/Parser/bitset.c
http://unladen-swallow.googlecode.com/ · C · 66 lines · 52 code · 13 blank · 1 comment · 9 complexity · eac35f096816dd44570f9fc1d07709e0 MD5 · raw file
- /* 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++;
- }