1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
<html><!-- #BeginTemplate "/Templates/maintemplate.dwt" -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<!-- #BeginEditable "doctitle" -->
<title>JEP - Java Math Expression Parser</title>
<!-- #EndEditable -->
<link rel="stylesheet" type="text/css" href="main.css" title="style1">
</head>
<body>
<!-- NAVIGATION ---------------------------------------------------- -->
<div id="navcontainer">
<ul>
<li><a href="../javadoc/index.html" target="_blank">JavaDoc <img src="img/new-window-icon.gif" width="15" height="11"></a></li>
</ul>
<h1>JEP</h1>
<ul>
<li><a href="index.html">Basic Usage</a></li>
<li><a href="variables.html">Variables</a></li>
<li><a href="types.html">Data types</a></li>
<li><a href="operators.html">Operators</a></li>
<li><a href="functions.html">Functions</a></li>
<li><a href="advanced.html">Advanced Features</a></li>
<li><a href="grammar.html">Grammar</a></li>
<li><a href="faq.html">FAQ</a></li>
<li><a href="version.html">Version History</a></li>
</ul>
<h1>Extensions</h1>
<ul>
<li><a href="extensions/index.html">Overview</a></li>
<li><a href="extensions/xjep.html">XJep</a></li>
<li><a href="extensions/djep.html">Differentiation</a></li>
<li><a href="extensions/vectorjep.html">Vectors and Matrices</a></li>
<li><a href="extensions/groupjep.html">Groups</a></li>
<li><a href="extensions/version.html">Version History</a></li>
</ul>
</div>
<div id="centercontent">
<!-- CENTER CONTENT -------------------------------------------------- -->
<!-- #BeginEditable "Text" -->
<h1><a name="top"></a>Operators</h1>
<h2>Built in operators</h2>
<p>All common arithmetic operators are supported. Boolean operators are also
fully supported. Boolean expressions are evaluated to be either 1 or 0 (true
or false respectively).</p>
<p>An <img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check">
indicates that the operator can be used with the specific type of variable.
Refer to the <a href="grammar.html">grammar</a> for detailed information about
operator precedence.</p>
<table border="0" cellspacing="1" cellpadding="2" width="100%" bgcolor="#CCCCCC">
<tr bgcolor="#FFFFFF">
<td width="225"> </td>
<td width="91"> </td>
<td width="76"><b>Double</b></td>
<td width="81"><b>Complex</b></td>
<td width="91"><b>String</b></td>
<td width="91"><b>Vector</b></td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Power</td>
<td width="91">^</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="91" align="center"> </td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Boolean Not</td>
<td width="91">!</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"> </td>
<td width="91" align="center"> </td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Unary Plus, Unary Minus</td>
<td width="91">+x, -x</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="91" align="center"> </td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Modulus</td>
<td width="91">%</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"> </td>
<td width="91" align="center"> </td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Division</td>
<td width="91">/</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="91" align="center"> </td>
<td width="91" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Multiplication</td>
<td width="91">*</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="91" align="center"> </td>
<td width="91" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Addition, Subtraction</td>
<td width="91">+, -</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="91" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check">
(only +)</td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Less or Equal, More or Equal</td>
<td width="91" bordercolor="#CCCCCC"><=, >=</td>
<td width="76" bordercolor="#CCCCCC" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" bordercolor="#CCCCCC" align="center"> </td>
<td width="91" bordercolor="#CCCCCC" align="center"> </td>
<td width="91" bordercolor="#CCCCCC" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Less Than, Greater Than</td>
<td width="91"><, ></td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"> </td>
<td width="91" align="center"> </td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Not Equal, Equal</td>
<td width="91">!=, ==</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="91" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Boolean And</td>
<td width="91">&&</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"> </td>
<td width="91" align="center"> </td>
<td width="91" align="center"> </td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="225">Boolean Or</td>
<td width="91">||</td>
<td width="76" align="center"><img src="img/checkmark.gif" width="10" height="10" border="0" alt="Check"></td>
<td width="81" align="center"> </td>
<td width="91" align="center"> </td>
<td width="91" align="center"> </td>
</tr>
</table>
<!-- #BeginLibraryItem "/Library/top bar.lbi" -->
<div class="topbar"><a href="#top"><img src="img/top.gif" width="38" height="15" name="top"></a></div>
<!-- #EndLibraryItem -->
<h2>Adding operators</h2>
<p>Adding operators is currently only possible by modifying the JEP source code.
To add an operator to the parser several steps are needed:
<ul>
<li>Create a new <i>token</i> with the descriptive name AT, say, and a string
representing the operator. </li>
<li>Modify the grammer rules to include a rule for the new operator </li>
<li>Create a new object implementing org.nfunk.jep.function.PostfixMathCommandI
to provide methods for evaluating the operator. </li>
<li>Modify or sub class org.nfunk.jep.OperatorSet to bind the operator in
the parser to PostfixMathCommand </li>
</ul>
Before atempting to add an operator you should be familiar with adding a <a href="functions.html#custom">custom
function</a> to JEP.
<h3>JavaCC The parser generator</h3>
<p> Rather than writing the parser by hand in java the parser is created using
the <a href="https://javacc.dev.java.net/">JavaCC</a> parser/scanner generator.
This reads a file Parser.jjt which is written in a special language which
defines the grammer and creates Parser.java and some other java files which
implement the parser.</p>
<p>You should read some of the documentation on <a href="https://javacc.dev.java.net/doc/docindex.html/">JavaCC</a>
and <a href="https://javacc.dev.java.net/doc/JJTree.html">JJTree</a> before
attempting to modify the parser.</p>
<p>There is a three step process used to generate the parser. </p>
<ol>
<li>JJTree is run. This reads the file Parser.jjt and creates a file Parser.jj.
The purpose of this step is to add code needed to handle Abstract Systax
Trees which are tree structures used represent a mathematical expression.
As well as creating parser.jj it also creates some other java files: Node.java
which represents the basic node in the parser; ASTConstant.java a node representing
a constant value "0" or "1", ASTVarNode.java a node representing a variable,
ASTFunNode.java a node representing a function or operator.
<li>javacc is run. This reads Parser.jj and creates Parser.java the actual
code for implementing the Parser. Parser.java is a very complicated file
with nearly 2000 lines of code.
<li>Normal java comilation step which compiles Parser.java.
</ol>
<p> This process should automatically be caried out when the project is built
using the ANT build.xml file. It is not sufficient to simple recompile all
the java files.</p>
<p>Only the Parser.jjt file should be modified, Parser.jj, Parser.java should
not be modified as they will be overwritten during the build process. Furthermore
ASTConstant.java, ASTFunNode.java, ASTStart.java, ASTVarNode.java, JavaCharStream.java,
JJTParserState.java, Node.java, SimpleNode.java, ParseException.java, ParserConstants.java,
ParserTokenManager.java, ParseTreeConstants.java, Token.java, TokenMgrError.java
should not normally be modified as these are also automatically generated.</p>
<!-- #BeginLibraryItem "/Library/top bar.lbi" -->
<div class="topbar"><a href="#top"><img src="img/top.gif" width="38" height="15" name="top"></a></div>
<!-- #EndLibraryItem -->
<!-- #EndEditable -->
<!-- FOOTER ---------------------------------------------------------- -->
<div id="footer">
<a href="http://sourceforge.net/tracker/?func=add&group_id=24711&atid=382402">Report bugs / documentation errors</a><br/>
<br/>
© 2006 <a href="http://www.singularsys.com" target="_blank">Singular Systems</a>
</div>
</div> <!-- centercontent -->
</body>
<!-- #EndTemplate --></html>
|
