miller/c/dsls/lemon_set.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lemon_set.h"

/*
** Set manipulation routines for the LEMON parser generator.
*/

static int size = 0;

/* Set the set size */
void SetSize(int n) {
	size = n+1;
}

/* Allocate a new set */
char *SetNew() {
	char *s;
	int i;
	s = (char*)malloc (size) ;
	if (s==0) {
		extern void memory_error();
		memory_error();
	}
	for(i=0; i<size; i++) s[i] = 0;
	return s;
}

/* Deallocate a set */
void SetFree(char *s) {
	free(s);
}

/* Add a new element to the set.  Return TRUE if the element was added
** and FALSE if it was already there. */
int SetAdd(char *s, int e) {
	int rv;
	rv = s[e];
	s[e] = 1;
	return !rv;
}

/* Add every element of s2 to s1.  Return TRUE if s1 changes. */
int SetUnion(char *s1, char *s2) {
	int i, progress;
	progress = 0;
	for(i=0; i<size; i++){
		if (s2[i]==0)  continue;
		if (s1[i]==0) {
			progress = 1;
			s1[i] = 1;
		}
	}
	return progress;
}