1 | /* This file is part of the project "Hilbert II" - http://www.qedeq.org |
2 | * |
3 | * Copyright 2000-2014, Michael Meyling <mime@qedeq.org>. |
4 | * |
5 | * "Hilbert II" is free software; you can redistribute |
6 | * it and/or modify it under the terms of the GNU General Public |
7 | * License as published by the Free Software Foundation; either |
8 | * version 2 of the License, or (at your option) any later version. |
9 | * |
10 | * This program is distributed in the hope that it will be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13 | * GNU General Public License for more details. |
14 | */ |
15 | |
16 | package org.qedeq.kernel.bo.parser; |
17 | |
18 | import java.util.ArrayList; |
19 | import java.util.List; |
20 | |
21 | import org.qedeq.base.trace.Trace; |
22 | |
23 | /* |
24 | * LATER mime 20080131: refactor |
25 | * |
26 | */ |
27 | |
28 | /** |
29 | * Parse term or formula data into {@link org.qedeq.kernel.bo.parser.Term}s. |
30 | * This parser uses simple ASCII text operators. |
31 | * |
32 | * @author Michael Meyling |
33 | */ |
34 | public final class AsciiMathParser extends MathParser { |
35 | |
36 | /** This class. */ |
37 | private static final Class CLASS = AsciiMathParser.class; |
38 | |
39 | /** Separators for tokens. */ |
40 | private static final String SEPARATORS = "()[],{}"; |
41 | |
42 | /** |
43 | * Constructor. |
44 | */ |
45 | public AsciiMathParser() { |
46 | super(); |
47 | } |
48 | |
49 | protected final String readToken() { |
50 | final String method = "readToken()"; |
51 | int lines = 0; |
52 | while (getChar() != -1 && Character.isWhitespace((char) getChar())) { |
53 | if ('\n' == (char) getChar()) { |
54 | lines++; |
55 | } |
56 | readChar(); |
57 | } |
58 | if (lines > 1) { |
59 | return ""; |
60 | } |
61 | if (eof()) { |
62 | return null; |
63 | } |
64 | if (SEPARATORS.indexOf(getChar()) >= 0) { |
65 | Trace.param(CLASS, this, method, "Read token", "" + (char) getChar()); |
66 | return "" + (char) readChar(); |
67 | } |
68 | final StringBuffer token = new StringBuffer(); |
69 | String operator = null; |
70 | markPosition(); |
71 | while (!eof() && !Character.isWhitespace((char) getChar()) |
72 | && SEPARATORS.indexOf(getChar()) < 0) { |
73 | token.append((char) readChar()); |
74 | if (null != getOperator(token.toString())) { |
75 | operator = token.toString(); |
76 | clearMark(); |
77 | markPosition(); |
78 | } |
79 | } |
80 | if (operator != null) { |
81 | rewindPosition(); |
82 | token.setLength(0); |
83 | token.append(operator); |
84 | } else { |
85 | clearMark(); |
86 | } |
87 | Trace.param(CLASS, this, method, "Read token", token); |
88 | return token.toString(); |
89 | } |
90 | |
91 | protected final Operator getOperator(final String token) { |
92 | Operator result = null; |
93 | if (token == null) { |
94 | return result; |
95 | } |
96 | for (int i = 0; i < getOperators().size(); i++) { |
97 | if (token.equals(((Operator) getOperators().get(i)).getStartSymbol())) { |
98 | result = (Operator) getOperators().get(i); |
99 | break; |
100 | } |
101 | } |
102 | return result; |
103 | } |
104 | |
105 | protected final List getOperators(final String token) { |
106 | final List result = new ArrayList(); |
107 | if (token == null) { |
108 | return result; |
109 | } |
110 | for (int i = 0; i < getOperators().size(); i++) { |
111 | if (token.equals(((Operator) getOperators().get(i)).getStartSymbol())) { |
112 | result.add(getOperators().get(i)); |
113 | } |
114 | } |
115 | return result; |
116 | } |
117 | |
118 | protected boolean eot(final String token) { |
119 | return token == null || token.trim().length() == 0; |
120 | } |
121 | |
122 | } |