/// <summary>
/// Split on a specific node. This gets a type and splits it into
/// two subtypes.
/// </summary>
/// <param name="nodesInType"></param>
/// <param name="typeParents"></param>
/// <param name="node"></param>
/// <returns></returns>
public static SublatticeModification <T> SplitOn <T>(HashSet <LatticeNode <T> > nodesInType, HashSet <LatticeNode <T> > typeParents, LatticeNode <T> node)
{
//Debug.Assert(typeParents.Except(nodesInType).Count() == 0);
HashSet <LatticeNode <T> > transitiveClosuresForNewType = AbstractColoredLattice <T> .GetTransitiveChildrenClosure(nodesInType, node);
var modification = new SublatticeModification <T>()
{
Type = ModificationType.Split,
Data = node,
Before = new List <HashSet <LatticeNode <T> > >()
{
nodesInType
},
BeforeParent = new List <HashSet <LatticeNode <T> > >()
{
typeParents
},
After = new List <HashSet <LatticeNode <T> > >()
{
new HashSet <LatticeNode <T> >(nodesInType.Except(transitiveClosuresForNewType)),
new HashSet <LatticeNode <T> >(transitiveClosuresForNewType)
},
AfterParents = new List <HashSet <LatticeNode <T> > >()
{
new HashSet <LatticeNode <T> >(typeParents.Except(transitiveClosuresForNewType)),
new HashSet <LatticeNode <T> >(transitiveClosuresForNewType.Where(n => typeParents.Contains(n) || n.Parents.Any(p => !transitiveClosuresForNewType.Contains(p))).Concat(new List <LatticeNode <T> >()
{
node
}))
}
};
// Does this split a cycle?
var parentCluster = modification.After[0];
var childrenCluster = modification.After[1];
Debug.Assert(parentCluster.Intersect(childrenCluster).Count() == 0);
Debug.Assert(modification.AfterParents[0].Except(parentCluster).Count() == 0);
Debug.Assert(modification.AfterParents[1].Except(childrenCluster).Count() == 0);
var parClosure = AbstractColoredLattice <T> .GetTransitiveParentClosure(parentCluster);
parClosure.IntersectWith(childrenCluster);
if (parClosure.Count != 0)
{
return(null); // We are trying to split a circle
}
return(modification);
}
protected static void ApplyModification(List <HashSet <LatticeNode <TData> > > currentColoring, List <HashSet <LatticeNode <TData> > > currentColoringParents, SublatticeModification <TData> modification)
{
for (int i = 0; i < modification.After.Count; i++)
{
Debug.Assert(modification.AfterParents[i].Except(modification.After[i]).Count() == 0);
}
var removed = true;
foreach (var beforeType in modification.Before)
{
removed &= currentColoring.Remove(beforeType);
}
foreach (var beforeParents in modification.BeforeParent)
{
removed &= currentColoringParents.Remove(beforeParents);
}
Debug.Assert(removed);
currentColoring.AddRange(modification.After);
currentColoringParents.AddRange(modification.AfterParents);
}