org.apache.regexp
Class REProgram

java.lang.Object
  |
  +--org.apache.regexp.REProgram
All Implemented Interfaces:
java.io.Serializable

public class REProgram
extends java.lang.Object
implements java.io.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

Field Summary
(package private)  int flags
           
(package private)  char[] instruction
           
(package private)  int lenInstruction
           
(package private)  int maxParens
           
(package private) static int OPT_HASBACKREFS
           
(package private) static int OPT_HASBOL
           
(package private)  char[] prefix
           
 
Constructor Summary
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
 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, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Field Detail

OPT_HASBACKREFS

static final int OPT_HASBACKREFS

OPT_HASBOL

static final int OPT_HASBOL

instruction

char[] instruction

lenInstruction

int lenInstruction

prefix

char[] prefix

flags

int flags

maxParens

int maxParens
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(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

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
Method Detail

getInstructions

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

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

getPrefix

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


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