diff options
Diffstat (limited to 'c/pl.cpp')
| -rw-r--r-- | c/pl.cpp | 20 |
1 files changed, 20 insertions, 0 deletions
@@ -3,6 +3,8 @@ #include "pl.h" +/* Frame: Wrapper for opening and closing Prolog foreign frames. */ + Frame::Frame() { m_f = PL_open_foreign_frame(); @@ -18,6 +20,7 @@ void Frame::Close() PL_close_foreign_frame(m_f); } +/* Close foreign frame and invalidate associated data. */ void Frame::Discard() { PL_discard_foreign_frame(m_f); @@ -28,6 +31,8 @@ void Frame::Rewind() PL_rewind_foreign_frame(m_f); } +/* Mark: Wrapper for marking and releasing strings on the Prolog stack. */ + Mark::Mark() { PL_mark_string_buffers(&m_m); @@ -38,6 +43,8 @@ Mark::~Mark() PL_release_string_buffers_from_mark(m_m); } +/* Query: Wrapper for opening, solving and cutting Prolog query. */ + Query::Query(const module_t ctx, const predicate_t p, const term_t t0) { m_q = PL_open_query(ctx, PL_Q_CATCH_EXCEPTION, p, t0); @@ -55,6 +62,7 @@ int Query::Cut() return 0; } +/* Cut query and invalidate associated data. */ int Query::Close() { if (PL_close_query(m_q)) return 1; @@ -69,6 +77,7 @@ int Query::NextSolution() return 0; } +/* Convert Prolog term to normal or wide characters. */ int PL_get_tchars(const term_t t, TCHAR** const pTsz, const int iFlags) { #ifdef UNICODE @@ -83,6 +92,7 @@ int PL_get_tchars(const term_t t, TCHAR** const pTsz, const int iFlags) #endif } +/* Call nullary Prolog predicate, propagating Prolog exceptions. */ int Plx(const char* const szMod, const char* const szPred) { Frame f; @@ -90,3 +100,13 @@ int Plx(const char* const szMod, const char* const szPred) Query q(NULL, PL_predicate(szPred, 0, szMod), t); return q.NextSolution(); } + +/* Call nullary Prolog predicate, ignoring Prolog exceptions. */ +int Pl(const char* const szMod, const char* const szPred) +{ + try { + return Plx(szMod, szPred); + } catch (term_t& t) { + return 0; + } +} |