// If nfa1 has form s1s ----> s1e
// then nfa0 has form s0s ----> s0s
// s0s -eps-> s1s
// s1e -eps-> s0s
public override Nfa MkNfa(Nfa.NameSource names)
{
Nfa nfa1 = r.MkNfa(names);
int s0s = names.next();
Nfa nfa0 = new Nfa(s0s, s0s);
foreach (KeyValuePair <int, ArrayList <Transition> > entry in nfa1.Trans)
{
nfa0.AddTrans(entry);
}
nfa0.AddTrans(s0s, null, nfa1.Start);
nfa0.AddTrans(nfa1.Exit, null, s0s);
return(nfa0);
}
// If nfa1 has form s1s ----> s1e
// and nfa2 has form s2s ----> s2e
// then nfa0 has form s1s ----> s1e -eps-> s2s ----> s2e
public override Nfa MkNfa(Nfa.NameSource names)
{
Nfa nfa1 = r1.MkNfa(names);
Nfa nfa2 = r2.MkNfa(names);
Nfa nfa0 = new Nfa(nfa1.Start, nfa2.Exit);
foreach (KeyValuePair <int, ArrayList <Transition> > entry in nfa1.Trans)
{
nfa0.AddTrans(entry);
}
foreach (KeyValuePair <int, ArrayList <Transition> > entry in nfa2.Trans)
{
nfa0.AddTrans(entry);
}
nfa0.AddTrans(nfa1.Exit, null, nfa2.Start);
return(nfa0);
}
// If nfa1 has form s1s ----> s1e
// and nfa2 has form s2s ----> s2e
// then nfa0 has form s0s -eps-> s1s ----> s1e -eps-> s0e
// s0s -eps-> s2s ----> s2e -eps-> s0e
public override Nfa MakeNfa(Nfa.NameSource names)
{
var s0s = names.next();
var s0e = names.next();
var nfa0 = new Nfa(s0s, s0e);
foreach (var regularExpression in _regularExpressions)
{
var nfa1 = regularExpression.MakeNfa(names);
foreach (var entry in nfa1.Trans)
{
nfa0.AddTrans(entry);
}
nfa0.AddTrans(s0s, null, nfa1.Start);
nfa0.AddTrans(nfa1.Exit, null, s0e);
}
return(nfa0);
}
abstract public Nfa MkNfa(Nfa.NameSource names);
