public FindData[] Optimize(RuleTable rules, ConstraintSystem environment, CancellationToken cancel)
{
//// Step 1. Try to split the items into connected components.
var itemDats = new Map <Term, ItemData>(Term.Compare);
var useLists = new Map <Term, Set <ItemData> >(Term.Compare);
foreach (var kv in findPatterns)
{
itemDats.Add(kv.Key, RegisterUses(new ItemData(kv.Key, kv.Value.Item1), useLists));
}
foreach (var con in constraints)
{
itemDats.Add(con, RegisterUses(new ItemData(con), useLists));
}
FindData f1, f2;
Tuple <ItemData, LinkedList <ItemData> > partialRule;
var components = ComputeComponents(itemDats, useLists);
if (components.Length == 0)
{
return(new FindData[] { rules.CompilePartialRule(default(FindData), default(FindData), new Set <Term>(Term.Compare), environment) });
}
var outputs = new FindData[components.Length];
for (int i = 0; i < components.Length; ++i)
{
var ordering = OrderComponents(i, components[i], useLists);
Contract.Assert(ordering != null && ordering.Count > 0);
//// Debug_PrintOrderData(i, ordering);
//// Console.WriteLine();
using (var it = ordering.GetEnumerator())
{
it.MoveNext();
partialRule = it.Current;
if (partialRule.Item1 != null)
{
f1 = new FindData(partialRule.Item1.Item, findPatterns[partialRule.Item1.Item].Item1, findPatterns[partialRule.Item1.Item].Item2);
}
else
{
f1 = default(FindData);
}
var constrs = new Set <Term>(Term.Compare);
foreach (var c in partialRule.Item2)
{
constrs.Add(c.Item);
}
if (ordering.Count == 1)
{
outputs[i] = rules.CompilePartialRule(f1, default(FindData), constrs, environment);
continue;
}
while (it.MoveNext())
{
partialRule = it.Current;
if (constrs == null)
{
constrs = new Set <Term>(Term.Compare);
}
if (partialRule.Item1 != null)
{
f2 = new FindData(partialRule.Item1.Item, findPatterns[partialRule.Item1.Item].Item1, findPatterns[partialRule.Item1.Item].Item2);
}
else
{
f2 = default(FindData);
}
foreach (var c in partialRule.Item2)
{
constrs.Add(c.Item);
}
f1 = rules.CompilePartialRule(f1, f2, constrs, environment);
outputs[i] = f1;
constrs = null;
}
}
}
return(outputs);
}