @r{Store proper data in @code{nastiness} and @code{randomness}.}  
*/
  value = yyparse (&nastiness, &randomness);
  @dots{}
@}
@end example

@noindent
In the grammar actions, use expressions like this to refer to the data:

@example
exp: @dots{}    @{ @dots{}; *randomness += 1; @dots{} @}
@end example
@end ifset




I don't think we need a error-param at all.