Package org.variantsync.diffdetective.util.fide

Class FixTrueFalse

java.lang.Object

org.variantsync.diffdetective.util.fide.FixTrueFalse

public class FixTrueFalse
extends Object

Class to fix bugs related to True and False of FeatureIDE. See: FeatureIDE Issue 1111 See: FeatureIDE Issue 1333 This class contains constants for representing atomic values true and false in formulas as well as a conversion method for parsing certain feature names to true and false, respectively.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FixTrueFalse.Formula	This class is a witness that a formula had its true and false constants eliminated or is just such a constant (and nothing else except from perhaps negations).

Field Summary

Fields

Modifier and Type	Field	Description
static final org.prop4j.Literal	False	Constant literal representing false.
static final List<String>	FalseNames	Names of variables that we want to interpret as the constant false.
static final org.prop4j.Literal	True	Constant literal representing true.
static final List<String>	TrueNames	Names of variables that we want to interpret as the constant true.

Constructor Summary

Constructors

Constructor	Description
FixTrueFalse()

Method Summary

Modifier and Type	Method	Description
private static <T> boolean	contains(T[] ts, Predicate<T> elem)	Check if ts contains an element matching the predicate elem.
static FixTrueFalse.Formula	EliminateTrueAndFalse(org.prop4j.Node formula)	Replaces all literals in the given formula with the literals True and False.
static FixTrueFalse.Formula	EliminateTrueAndFalseInplace(org.prop4j.Node formula)	Same as EliminateTrueAndFalse(org.prop4j.Node) but mutates the given formula in-place.
private static org.prop4j.Node	EliminateTrueAndFalseInplaceRecurse(org.prop4j.Node formula)
private static org.prop4j.Node[]	filterMatches(org.prop4j.Node[] nodes, Predicate<org.prop4j.Node> filter)	Return a new array only containing elements of nodes for which the predicate filter returns false.
static boolean	isFalse(org.prop4j.Node f)	Returns true iff the given formula is a false literal.
static boolean	isFalseLiteral(String l)	Returns true iff the given name represents the atomic value false.
static boolean	isFalseLiteral(org.prop4j.Literal l)	Returns true iff the given literal's variable is the atomic value false.
static boolean	isTrue(org.prop4j.Node f)	Returns true iff the given formula is a true literal.
static boolean	isTrueLiteral(String l)	Returns true iff the given name represents the atomic value true.
static boolean	isTrueLiteral(org.prop4j.Literal l)	Returns true iff the given literal's variable is the atomic value true.

Methods inherited from class java.lang.Object

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

Field Details

TrueNames

public static final List<String> TrueNames

Names of variables that we want to interpret as the constant true.

FalseNames

public static final List<String> FalseNames

Names of variables that we want to interpret as the constant false.

True

public static final org.prop4j.Literal True

Constant literal representing true.

False

public static final org.prop4j.Literal False

Constant literal representing false.

Constructor Details

FixTrueFalse

public FixTrueFalse()

Method Details

isTrue

public static boolean isTrue(org.prop4j.Node f)

Returns true iff the given formula is a true literal.

See Also:

• isTrueLiteral(org.prop4j.Literal)

isFalse

public static boolean isFalse(org.prop4j.Node f)

Returns true iff the given formula is a false literal.

See Also:

• isFalseLiteral(org.prop4j.Literal)

isTrueLiteral

public static boolean isTrueLiteral(org.prop4j.Literal l)

Returns true iff the given literal's variable is the atomic value true.

See Also:

• TrueNames

isTrueLiteral

public static boolean isTrueLiteral(String l)

Returns true iff the given name represents the atomic value true.

See Also:

• TrueNames

isFalseLiteral

public static boolean isFalseLiteral(org.prop4j.Literal l)

Returns true iff the given literal's variable is the atomic value false.

See Also:

• FalseNames

isFalseLiteral

public static boolean isFalseLiteral(String l)

Returns true iff the given name represents the atomic value false.

See Also:

• TrueNames

filterMatches

private static org.prop4j.Node[] filterMatches(org.prop4j.Node[] nodes,
 Predicate<org.prop4j.Node> filter)

Return a new array only containing elements of nodes for which the predicate filter returns false.

contains

private static <T> boolean contains(T[] ts,
 Predicate<T> elem)

Check if ts contains an element matching the predicate elem.

EliminateTrueAndFalse

public static FixTrueFalse.Formula EliminateTrueAndFalse(org.prop4j.Node formula)

Replaces all literals in the given formula with the literals True and False. This includes replacing literals representing variables with names of constants with their actual constant, for example literals with a name contained in TrueNames by True. By applying constant folding the result will be either True, False, or a formula that does not contain any True or False nodes. For an impure, in-place version of this method (which is likely more performant) see EliminateTrueAndFalseInplace(org.prop4j.Node).

Parameters:

formula - the formula to simplify. It remains unchanged.

Returns:

either True, False, negations of the previous (i.e., in terms of Not or Literal), or a formula without True or False

EliminateTrueAndFalseInplace

public static FixTrueFalse.Formula EliminateTrueAndFalseInplace(org.prop4j.Node formula)

Same as EliminateTrueAndFalse(org.prop4j.Node) but mutates the given formula in-place. Thus, the given formula should not be used after invoking this method as it might be corrupted. Instead, the returned node should be used.

Parameters:

formula - the formula to transform

Returns:

either True, False, negations of the previous (i.e., in terms of Not or Literal), or a formula without True or False

See Also:

• EliminateTrueAndFalse(org.prop4j.Node)

EliminateTrueAndFalseInplaceRecurse

private static org.prop4j.Node EliminateTrueAndFalseInplaceRecurse(org.prop4j.Node formula)