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%{
#include <stdio.h>
#include "tree.h"
#include "parser.h"
#include "lexer.h"
void yyerror (struct forest **root, yyscan_t scanner, char const *);
%}
%code requires {
typedef void* yyscan_t;
}
%header "parser.h"
%define parse.trace
%define api.pure
%token
TREE_START
TREE_END
<exp> VAL
FAILURE
%parse-param {struct forest **root}
%param { yyscan_t scanner }
%union {
struct tree* exp;
struct forest* forest;
}
%type <exp> tree
%type <forest> forest
%type <exp> tree_or_val
%%
/* The grammar */
forest:
%empty { $$ = NULL; }
| forest[F] tree_or_val[T]
{
if ($F != NULL) {
plant_tree($F, $T);
$$ = $F;
} else {
$$ = forest_alloc();
plant_tree($$, $T);
}
*root = $$;
};
tree: TREE_START forest[F] TREE_END
{
$$ = tree_alloc(parenthesized, NULL, 0);
$$->children = $F;
};
tree_or_val: tree | VAL;
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