internal CodePredicate Add(Functor functor, CodePredicateDelegate codePredicateDelegate)
{
if (functor == null)
{
throw new ArgumentNullException("functor");
}
if (codePredicateDelegate == null)
{
throw new ArgumentNullException("codePredicateDelegate");
}
if (Contains(functor))
{
throw new ArgumentException("Item already exists.", "functor");
}
CodePredicate predicate = new CodePredicate(this, functor, codePredicateDelegate);
Items.Add(predicate);
Library.Touch();
return(predicate);
}
private ExecutionResults OnLibraryCallCodePredicate(WamInstruction instruction, CodePredicate predicate)
{
WamReferenceTarget[] arguments = new WamReferenceTarget[instruction.Functor.Arity];
for (int index = 0; index < instruction.Functor.Arity; ++index)
{
arguments[index] = ArgumentRegisters[index];
}
try
{
predicate.CodePredicateDelegate(this, arguments);
}
catch
{
// Backtrack on exception.
//
return ExecutionResults.Backtrack;
}
return ExecutionResults.None;
}