de.uka.ilkd.key.strategy.termfeature

Class ShannonTermFeature

java.lang.Object

de.uka.ilkd.key.strategy.termfeature.ShannonTermFeature

All Implemented Interfaces:

TermFeature

public class ShannonTermFeature
extends java.lang.Object
implements TermFeature

A conditional feature, in which the condition itself is a (binary) feature. The general notion is a term c ? f1 : f2, whereby the condition c determines whether the value of the whole expression is f1 (if c returns zero, or more general if c returns a distinguished value trueCost) or f2

Field Summary

Fields

Modifier and Type	Field and Description
private TermFeature	cond The filter that decides which sub-feature is to be evaluated
private TermFeature	elseFeature The feature for negative results of filter
private TermFeature	thenFeature The feature for positive results of filter
private RuleAppCost	trueCost If the result of cond is this cost, then the condition is assumed to hold

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ShannonTermFeature(TermFeature p_cond, RuleAppCost p_trueCost, TermFeature p_thenFeature, TermFeature p_elseFeature)

Method Summary

Modifier and Type	Method and Description
RuleAppCost	compute(Term term, Services services)
static TermFeature	createConditionalBinary(TermFeature cond, TermFeature thenFeature)
static TermFeature	createConditionalBinary(TermFeature cond, TermFeature thenFeature, TermFeature elseFeature)

Methods inherited from class java.lang.Object

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

Field Detail

cond

private final TermFeature cond

The filter that decides which sub-feature is to be evaluated

trueCost

private final RuleAppCost trueCost

If the result of cond is this cost, then the condition is assumed to hold

thenFeature

private final TermFeature thenFeature

The feature for positive results of filter

elseFeature

private final TermFeature elseFeature

The feature for negative results of filter

Constructor Detail

ShannonTermFeature

private ShannonTermFeature(TermFeature p_cond,
                           RuleAppCost p_trueCost,
                           TermFeature p_thenFeature,
                           TermFeature p_elseFeature)

Method Detail

compute

public RuleAppCost compute(Term term,
                           Services services)

Specified by:

compute in interface TermFeature

createConditionalBinary

public static TermFeature createConditionalBinary(TermFeature cond,
                                                  TermFeature thenFeature,
                                                  TermFeature elseFeature)

Parameters:

cond - the feature that decides which value is to be returned

thenFeature - the value of the feature if cond returns zero

elseFeature - the value of the feature if cond does not return zero

Returns:

the value of thenFeature if cond returns zero, the value of elseFeature otherwise

createConditionalBinary

public static TermFeature createConditionalBinary(TermFeature cond,
                                                  TermFeature thenFeature)

Parameters:

cond - the feature that decides which value is to be returned

thenFeature - the value of the feature if cond returns zero

Returns:

the value of thenFeature if cond returns zero, zero otherwise