/* Parser-tokenizer link implementation */

#include "pgenheaders.h"
#include "tokenizer.h"
#include "node.h"
#include "grammar.h"
#include "parser.h"
#include "parsetok.h"
#include "errcode.h"


/* Forward */
static int parsetok PROTO((struct tok_state *, grammar *, int, node **));


/* Parse input coming from a string.  Return error code, print some errors. */

int
parsestring(s, g, start, n_ret)
	char *s;
	grammar *g;
	int start;
	node **n_ret;
{
	struct tok_state *tok = tok_setups(s);
	int ret;
	
	if (tok == NULL) {
		fprintf(stderr, "no mem for tok_setups\n");
		return E_NOMEM;
	}
	ret = parsetok(tok, g, start, n_ret);
	if (ret == E_TOKEN || ret == E_SYNTAX) {
		fprintf(stderr, "String parsing error at line %d\n",
			tok->lineno);
	}
	tok_free(tok);
	return ret;
}


/* Parse input coming from a file.  Return error code, print some errors. */

int
parsefile(fp, filename, g, start, ps1, ps2, n_ret)
	FILE *fp;
	char *filename;
	grammar *g;
	int start;
	char *ps1, *ps2;
	node **n_ret;
{
	struct tok_state *tok = tok_setupf(fp, ps1, ps2);
	int ret;
	
	if (tok == NULL) {
		fprintf(stderr, "no mem for tok_setupf\n");
		return E_NOMEM;
	}
	ret = parsetok(tok, g, start, n_ret);
	if (ret == E_TOKEN || ret == E_SYNTAX) {
		char *p;
		fprintf(stderr, "Parsing error: file %s, line %d:\n",
						filename, tok->lineno);
		*tok->inp = '\0';
		if (tok->inp > tok->buf && tok->inp[-1] == '\n')
			tok->inp[-1] = '\0';
		fprintf(stderr, "%s\n", tok->buf);
		for (p = tok->buf; p < tok->cur; p++) {
			if (*p == '\t')
				putc('\t', stderr);
			else
				putc(' ', stderr);
		}
		fprintf(stderr, "^\n");
	}
	tok_free(tok);
	return ret;
}


/* Parse input coming from the given tokenizer structure.
   Return error code. */

static int
parsetok(tok, g, start, n_ret)
	struct tok_state *tok;
	grammar *g;
	int start;
	node **n_ret;
{
	parser_state *ps;
	int ret;
	
	if ((ps = newparser(g, start)) == NULL) {
		fprintf(stderr, "no mem for new parser\n");
		return E_NOMEM;
	}
	
	for (;;) {
		char *a, *b;
		int type;
		int len;
		char *str;
		
		type = tok_get(tok, &a, &b);
		if (type == ERRORTOKEN) {
			ret = tok->done;
			break;
		}
		len = b - a;
		str = NEW(char, len + 1);
		if (str == NULL) {
			fprintf(stderr, "no mem for next token\n");
			ret = E_NOMEM;
			break;
		}
		strncpy(str, a, len);
		str[len] = '\0';
		ret = addtoken(ps, (int)type, str, tok->lineno);
		if (ret != E_OK) {
			if (ret == E_DONE) {
				*n_ret = ps->p_tree;
				ps->p_tree = NULL;
			}
			else if (tok->lineno <= 1 && tok->done == E_EOF)
				ret = E_EOF;
			break;
		}
	}
	
	delparser(ps);
	return ret;
}