Mercurial > pub > ImplabNet

comparison Implab/Automaton/RegularExpressions/Token.cs @ 162:0526412bbb26 ref20160224

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DFA refactoring
author cin
date Wed, 24 Feb 2016 08:39:53 +0300
parents
children e227e78d72e4
comparison
equal deleted inserted replaced
161:2a8466f0cb8a 162:0526412bbb26
1 using Implab;
2 using System;
3 using System.Linq;
4
5 namespace Implab.Automaton.RegularExpressions {
6 public abstract class Token<TTag> {
7 public abstract void Accept(IVisitor<TTag> visitor);
8
9 public Token<TTag> Extend() {
10 return Cat(new EndToken<TTag>());
11 }
12
13 public Token<TTag> Tag<T>(T tag) where T : IConvertible {
14 return Cat(new EndToken<TTag>(tag));
15 }
16
17 public Token<TTag> Cat(Token<TTag> right) {
18 return new CatToken<TTag>(this, right);
19 }
20
21 public Token<TTag> Or(Token<TTag> right) {
22 return new AltToken<TTag>(this, right);
23 }
24
25 public Token<TTag> Optional() {
26 return Or(new EmptyToken<TTag>());
27 }
28
29 public Token<TTag> EClosure() {
30 return new StarToken<TTag>(this);
31 }
32
33 public Token<TTag> Closure() {
34 return Cat(new StarToken<TTag>(this));
35 }
36
37 public Token<TTag> Repeat(int count) {
38 Token<TTag> token = null;
39
40 for (int i = 0; i < count; i++)
41 token = token != null ? token.Cat(this) : this;
42 return token ?? new EmptyToken<TTag>();
43 }
44
45 public Token<TTag> Repeat(int min, int max) {
46 if (min > max || min < 1)
47 throw new ArgumentOutOfRangeException();
48 var token = Repeat(min);
49
50 for (int i = min; i < max; i++)
51 token = token.Cat( this.Optional() );
52 return token;
53 }
54
55 public static Token<TTag> New<T>(params T[] set) where T : struct, IConvertible {
56 Safe.ArgumentNotNull(set, "set");
57 Token<TTag> token = null;
58 foreach(var c in set.Distinct())
59 token = token == null ? new SymbolToken<TTag>(c) : token.Or(new SymbolToken<TTag>(c));
60 return token;
61 }
62 }
63 }