org.semanticweb.elk.util.collections.entryset

Interface StructuralObject

All Known Subinterfaces:

Entry<N>, GenericStructuralObject<T>

public interface StructuralObject

An object that can be structurally compared to other objects. Structural equality structuralEquals(Object) complements the object equality Object.equals(Object), and can be used to identify not necessarily equal objects that consist of (structurally) equal parts. This is in a similar way that Object.equals(Object) complements ==. The main purpose is to use an additional comparison functions (which is not used in standard collections) to identify structurally equal objects, which can be used, for example, for memoization. Unlike Object.equals(Object), the method structuralEquals(Object) does not return a boolean but either the input object, if the equality holds, or null if it does not hold. As for the object equality, structural equality must be symmetric and transitive. The structural equality must extend equality in the same way as Object.equals(Object) extends ==. That is, any two equal structural objects must be structurally equal. In addition to structural equality, there is also a structural hash code structuralHashCode() that is similar to the object hash code Object.hashCode(). As usual, the structural hash code must be compatible with structural equality, that is, if two object are structurally equal, they must have the same hash code.

Author:

Yevgeny Kazakov

Method Summary

Modifier and Type	Method and Description
StructuralObject	structuralEquals(Object other) Performs the structural equality comparison of this object with the given object.
int	structuralHashCode() Computes the structural hash code of this object, which is an integer uniquely determined by the structure of this object.

Method Detail

structuralEquals

StructuralObject structuralEquals(Object other)

Performs the structural equality comparison of this object with the given object. If the equality holds, then the input object must be also a StructuralObject, and it is returned in the output.

Parameters:

other - the object with which the comparison is performed

Returns:

the object if the structural equality test holds, or null if the structural equality test does not hold

See Also:

Object.equals(Object)

structuralHashCode

int structuralHashCode()

Computes the structural hash code of this object, which is an integer uniquely determined by the structure of this object. The same integer value should be returned for any two structurally equal objects (in terms of structuralEquals(Object).

Returns:

a number that is uniquely determined by the structure of this object.

See Also:

Object.hashCode()