1 

     2 /* Bitset primitives used by the parser generator */

     3 

     4 #include "pgenheaders.h"

     5 #include "bitset.h"

     6 

     7 bitset

     8 newbitset(int nbits)

     9 {

    10 	int nbytes = NBYTES(nbits);

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

    12 	

    13 	if (ss == NULL)

    14 		Py_FatalError("no mem for bitset");

    15 	

    16 	ss += nbytes;

    17 	while (--nbytes >= 0)

    18 		*--ss = 0;

    19 	return ss;

    20 }

    21 

    22 void

    23 delbitset(bitset ss)

    24 {

    25 	PyObject_FREE(ss);

    26 }

    27 

    28 int

    29 addbit(bitset ss, int ibit)

    30 {

    31 	int ibyte = BIT2BYTE(ibit);

    32 	BYTE mask = BIT2MASK(ibit);

    33 	

    34 	if (ss[ibyte] & mask)

    35 		return 0; /* Bit already set */

    36 	ss[ibyte] |= mask;

    37 	return 1;

    38 }

    39 

    40 #if 0 /* Now a macro */

    41 int

    42 testbit(bitset ss, int ibit)

    43 {

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

    45 }

    46 #endif

    47 

    48 int

    49 samebitset(bitset ss1, bitset ss2, int nbits)

    50 {

    51 	int i;

    52 	

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

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

    55 			return 0;

    56 	return 1;

    57 }

    58 

    59 void

    60 mergebitset(bitset ss1, bitset ss2, int nbits)

    61 {

    62 	int i;

    63 	

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

    65 		*ss1++ |= *ss2++;

    66 }