diff options
Diffstat (limited to 'Parser/bitset.c')
-rw-r--r-- | Parser/bitset.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/Parser/bitset.c b/Parser/bitset.c new file mode 100644 index 0000000..f5bfd41 --- /dev/null +++ b/Parser/bitset.c @@ -0,0 +1,66 @@ + +/* 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++; +} |