org.aitools.programd.util
Class PatternArbiter

java.lang.Object
  org.aitools.programd.util.PatternArbiter

public class PatternArbiter
extends Object

Provides utility methods for pattern-oriented tasks.

Since:

4.1.3

Author:

Noel Bush

Constructor Summary

PatternArbiter()

Method Summary

static void	checkAIMLPattern(String pattern) Determines whether a given string is a valid AIML pattern.
static Pattern	compile(String pattern, boolean ignoreCase) Translates the given AIML pattern to a regular expression and compiles it into a Pattern object.
static String	genericallyNormalize(String string) Applies a generic set of normalizations to an input, to prepare it for pattern matching.
static void	main(String[] args) For testing.
static boolean	matches(String literal, String pattern, boolean ignoreCase) Decides whether a given pattern matches a given literal, in an isolated context, according to the AIML pattern-matching specification.

Methods inherited from class java.lang.Object

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

Constructor Detail

PatternArbiter

public PatternArbiter()

Method Detail

genericallyNormalize

public static String genericallyNormalize(String string)

Applies a generic set of normalizations to an input, to prepare it for pattern matching.

Parameters:

string - the input to normalize

Returns:

the normalized input

compile

public static Pattern compile(String pattern,
                              boolean ignoreCase)
                       throws NotAnAIMLPatternException

Translates the given AIML pattern to a regular expression and compiles it into a Pattern object. Useful if you need to do a ton of tests with a pattern.

Parameters:

pattern - the pattern to compile

ignoreCase - whether to ignore case in matching

Returns:

the compiled pattern (translated to regex)

Throws:

NotAnAIMLPatternException - if the pattern is not a valid AIML pattern (conditioned by ignoreCase

matches

public static boolean matches(String literal,
                              String pattern,
                              boolean ignoreCase)
                       throws NotAnAIMLPatternException

Decides whether a given pattern matches a given literal, in an isolated context, according to the AIML pattern-matching specification. Indicates whether the given literal is matched by the given pattern. Note that the mechanism here is very simple: the AIML pattern is converted into an equivalent regular expression, and a match test is performed. This appears to be much more reliable than an old method that "manually" checked the match. This method uses a generic normalization that removes all punctuation from the input.

Parameters:

literal - the literal string to check

pattern - the pattern to try to match against it

ignoreCase - whether or not to ignore case

Returns:

true if pattern matches literal,false if not

Throws:

NotAnAIMLPatternException - if the pattern is not a valid AIML pattern (conditioned by ignoreCase

checkAIMLPattern

public static void checkAIMLPattern(String pattern)
                             throws NotAnAIMLPatternException

Determines whether a given string is a valid AIML pattern.

Parameters:

pattern - the string to check

Throws:

NotAnAIMLPatternException - with a helpful message if the pattern is not valid

main

public static void main(String[] args)

For testing.

Parameters:

args - not used