//tested
public RegularExpression Union(RegularExpression right)
{
var left = this;
NFAModel model = new NFAModel();
NFAState s = new NFAState(0);
model.entryEdge = new NFAEdge(s, 0);
s.AddEdge(left.nfa.entryEdge);
s.AddEdge(right.nfa.entryEdge);
model.tailState = new NFAState();
left.nfa.tailState.AddEdgeTo(model.tailState);
right.nfa.tailState.AddEdgeTo(model.tailState);
nfa = model;
return(this);
}
//basisOp
//tested
public RegularExpression DefineLiteral(string input)
{
NFAModel model = new NFAModel();
NFAState s = new NFAState(0);
model.entryEdge = new NFAEdge(s, 0);
for (int i = 0; i < input.Length; i++)
{
NFAState state = new NFAState(i + 1);
s.AddEdge(new NFAEdge(state, input[i]));
s = state;
}
model.tailState = new NFAState(s.id + 1);
s.AddEdgeTo(model.tailState);
nfa = model;
return(this);
}
//can only contain value
//97-122,65-90,48-57
//a-z，A-Z，1-9
public static RegularExpression DefineRange(char x, char y)
{
if (x > y)
{
var t = x;
x = y;
y = x;
}
RegularExpression r = new RegularExpression();
var model = r.nfa = new NFAModel();
NFAState s = new NFAState(0);
model.tailState = new NFAState(1);
model.entryEdge = new NFAEdge(s);
for (int i = x; i <= y; i++)
{
s.AddEdge(new NFAEdge(model.tailState, i));
}
return(r);
}
//Todo: need faster
public void CreateDFAModel()
{
var finalNFA = new NFAModel();
var tmpState = new NFAState(0);
finalNFA.entryEdge = new NFAEdge(tmpState);
var index = 1;
foreach (var regex in regexCollection)
{
var x = regex.NFAModel;
tmpState.AddEdge(x.entryEdge);
index = x.RenameStates(index);
}
//make first dfaset
DFAState first = new DFAState(tmpState);
int id = 0;
first.Id = id++;
DFAList.Add(first);
for (int i = 0; i < DFAList.Count; i++)
{
var list = new List <int>();
//possible move
foreach (var x in DFAList[i].Edges)
{
if (!list.Contains(x.statement))
{
list.Add(x.statement);
}
}
foreach (var x in list)
{
var lead = DFAList[i].E_closure(x);
var have = false;
foreach (var u in DFAList)
{
if (u.isEqual(lead))
{
DFAList[i].LeadTo(u, x);
have = true;
break;
}
}
if (have)
{
continue;
}
lead.Id = id++;
DFAList[i].LeadTo(lead, x);
DFAList.Add(lead);
}
}
//change priority here
for (int i = regexCollection.Count - 1; i >= 0; i--)
{
var op = regexCollection[i];
var nfa = op.NFAModel;
foreach (var x in DFAList)
{
if (x.Contains(nfa.tailState))
{
x.isEndState = true;
x.describtion = op.Describtion;
x.index = op.Index;
}
}
}
}