internal CharacterSet/*!*/ Intersect(CharacterSet/*!*/ set) {
if (IsEmpty || set.IsEmpty) {
return Empty;
}
if (_negated) {
if (set._negated) {
// ^A and ^B == ^(A or B)
return Complement().Union(set.Complement()).Complement();
} else {
// ^A and B = B \ A
return set.Subtract(Complement());
}
} else if (set._negated) {
// A and ^B = A \ B
return Subtract(set.Complement());
}
// (a \ B) and (c \ D) == a \ ^(c \ (B or D))
//
// Proof:
// (a \ B) and (c \ D) ==
// (a and ^B) and (c and ^D) ==
// a \ ^(c and ^B and ^D) ==
// a \ ^(c \ (B or D)) QED
return new CharacterSet(_include, new CharacterSet(true, set._include, _exclude.Union(set._exclude)));
}
private int BuildDFAState(HashSet <int> nfaList)
{
NfaState state = new NfaState();
foreach (var num in nfaList)
{
state.NFAStates.UnionWith(m_nfa[num].NFAClosure);
}
int index = DFAStateNumber(state);
if (index == -1)
{
index = AddDFAState(state);
foreach (var num in state.NFAStates)
{
foreach (var item in m_nfa[num].AcceptList)
{
state.AcceptList.Add(item);
}
}
var set2 = new List <int>();
var list = new List <Edge>();
foreach (var num in state.NFAStates)
{
foreach (var edge in m_nfa[num].Edges)
{
list.Add(edge);
set2.Add(edge.Target);
}
}
if (set2.Count >= 1)
{
var buildArray = new List <CharacterSet>(set2.Count);
foreach (int target in set2)
{
var build = new CharacterSet();
foreach (var edge in list)
{
if (edge.Target == target)
{
build.Add(edge.Characters);
}
}
foreach (var edge in list)
{
if (edge.Target != target)
{
build.Subtract(edge.Characters);
}
}
buildArray.Add(build);
}
CharacterSet build5 = new CharacterSet();
foreach (var edge in list)
{
build5.Add(edge.Characters);
}
foreach (var set in buildArray)
{
build5.Subtract(set);
}
for (int i = 0; i < set2.Count; ++i)
{
if (buildArray[i].Count >= 1)
{
var setList = new HashSet <int> {
set2[i]
};
state.AddEdge(BuildDFAState(setList), buildArray[i]);
}
}
foreach (var number in build5)
{
var setList = new HashSet <int>();
foreach (var edge in list)
{
if (ReferenceEquals(edge.Characters, null))
{
continue;
}
if (edge.Characters.Contains(number))
{
setList.Add(edge.Target);
}
}
if (setList.Count > 0)
{
var build = new CharacterSet();
build.Add(number);
state.AddEdge(BuildDFAState(setList), build);
}
}
}
}
return(index);
}