public static IEnumerable<State> AStar()
{
var aAlternation = new Alternation();
State a = new State("A", aAlternation);
aAlternation.Alternations.Add(new Concat(new PushState(a), new RegexLiteral("a")));
aAlternation.Alternations.Add(new RegexLiteral(""));
return new[] { a };
}
public static IEnumerable<State> AnBn()
{
State b = new State("B", new RegexLiteral("b"));
var aAlternation = new Alternation();
State a = new State("A", aAlternation);
aAlternation.Alternations.Add(new Concat(new PushState(b), new RegexLiteral("a"), new PushState(a)));
aAlternation.Alternations.Add(new RegexLiteral(""));
return new[] { a, b };
}
public static void AnBmCnm()
{
State c = new State("C", new RegexLiteral("c"));
var bAlternation=new Alternation();
State b = new State("B", bAlternation);
bAlternation.Alternations.Add(new Concat(new PushState(c), new RegexLiteral("b"), new PushState(b)));
bAlternation.Alternations.Add(new RegexLiteral(""));
var aAlternation=new Alternation();
State a = new State("A", aAlternation);
}
private void Write(Alternation alternation)
{
if (alternation.Alternations.Count == 1)
{
Write(alternation.Alternations.Single());
return;
}
using (NonCapturingGroup())
{
WriteWithSeparator("|", alternation.Alternations);
}
}
public static IEnumerable<State> NumberedStatesPcreGrammarStates()
{
var q0Altermations = new Alternation(new RegexLiteral(@"\w"));
State q = new State("Q", q0Altermations);
//// A -> A (',' | Q) | ε
var a0Altermations = new Alternation();
State a = new State("A", a0Altermations);
a0Altermations.Alternations.Add(new Concat(new PushState(a), new Alternation(new RegexLiteral(","), new PushState(q))));
a0Altermations.Alternations.Add(new RegexLiteral(""));
// pop Q2Close -> '>'
State q2Close = new State("Q2Close", new RegexLiteral(">"));
State q2 = new State("Q2", new Concat(new RegexLiteral("<"),
new PushState(q2Close),
new PushState(a)));
q0Altermations.Alternations.Add(q2.StateBody);
// pop QStar -> push QStar push Q | ε
State qStar = GetStateStar(q);
State q1Close = new State("Q1Close", new RegexLiteral(@"\]"));
// pop Q2Semicolon -> ';'
State q1Semicolon = new State("Q1Semicolon", new RegexLiteral(";"));
//pop Q2OptionalComma -> ',' | ε
State q1OptionalComma = new State("Q1Comma", new RegexLiteral(",?"));
//pop Q1 -> '[' push Q1Close push QStar push Q1OptionalComma push QStar push Q1Semicolon push A
State q1 = new State("Q1", new Concat(
new RegexLiteral(@"\["),
new PushState(q1Close),
new PushState(qStar),
new PushState(q1OptionalComma),
new PushState(qStar),
new PushState(q1Semicolon),
new PushState(a)
));
q0Altermations.Alternations.Add(q1.StateBody);
return new[] { a, q, q2Close, qStar, q1OptionalComma, q1Semicolon, q1Close };
}
/*
A -> (Q | ',')*
Q -> \w | '[' A ';' Q* ','? Q* ']' | '<' A '>'
\__________Q1___________/ \__Q2___/
========================================
pop A -> push A (',' | Q) | ε
pop Q -> \w | push Q1 | push Q2
pop QStar -> push QStar push Q | ε
pop Q2 -> '<' push Q2Close push A
pop Q2Close -> '>'
pop Q1 -> '[' push Q1Close push QStar push Q1OptionalComma push QStar push Q1Semicolon push A
pop Q1Close -> ']'
pop Q2Semicolon -> ';'
pop Q2OptionalComma -> ',' | ε
*/
/// <summary>
/// For a State "X", generate a new State classed "XStar" representing "X*".
/// </summary>
private static State GetStateStar(State state)
{
var starAlternations = new Alternation();
State stateStar = new State(state.Name + "Star", starAlternations);
starAlternations.Alternations.Add(new Concat(new PushState(stateStar), new PushState(state)));
starAlternations.Alternations.Add(new RegexLiteral(""));
return stateStar;
}
public static IEnumerable<State> NumberedStatesPcreGrammarWithCapturesStates()
{
var q0Altermations = new Alternation(new RegexLiteral(@"\w(?<Q-Start>)"));
State q = new State("Q", new Concat(new RegexLiteral(@"(?<Start>)"), q0Altermations));
var a0 = new State("A0", new Alternation(new RegexLiteral(","), new PushState(q)));
var a0Star = GetStateStar(a0);
var aEnd = new State("AEnd", new RegexLiteral("(?<A-Start>)"));
var a = new State("A", new Concat(new RegexLiteral(@"(?<Start>)") ,new PushState(aEnd),new PushState(a0Star)));
// pop Q2Close -> '>'
State q2Close = new State("Q2Close", new RegexLiteral(">(?<Q-Start>)"));
State q2 = new State("Q2", new Concat(new RegexLiteral("<"),
new PushState(q2Close),
new PushState(a)));
q0Altermations.Alternations.Add(q2.StateBody);
// pop QStar -> push QStar push Q | ε
State qStar = GetStateStar(q);
State q1Close = new State("Q1Close", new RegexLiteral(@"\](?<Q-Start>)"));
// pop Q2Semicolon -> ';'
State q1Semicolon = new State("Q1Semicolon", new RegexLiteral(";"));
//pop Q2OptionalComma -> ',' | ε
State q1OptionalComma = new State("Q1Comma", new RegexLiteral(",?"));
//pop Q1 -> '[' push Q1Close push QStar push Q1OptionalComma push QStar push Q1Semicolon push A
State q1 = new State("Q1", new Concat(
new RegexLiteral(@"\["),
new PushState(q1Close),
new PushState(qStar),
new PushState(q1OptionalComma),
new PushState(qStar),
new PushState(q1Semicolon),
new PushState(a)
));
q0Altermations.Alternations.Add(q1.StateBody);
return new[] { a, a0, a0Star,aEnd, q, q2Close, qStar, q1OptionalComma, q1Semicolon, q1Close };
}