1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.regexp;
19
20 import org.apache.regexp.RECompiler;
21 import org.apache.regexp.RESyntaxException;
22
23 /**
24 * 'recompile' is a command line tool that pre-compiles one or more regular expressions
25 * for use with the regular expression matcher class 'RE'. For example, the command
26 * <code>java org.apache.regexp.recompile re1 "a*b"</code> produces output like this:
27 *
28 * <pre>
29 *
30 * // Pre-compiled regular expression 'a*b'
31 * private static final char[] re1Instructions =
32 * {
33 * 0x002a, 0x0000, 0x0007, 0x0041, 0x0001, 0xfffd, 0x0061,
34 * 0x0041, 0x0001, 0x0004, 0x0062, 0x0045, 0x0000, 0x0000,
35 * };
36 *
37 * private static final REProgram re1 = new REProgram(re1Instructions);
38 *
39 * </pre>
40 *
41 * By pasting this output into your code, you can construct a regular expression matcher
42 * (RE) object directly from the pre-compiled data (the character array re1), thus avoiding
43 * the overhead of compiling the expression at runtime. For example:
44 *
45 * <pre>
46 *
47 * RE r = new RE(re1);
48 *
49 * </pre>
50 *
51 * @see RE
52 * @see RECompiler
53 *
54 * @author <a href="mailto:jonl@muppetlabs.com">Jonathan Locke</a>
55 * @version $Id: recompile.java 518156 2007-03-14 14:31:26Z vgritsenko $
56 */
57 public class recompile
58 {
59 /**
60 * Main application entrypoint.
61 *
62 * @param arg Command line arguments
63 */
64 static public void main(String[] arg)
65 {
66 // Create a compiler object
67 RECompiler r = new RECompiler();
68
69 // Print usage if arguments are incorrect
70 if (arg.length <= 0 || arg.length % 2 != 0)
71 {
72 System.out.println("Usage: recompile <patternname> <pattern>");
73 System.exit(0);
74 }
75
76 // Loop through arguments, compiling each
77 for (int i = 0; i < arg.length; i += 2)
78 {
79 try
80 {
81 // Compile regular expression
82 String name = arg[i];
83 String pattern = arg[i+1];
84 String instructions = name + "Instructions";
85
86 // Output program as a nice, formatted character array
87 System.out.print("\n // Pre-compiled regular expression '" + pattern + "'\n"
88 + " private static final char[] " + instructions + " = \n {");
89
90 // Compile program for pattern
91 REProgram program = r.compile(pattern);
92
93 // Number of columns in output
94 int numColumns = 7;
95
96 // Loop through program
97 char[] p = program.getInstructions();
98 for (int j = 0; j < p.length; j++)
99 {
100 // End of column?
101 if ((j % numColumns) == 0)
102 {
103 System.out.print("\n ");
104 }
105
106 // Print character as padded hex number
107 String hex = Integer.toHexString(p[j]);
108 while (hex.length() < 4)
109 {
110 hex = "0" + hex;
111 }
112 System.out.print("0x" + hex + ", ");
113 }
114
115 // End of program block
116 System.out.println("\n };");
117 System.out.println("\n private static final REProgram " + name + " = new REProgram(" + instructions + ");");
118 }
119 catch (RESyntaxException e)
120 {
121 System.out.println("Syntax error in expression \"" + arg[i] + "\": " + e.toString());
122 }
123 catch (Exception e)
124 {
125 System.out.println("Unexpected exception: " + e.toString());
126 }
127 catch (Error e)
128 {
129 System.out.println("Internal error: " + e.toString());
130 }
131 }
132 }
133 }
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