c/pl.cpp


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#include <SWI-Prolog.h>

#include "pl.h"

Query::Query(module_t ctx, predicate_t p, term_t t0)
{
	m_q = PL_open_query(ctx, PL_Q_CATCH_EXCEPTION, p, t0);
}

Query::~Query()
{
	PL_cut_query(m_q);
}

int Query::Cut()
{
	if (PL_cut_query(m_q)) return 1;
	if (term_t t = PL_exception(m_q)) throw t;
	return 0;
}

int Query::Close()
{
	if (PL_close_query(m_q)) return 1;
	if (term_t t = PL_exception(m_q)) throw t;
	return 0;
}

int Query::NextSolution()
{
	if (PL_next_solution(m_q)) return 1;
	if (term_t t = PL_exception(m_q)) throw t;
	return 0;
}

int Plx(const char *szMod, const char *szPred)
{
	term_t t = PL_new_term_refs(0);
	Query q(NULL, PL_predicate(szPred, 0, szMod), t);
	return q.NextSolution();
}