tom.library.sl
Class Choice

java.lang.Object
  tom.library.sl.AbstractStrategy
      tom.library.sl.Choice

All Implemented Interfaces:

Strategy, Visitable

public class Choice
extends AbstractStrategy

Choice(v1,v2) = v1 if v1 succeeds

Choice(v1,v2) = v2 if v1 fails

Visitor combinator with two visitor arguments, that tries to apply the first visitor and if it fails tries the other (left-biased choice).

Note that any side-effects of v1 are not undone when it fails.

Field Summary

static int	FIRST
static int	THEN

Fields inherited from class tom.library.sl.AbstractStrategy

environment, visitors

Constructor Summary

Choice(Strategy first, Strategy then)

Method Summary

int	visit() Visits the current subject (found in the environment) and place its result in the environment.
Visitable	visitLight(Visitable visitable) Visits the subject any in a light way (without environment)

Methods inherited from class tom.library.sl.AbstractStrategy

accept, getChildAt, getChildCount, getChildren, getEnvironment, getRoot, getSubject, init, init, initSubterm, initSubterm, initSubterm, initSubterm, initSubterm, setChildAt, setChildren, setEnvironment, setRoot, setSubject, visit, visit

Methods inherited from class java.lang.Object

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

Field Detail

FIRST

public static final int FIRST

See Also:

Constant Field Values

THEN

public static final int THEN

See Also:

Constant Field Values

Constructor Detail

Choice

public Choice(Strategy first,
              Strategy then)

Method Detail

visitLight

public Visitable visitLight(Visitable visitable)
                     throws VisitFailure

Description copied from interface: Strategy

Visits the subject any in a light way (without environment)

Parameters:

visitable - the subject to visit.

Throws:

VisitFailure - in case of failure.

visit

public int visit()

Description copied from interface: Strategy

Visits the current subject (found in the environment) and place its result in the environment. Sets the environment flag to Environment.FAILURE in case of failure