Skip to main content

Browse the archive

Staging
v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 2d8697f32c81f3db1e08ce198d5cebdeff5cc917 authored by Anthony Baxter on 18 September 2006, 06:51:50 UTC, committed by Anthony Baxter on 18 September 2006, 06:51:50 UTC 
Preparing for 2.5 final.
 
(damn, it's nice to see the line
  #define PY_VERSION              "2.5"
in patchlevel.h)
1 parent 347f3cc
Raw File
Tip revision: 2d8697f32c81f3db1e08ce198d5cebdeff5cc917 authored by Anthony Baxter on 18 September 2006, 06:51:50 UTC
Preparing for 2.5 final.
Tip revision: 2d8697f
bitset.c 

/* 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++;
}
back to top