/* Bitset primitives used by the parser generator */

#include "pgenheaders.h"

#include "bitset.h"

bitset

newbitset(int nbits)

{

	int nbytes = NBYTES(nbits);

	bitset ss = (char *)PyObject_MALLOC(sizeof(BYTE) *  nbytes);

	if (ss == NULL)

		Py_FatalError("no mem for bitset");

	ss += nbytes;

	while (--nbytes >= 0)

		*--ss = 0;

	return ss;

}

void

delbitset(bitset ss)

{

	PyObject_FREE(ss);

}

int

addbit(bitset ss, int ibit)

{

	int ibyte = BIT2BYTE(ibit);

	BYTE mask = BIT2MASK(ibit);

	if (ss[ibyte] & mask)

		return 0; /* Bit already set */

	ss[ibyte] |= mask;

	return 1;

}

#if 0 /* Now a macro */

int

testbit(bitset ss, int ibit)

{

	return (ss[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0;

}

#endif

int

samebitset(bitset ss1, bitset ss2, int nbits)

{

	int i;

	for (i = NBYTES(nbits); --i >= 0; )

		if (*ss1++ != *ss2++)

			return 0;

	return 1;

}

void

mergebitset(bitset ss1, bitset ss2, int nbits)

{

	int i;

	for (i = NBYTES(nbits); --i >= 0; )

		*ss1++ |= *ss2++;

}