// whereTerm != null : for persistent predicates only
// put the predicate definition (if found) into the TermNode if it is not already there
public bool FindPredicateDefinition(PredicateStorage predicateStorage, Term whereTerm)
{
if (predDescr == null) predDescr = predicateStorage[term.KbKey];
if (predDescr == null) return false;
#if arg1index
Term arg;
if (predDescr.IsFirstArgIndexed)
{
if ((arg = term.Arg (0)).IsVar)
nextClause = predDescr.FirstArgVarClause ();
else // not a variable
{
nextClause = predDescr.FirstArgNonvarClause (arg.Functor);
// check whether there is an indexed var clause
if (nextClause == null) nextClause = predDescr.FirstArgVarClause ();
// if the above failed, the entire predicate fails (no unification possible)
if (nextClause == null) nextClause = ClauseNode.FAIL; // "fail."
}
if (nextClause == null)
nextClause = predDescr.GetClauseList (term, whereTerm); // GetClauseList: in PredicateStorage
}
else // not indexed
#endif
nextClause = predDescr.GetClauseList(term, whereTerm); // GetClauseList: in PredicateStorage
return true;
}
private void Initialize()
{
ps = (PredicateStorage)parser_arg[0];
Add1000Operators();
terminalTable.Remove("module"); // will be temporarily set after an initial ':-' only
terminalTable.Remove("persistent"); // ...
terminalTable.Remove("undef_pred_action"); // ...
}
public bool FindPredicateDefinition(PredicateStorage predicateStorage)
{
return FindPredicateDefinition(predicateStorage, null);
}
