diff options
Diffstat (limited to 'c/pl.h')
| -rw-r--r-- | c/pl.h | 92 |
1 files changed, 92 insertions, 0 deletions
@@ -0,0 +1,92 @@ +#ifndef PL_H +#define PL_H + +#include <SWI-Prolog.h> + +int Plx(const char *, const char *); +struct Query +{ + Query(module_t ctx, predicate_t p, term_t t0); + ~Query(void); + int Cut(); + int Close(); + int NextSolution(); +private: + qid_t m_q; +}; + +#define DLVSIKEY 0 +#define DLVSIVALUE 1 + +/* Polymorphic aliases for PL_put_*, PL_get_*. */ +inline int PlPut(term_t t, int x) { return PL_put_integer(t, x); } +inline int PlPut(term_t t, long x) { return PL_put_integer(t, x); } +inline int PlPut(term_t t, long long x) { return PL_put_integer(t, x); } +inline int PlPut(term_t t, atom_t x) { return PL_put_atom(t, x); } +inline int PlPut(term_t t, char *x) { return PL_put_atom(t, PL_new_atom(x)); } +inline int PlPut(term_t t, const char *x) { return PL_put_atom(t, PL_new_atom(x)); } +inline int PlPut(term_t t, int *x) { return -1; } +inline int PlPut(term_t t, long *x) { return -1; } +inline int PlPut(term_t t, long long *x) { return -1; } +inline int PlPut(term_t t, atom_t *x) { return -1; } +inline int PlPut(term_t t, char **x) { return -1; } + +inline int PlGet(term_t t, int x) { return -1; } +inline int PlGet(term_t t, long x) { return -1; } +inline int PlGet(term_t t, long long x) { return -1; } +inline int PlGet(term_t t, atom_t x) { return -1; } +inline int PlGet(term_t t, char *x) { return -1; } +inline int PlGet(term_t t, const char *x) { return -1; } +inline int PlGet(term_t t, int *x) { return PL_get_integer(t, x); } +inline int PlGet(term_t t, long *x) { return PL_get_long(t, x); } +inline int PlGet(term_t t, long long *x) { return PL_get_int64(t, x); } +inline int PlGet(term_t t, atom_t *x) { return PL_get_atom(t, x); } +inline int PlGet(term_t t, char **x) { return PL_get_atom_chars(t, x); } + +/* Helper templates for Plx, Pl. */ +template <typename T> +int PlPutv(term_t t, T arg) { return PlPut(t, arg); } +template <typename T, typename ...R> +int PlPutv(term_t t, T arg, R... rest) { return PlPut(t, arg)? PlPutv(t+1, rest...): 0; } +template <typename T> +int PlGetv(term_t t, T arg) { return PlGet(t, arg); } +template <typename T, typename ...R> +int PlGetv(term_t t, T arg, R... rest) { return PlGet(t, arg)? PlGetv(t+1, rest...): 0; } +template <typename T> +int Countv(int i, T arg) { return i+1; } +template <typename T, typename ...R> +int Countv(int i, T arg, R... rest) { return Countv(i+1, rest...); } + +/* Call Prolog predicate, propagating Prolog exceptions. */ +template <typename ...T> +int Plx(const char *szMod, const char *szPred, T... args) +{ + int iArity = Countv(0, args...); + term_t t = PL_new_term_refs(iArity); + if (!PlPutv(t, args...)) return 0; + Query q(NULL, PL_predicate(szPred, iArity, szMod), t); + if (!q.NextSolution()) return 0; + if (!PlGetv(t, args...)) return 0; + return 1; +} + +/* Call Prolog predicate, ignoring Prolog exceptions. */ +inline int Pl(const char *szMod, const char *szPred) +{ + try { + return Plx(szMod, szPred); + } catch (term_t &t) { + return 0; + } +} +template <typename ...T> +int Pl(const char *szMod, const char *szPred, T... args) +{ + try { + return Plx(szMod, szPred, args...); + } catch (term_t &t) { + return 0; + } +} + +#endif |