Bob Rossi <[EMAIL PROTECTED]> writes:
> How is the interface coming along? Do you see any other
> modifications that should take place?
Sorry, I'm not sure what you mean here. The interface is improving,
yes.
> {
> struct yypvars *ctx = yypvarsinit ();
> int status, ch;
> do {
> ch = yylex ();
> status = yypushparse (ctx, ch, &yylval, &yylloc);
> } while (status == YYPUSH_MORE);
> free (ctx);
> return status;
> }
>
> One potential problem that I can think of is that the push parser still
> allows the user to use the global variables yylval and yylloc.
It doesn't _require_ that, does it? It merely _allows_ it. One could
use code like this instead:
{
struct yypvars *ctx = yypvarsinit ();
YYSTYPE my_lval;
YYLTYPE my_lloc;
int status, ch;
do {
ch = my_lex (&my_lval, &my_lloc);
status = yypushparse (ctx, ch, &my_lval, &my_lloc);
} while (status == YYPUSH_MORE);
free (ctx);
return status;
}
This would be more reentrant, etc. We should use it as an example,
rather than the nonreentrant version.
> The push parser also has it's own version of these variables in the
> yypvars struct. I don't know if it's a good thing or a bad thing
> that we still use the global variables. At a minimum, it will allow
> users to not have to modify there lexers. What do you think?
I didn't remember that the push parser has its own copy. If the push
parser must have its own version of these variables *ctx, perhaps we
should make them visible to the user. E.g.,
{
struct yypvars *ctx = yypvarsinit ();
YYSTYPE *my_lval = yypv_lval (ctx);
YYLTYPE *my_loc = yypv_loc (ctx);
int status;
do {
status = yypushparse (ctx, my_lex (my_lval, my_loc));
} while (status == YYPUSH_MORE);
free (ctx);
return status;
}
or even this, assuming the lexer is changed to use yypv_lval,
yypv_loc:
{
struct yypvars *ctx = yypvarsinit ();
int status;
do
status = yypushparse (ctx, my_lex (ctx));
while (status == YYPUSH_MORE);
free (ctx);
return status;
}
> The push parser should also work under multiple contexts (ie
> aapushparse, bbpushparse). Can you think of a reason it currently
> wouldn't?
I don't see offhand, no.
