org.metasyntactic.math.automata
Class RegularExpressionFactory

java.lang.Object
  |
  +--org.metasyntactic.math.automata.RegularExpressionFactory

public class RegularExpressionFactory

extends java.lang.Object

A factory class for returning any of the 3 regular expression atoms. Also includes a wicked cool method for returning a regular expression object encoded in a string.

Method Summary

static RegularExpression	empty()
static RegularExpression	fromString(java.lang.String s)
static RegularExpression	fromString(java.lang.String s, boolean largeIdentifiers) Given any RegularExpression R, Let S = R.toString().
static void	main(java.lang.String[] args)
static RegularExpression	Null()
static RegularExpression	symbol(char c)
static RegularExpression	symbol(java.lang.Object o)

Methods inherited from class java.lang.Object

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

Method Detail

empty

public static RegularExpression empty()

Null

public static RegularExpression Null()

symbol

public static RegularExpression symbol(java.lang.Object o)

symbol

public static RegularExpression symbol(char c)

fromString

public static RegularExpression fromString(java.lang.String s)
                                    throws ParseException

ParseException

fromString

public static RegularExpression fromString(java.lang.String s,
                                           boolean largeIdentifiers)
                                    throws ParseException

Given any RegularExpression R, Let S = R.toString(). The contract of this method is that R.equals(fromString(S)) should always be true. Thus this method reverses the actions of toString(), reconstructing the RegularExpression Object that created the string.

However, due to the way regular expressions can be printed, there are configurbale options. Consider the regexp "abcd". This could represent the regular expression object "(((ab)c)d)", or it could represent the regular expression object "(abcd)". Either are acceptable interpretations. largeIdentifiers is used to determine the behavior of the matching.

ParseException

main

public static void main(java.lang.String[] args)
                 throws java.lang.Throwable

java.lang.Throwable