org.apache.regexp

Class REProgram

java.lang.Object

org.apache.regexp.REProgram

All Implemented Interfaces:

Serializable

public class REProgram
extends Object
implements Serializable

A class that holds compiled regular expressions. This is exposed mainly for use by the recompile utility (which helps you produce precompiled REProgram objects). You should not otherwise need to work directly with this class.

Version:

$Id: REProgram.java 518156 2007-03-14 14:31:26Z vgritsenko $

Author:

Jonathan Locke

See Also:

RE, RECompiler, Serialized Form

Constructor Summary

Constructors

Constructor and Description
REProgram(char[] instruction) Constructs a program object from a character array
REProgram(char[] instruction, int lenInstruction) Constructs a program object from a character array
REProgram(int parens, char[] instruction) Constructs a program object from a character array

Method Summary

Modifier and Type	Method and Description
char[]	getInstructions() Returns a copy of the current regular expression program in a character array that is exactly the right length to hold the program.
char[]	getPrefix() Returns a copy of the prefix of current regular expression program in a character array.
void	setInstructions(char[] instruction, int lenInstruction) Sets a new regular expression program to run.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

REProgram

public REProgram(char[] instruction)

Constructs a program object from a character array

Parameters:

instruction - Character array with RE opcode instructions in it

REProgram

public REProgram(char[] instruction,
                 int lenInstruction)

Constructs a program object from a character array

Parameters:

instruction - Character array with RE opcode instructions in it

lenInstruction - Amount of instruction array in use

REProgram

public REProgram(int parens,
                 char[] instruction)

Constructs a program object from a character array

Parameters:

parens - Count of parens in the program

instruction - Character array with RE opcode instructions in it

Method Detail

getInstructions

@Nullable
public char[] getInstructions()

Returns a copy of the current regular expression program in a character array that is exactly the right length to hold the program. If there is no program compiled yet, getInstructions() will return null.

Returns:

A copy of the current compiled RE program

getPrefix

@Nullable
public char[] getPrefix()

Returns a copy of the prefix of current regular expression program in a character array. If there is no prefix, or there is no program compiled yet, getPrefix will return null.

Returns:

A copy of the prefix of current compiled RE program

setInstructions

public void setInstructions(char[] instruction,
                            int lenInstruction)

Sets a new regular expression program to run. It is this method which performs any special compile-time search optimizations. Currently only two optimizations are in place - one which checks for backreferences (so that they can be lazily allocated) and another which attempts to find an prefix anchor string so that substantial amounts of input can potentially be skipped without running the actual program.

Parameters:

instruction - Program instruction buffer

lenInstruction - Length of instruction buffer in use