/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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());

            }

        }

    }

}