Re: Bison yyparse return array of values

[Laura Morales]

I'm looking at this example http://esr.ibiblio.org/?p=6341 which is using these 
slightly different instructions

%define api.pure full
%lex-param {yyscan_t scanner}
%parse-param {yyscan_t scanner}

and then add another parameter to handle the output

%define api.pure full
%lex-param {yyscan_t scanner} {cvs_file *cvsfile}
%parse-param {yyscan_t scanner} {cvs_file *cvsfile}

Can somebody please explain the meaning of "yyscan_t scanner" and if I can omit 
it?

================
%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct elem {
char *val;
struct elem *next;
} elem_t;

elem_t *add_word(elem_t *words, char *val) {
elem_t *word = (elem_t *)malloc(sizeof(elem_t));
if (word == NULL) {
fprintf (stderr, "%s", "malloc failed");
exit(1); }
word->val = val;
word->next = words;
return word;
}
%}

%output "parser.c"
%defines "parser.h"

%name-prefix "yy1"
%define api.pure full
%parse-param { elem_t **words };

%union {
char *str;
}

%token <str> WORD

%start Input

%%

Input
: WORD { *words = add_word(NULL, $1);
printf("word: %s\n", yylval.str); }
| Input WORD { *words = add_word(*words, $2);
printf("word: %s\n", yylval.str); }
;

%%

int main() {
elem_t *words = NULL;
yy1parse(&words);

int i = 0;
while (words != NULL) {
i++;
words = words->next;
}

fprintf(stdout, "Parsed %d WORDS\n", i);
}

void yy1error(char *error) {
fprintf(stderr, "%s", error);
}

int yy1lex(YYSTYPE *lvalp) {
static int i = 0;
while (i++ < 100) {
lvalp->str = "testWord";
return WORD;
}

return 0;
}
================