pobs.parser
Class POptional

java.lang.Object
  pobs.PParser
      pobs.parser.POptional

All Implemented Interfaces:

PObject

public class POptional

extends PParser

Matches succesful always, the length of the match is zero when the specified parser fails or the length of the specified parsers' succesful match. BNF: this := parser?

Author:

Martijn W. van der Lee

Constructor Summary

POptional(PObject parser)
Sole constructor.

Method Summary

PMatch

parse(PScanner input, long begin, PContext context)

Methods inherited from class pobs.PParser

addControl, getErrorInfo, process, setErrorInfo, setMatchAction, setMismatchAction

Methods inherited from class java.lang.Object

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

Constructor Detail

POptional

public POptional(PObject parser)

Sole constructor.

Parameters:

parser - a parser

Method Detail

parse

public PMatch parse(PScanner input,
                    long begin,
                    PContext context)

Parameters:

input - Input to be parsed.

begin - Index of first character of input to be parsed.

context - Parsing context.

Returns:

Parsing result.