/*
* Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.sun.org.apache.regexp.internal;
import com.sun.org.apache.regexp.internal.RECompiler;
import com.sun.org.apache.regexp.internal.RESyntaxException;
/**
* 'recompile' is a command line tool that pre-compiles one or more regular expressions
* for use with the regular expression matcher class 'RE'. For example, the command
* "java recompile a*b" produces output like this:
*
* <pre>
*
* // Pre-compiled regular expression "a*b"
* char[] re1Instructions =
* {
* 0x007c, 0x0000, 0x001a, 0x007c, 0x0000, 0x000d, 0x0041,
* 0x0001, 0x0004, 0x0061, 0x007c, 0x0000, 0x0003, 0x0047,
* 0x0000, 0xfff6, 0x007c, 0x0000, 0x0003, 0x004e, 0x0000,
* 0x0003, 0x0041, 0x0001, 0x0004, 0x0062, 0x0045, 0x0000,
* 0x0000,
* };
*
* REProgram re1 = new REProgram(re1Instructions);
*
* </pre>
*
* By pasting this output into your code, you can construct a regular expression matcher
* (RE) object directly from the pre-compiled data (the character array re1), thus avoiding
* the overhead of compiling the expression at runtime. For example:
*
* <pre>
*
* RE r = new RE(re1);
*
* </pre>
*
* @see RE
* @see RECompiler
*
* @author <a href="mailto:jonl@muppetlabs.com">Jonathan Locke</a>
*/
public class recompile
{
/**
* Main application entrypoint.
* @param arg Command line arguments
*/
static public void main(String[] arg)
{
// Create a compiler object
RECompiler r = new RECompiler();
// Print usage if arguments are incorrect
if (arg.length <= 0 || arg.length % 2 != 0)
{
System.out.println("Usage: recompile <patternname> <pattern>");
System.exit(0);
}
// Loop through arguments, compiling each
for (int i = 0; i < arg.length; i += 2)
{
try
{
// Compile regular expression
String name = arg[i];
String pattern = arg[i+1];
String instructions = name + "PatternInstructions";
// Output program as a nice, formatted character array
System.out.print("\n // Pre-compiled regular expression '" + pattern + "'\n"
+ " private static char[] " + instructions + " = \n {");
// Compile program for pattern
REProgram program = r.compile(pattern);
// Number of columns in output
int numColumns = 7;
// Loop through program
char[] p = program.getInstructions();
for (int j = 0; j < p.length; j++)
{
// End of column?
if ((j % numColumns) == 0)
{
System.out.print("\n ");
}
// Print character as padded hex number
String hex = Integer.toHexString(p[j]);
while (hex.length() < 4)
{
hex = "0" + hex;
}
System.out.print("0x" + hex + ", ");
}
// End of program block
System.out.println("\n };");
System.out.println("\n private static RE " + name + "Pattern = new RE(new REProgram(" + instructions + "));");
}
catch (RESyntaxException e)
{
System.out.println("Syntax error in expression \"" + arg[i] + "\": " + e.toString());
}
catch (Exception e)
{
System.out.println("Unexpected exception: " + e.toString());
}
catch (Error e)
{
System.out.println("Internal error: " + e.toString());
}
}
}
}