//public bool HasNext()
//{
// if (c == null) // the first call of hasNext should find the first response
// Find();
// return c != null;
//}
//public Unifier Next()
//{
// if (c == null) Find();
// Unifier b = c;
// Find(); // find next response
// return b;
//}
void Find()
{
while (listOutter != null && listOutter.Count != 0)
{
while (list.Count != 0)
{
IListTerm candidate = AsSyntax.AsSyntax.CreateList(list);
list.Remove(list.ElementAt(list.Count - 1));
c = un.Clone();
if (c.UnifiesNoUndo(sublist, candidate))
{
return; // found another sublist, c is the current response
}
}
listOutter = listOutter.GetNext();
if (listOutter == null || listOutter.IsVar()) // the case of lists with tail
{
break;
}
list = listOutter.GetAsList();
}
if (!triedEmpty)
{
triedEmpty = true;
c = un.Clone();
if (c.UnifiesNoUndo(sublist, AsSyntax.AsSyntax.CreateList()))
{
return; // found another sublist, c is the current response
}
}
c = null; // no more sublists found
}
public SubListStdLibIterator(Reasoner ts, Unifier un, ITerm[] args, ITerm sublist)
{
this.ts = ts;
this.un = un;
this.args = args;
this.sublist = sublist;
this.c = null;
listOutter = (IListTerm)args[1];
list = listOutter.GetAsList();
triedEmpty = false;
}
