LookupTable.cs


0:	// LookupTable.cs
1:	// Copyright (c) 2000 Mike Krueger
2:	//
3:	// This program is free software; you can redistribute it and/or modify
4:	// it under the terms of the GNU General Public License as published by
5:	// the Free Software Foundation; either version 2 of the License, or
6:	// (at your option) any later version.
7:	//
8:	// This program is distributed in the hope that it will be useful,
9:	// but WITHOUT ANY WARRANTY; without even the implied warranty of
10:	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11:	// GNU General Public License for more details.
12:	//
13:	// You should have received a copy of the GNU General Public License
14:	// along with this program; if not, write to the Free Software
15:	// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16:
17:	using System;
18:	using System.Collections;
19:	using System.Drawing;
20:
21:	namespace SharpDevelop.Internal.Text {
22:
23:	/// <summary>
24:	/// This class implements a keyword map. It implements a digital search trees (tries) to find
25:	/// a word.
26:	/// </summary>
27:	public class LookupTable
28:	{
29:	Node root = new Node(null, null);
30:	bool casesensitive;
31:
32:	/// <summary>
33:	/// Get the object, which was inserted under the keyword (line, at offset, with length length),
34:	/// returns null, if no such keyword was inserted.
35:	/// </summary>
36:	public object this[string line, int offset, int length] {
37:	get {
38:	if(length == 0)
39:	return null;
40:
41:	Node next = root;
42:	if (casesensitive) {
43:	for (int i = 0; i < length; ++i) {
44:	int index = ((int)line[offset + i]) % 256;
45:	next = next.leaf[index];
46:
47:	if (next == null) {
48:	return null;
49:	}
50:
51:	if (next.color != null && SharpDevelop.Tool.Text.TextUtility.RegionMatches(line, offset, length, next.word)) {
52:	return next.color;
53:	}
54:	}
55:	} else {
56:	for (int i = 0; i < length; ++i) {
57:	int index = ((int)Char.ToUpper(line[offset + i])) % 256;
58:	next = next.leaf[index];
59:
60:	if (next == null) {
61:	return null;
62:	}
63:	if (next.color != null && SharpDevelop.Tool.Text.TextUtility.RegionMatches(casesensitive, line, offset, length, next.word)) {
64:	return next.color;
65:	}
66:	}
67:	}
68:	return null;
69:	}
70:	}
71:
72:	/// <summary>
73:	/// Inserts an object in the tree, under keyword
74:	/// </summary>
75:	public object this[string keyword] {
76:	set {
77:	Node node = root;
78:	Node next = root;
79:	if (!casesensitive)
80:	keyword = keyword.ToUpper();
81:
82:	// insert word into the tree
83:	for (int i = 0; i < keyword.Length; ++i) {
84:	int index = ((int)keyword[i]) % 256; // index of curchar
85:	bool d = keyword[i] == '\\';
86:
87:	next = next.leaf[index]; // get node to this index
88:
89:	if (next == null) { // no node created -> insert word here
90:	node.leaf[index] = new Node(value, keyword);
91:	break;
92:	}
93:
94:	if (next.word != null && next.word.Length != i) { // node there, take node content and insert them again
95:	string tmpword = next.word; // this word will be inserted 1 level deeper (better, don't need too much
96:	object tmpcolor = next.color; // string comparisons for finding.)
97:	next.color = next.word = null;
98:	this[tmpword] = tmpcolor;
99:	}
100:
101:	if (i == keyword.Length - 1) { // end of keyword reached, insert node there, if a node was here it was
102:	next.word = keyword; // reinserted, if it has the same length (keyword EQUALS this word) it will be overwritten
103:	next.color = value;
104:	break;
105:	}
106:
107:	node = next;
108:	}
109:	}
110:	}
111:
112:	public LookupTable(bool casesensitive)
113:	{
114:	this.casesensitive = casesensitive;
115:	}
116:
117:	class Node
118:	{
119:	public Node(object color, string word)
120:	{
121:	this.word = word;
122:	this.color = color;
123:	}
124:
125:	public string word;
126:	public object color;
127:
128:	public Node[] leaf = new Node[256];
129:	}
130:	}
131:	}