/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 me.regexp;
import java.io.PrintStream;
import java.util.Hashtable;
/**
* A subclass of RECompiler which can dump a regular expression program
* for debugging purposes.
*
* @author <a href="mailto:jonl@muppetlabs.com">Jonathan Locke</a>
*/
public class REDebugCompiler extends RECompiler
{
/**
* Mapping from opcodes to descriptive strings
*/
static Hashtable hashOpcode = new Hashtable();
static
{
hashOpcode.put(new Integer(RE.OP_RELUCTANTSTAR), "OP_RELUCTANTSTAR");
hashOpcode.put(new Integer(RE.OP_RELUCTANTPLUS), "OP_RELUCTANTPLUS");
hashOpcode.put(new Integer(RE.OP_RELUCTANTMAYBE), "OP_RELUCTANTMAYBE");
hashOpcode.put(new Integer(RE.OP_END), "OP_END");
hashOpcode.put(new Integer(RE.OP_BOL), "OP_BOL");
hashOpcode.put(new Integer(RE.OP_EOL), "OP_EOL");
hashOpcode.put(new Integer(RE.OP_ANY), "OP_ANY");
hashOpcode.put(new Integer(RE.OP_ANYOF), "OP_ANYOF");
hashOpcode.put(new Integer(RE.OP_BRANCH), "OP_BRANCH");
hashOpcode.put(new Integer(RE.OP_ATOM), "OP_ATOM");
hashOpcode.put(new Integer(RE.OP_STAR), "OP_STAR");
hashOpcode.put(new Integer(RE.OP_PLUS), "OP_PLUS");
hashOpcode.put(new Integer(RE.OP_MAYBE), "OP_MAYBE");
hashOpcode.put(new Integer(RE.OP_NOTHING), "OP_NOTHING");
hashOpcode.put(new Integer(RE.OP_GOTO), "OP_GOTO");
hashOpcode.put(new Integer(RE.OP_CONTINUE), "OP_CONTINUE");
hashOpcode.put(new Integer(RE.OP_ESCAPE), "OP_ESCAPE");
hashOpcode.put(new Integer(RE.OP_OPEN), "OP_OPEN");
hashOpcode.put(new Integer(RE.OP_CLOSE), "OP_CLOSE");
hashOpcode.put(new Integer(RE.OP_BACKREF), "OP_BACKREF");
hashOpcode.put(new Integer(RE.OP_POSIXCLASS), "OP_POSIXCLASS");
hashOpcode.put(new Integer(RE.OP_OPEN_CLUSTER), "OP_OPEN_CLUSTER");
hashOpcode.put(new Integer(RE.OP_CLOSE_CLUSTER), "OP_CLOSE_CLUSTER");
}
/**
* Returns a descriptive string for an opcode.
*
* @param opcode Opcode to convert to a string
* @return Description of opcode
*/
String opcodeToString(char opcode)
{
// Get string for opcode
String ret = (String) hashOpcode.get(new Integer(opcode));
// Just in case we have a corrupt program
if (ret == null)
{
ret = "OP_????";
}
return ret;
}
/**
* Return a string describing a (possibly unprintable) character.
*
* @param c Character to convert to a printable representation
* @return String representation of character
*/
String charToString(char c)
{
// If it's unprintable, convert to '\###'
if (c < ' ' || c > 127)
{
return "\\" + (int) c;
}
// Return the character as a string
return String.valueOf(c);
}
/**
* Returns a descriptive string for a node in a regular expression program.
* @param node Node to describe
* @return Description of node
*/
String nodeToString(int node)
{
// Get opcode and opdata for node
char opcode = instruction[node /* + RE.offsetOpcode */];
int opdata = (int) instruction[node + RE.offsetOpdata ];
// Return opcode as a string and opdata value
return opcodeToString(opcode) + ", opdata = " + opdata;
}
/**
* Dumps the current program to a {@link PrintStream}.
*
* @param p PrintStream for program dump output
*/
public void dumpProgram(PrintStream p)
{
// Loop through the whole program
for (int i = 0; i < lenInstruction; )
{
// Get opcode, opdata and next fields of current program node
char opcode = instruction[i /* + RE.offsetOpcode */];
char opdata = instruction[i + RE.offsetOpdata ];
int next = (short) instruction[i + RE.offsetNext ];
// Display the current program node
p.print(i + ". " + nodeToString(i) + ", next = ");
// If there's no next, say 'none', otherwise give absolute index of next node
if (next == 0)
{
p.print("none");
}
else
{
p.print(i + next);
}
// Move past node
i += RE.nodeSize;
// If character class
if (opcode == RE.OP_ANYOF)
{
// Opening bracket for start of char class
p.print(", [");
// Show each range in the char class
// int rangeCount = opdata;
for (int r = 0; r < opdata; r++)
{
// Get first and last chars in range
char charFirst = instruction[i++];
char charLast = instruction[i++];
// Print range as X-Y, unless range encompasses only one char
if (charFirst == charLast)
{
p.print(charToString(charFirst));
}
else
{
p.print(charToString(charFirst) + "-" + charToString(charLast));
}
}
// Annotate the end of the char class
p.print("]");
}
// If atom
if (opcode == RE.OP_ATOM)
{
// Open quote
p.print(", \"");
// Print each character in the atom
for (int len = opdata; len-- != 0; )
{
p.print(charToString(instruction[i++]));
}
// Close quote
p.print("\"");
}
// Print a newline
p.println("");
}
}
/**
* Dumps the current program to a <code>System.out</code>.
*/
public void dumpProgram()
{
PrintStream w = new PrintStream(System.out);
dumpProgram(w);
w.flush();
}
}