org.cryptimeleon.math.structures.groups.sn

Class Sn.SnElementImpl

java.lang.Object

org.cryptimeleon.math.structures.groups.sn.Sn.SnElementImpl

All Implemented Interfaces:

java.util.function.Function<java.lang.Integer,java.lang.Integer>, UniqueByteRepresentable, Representable, GroupElementImpl

Enclosing class:

Sn

public class Sn.SnElementImpl
extends java.lang.Object
implements GroupElementImpl, java.util.function.Function<java.lang.Integer,java.lang.Integer>

A permutation on \(\{1,...,n\}\).

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	images Contains the images of this permutation in order.

Constructor Summary

Constructors

Constructor and Description
SnElementImpl(java.util.function.Function<java.lang.Integer,java.lang.Integer> permutation) Create from a mapping.
SnElementImpl(int[] images) Create from a list of images, which contains the images of this permutation in order.
SnElementImpl(Representation repr) Recreate from representation.

Method Summary

Modifier and Type	Method and Description
java.lang.Integer	apply(java.lang.Integer i)
boolean	checkValidElement() Checks that this claimed permutation is indeed bijective.
boolean	equals(java.lang.Object obj)
Representation	getRepresentation() The representation of this object.
GroupImpl	getStructure() Retrieves the group this element belongs to.
int	hashCode()
Sn.SnElementImpl	inv() Calculates the inverse of this group element.
Sn.SnElementImpl	op(GroupElementImpl e) Calculates the result of this op e.
java.lang.String	toString()
ByteAccumulator	updateAccumulator(ByteAccumulator accumulator) Updates the ByteAccumulator with the unique byte representation of this object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.cryptimeleon.math.structures.groups.GroupElementImpl

isNeutralElement, pow, square

Methods inherited from interface org.cryptimeleon.math.hash.UniqueByteRepresentable

getUniqueByteRepresentation

Methods inherited from interface java.util.function.Function

andThen, compose, identity

Field Detail

images

protected int[] images

Contains the images of this permutation in order. Specifically, images[i] = j is equivalent to i being mapped to j. Note that images[0] is unused as we map \(\{1,...,n\}\).

Constructor Detail

SnElementImpl

public SnElementImpl(Representation repr)

Recreate from representation.

SnElementImpl

public SnElementImpl(java.util.function.Function<java.lang.Integer,java.lang.Integer> permutation)

Create from a mapping.

SnElementImpl

public SnElementImpl(int[] images)

Create from a list of images, which contains the images of this permutation in order. Specifically, images[i] = j is equivalent to i being mapped to j. Note that images[0] is unused as we map \(\{1,...,n\}\).

Method Detail

checkValidElement

public boolean checkValidElement()

Checks that this claimed permutation is indeed bijective.

getRepresentation

public Representation getRepresentation()

Description copied from interface: Representable

The representation of this object. Used for serialization. A convenient way to implement this is using @link ReprUtil

Specified by:

getRepresentation in interface Representable

Returns:

a Representation or null if an equal object can be recreated without any information.

See Also:

Representation

getStructure

public GroupImpl getStructure()

Description copied from interface: GroupElementImpl

Retrieves the group this element belongs to.

Specified by:

getStructure in interface GroupElementImpl

inv

public Sn.SnElementImpl inv()

Description copied from interface: GroupElementImpl

Calculates the inverse of this group element.

Specified by:

inv in interface GroupElementImpl

Returns:

an element x such that x.op(this).equals(getStructure().getNeutralElement())

op

public Sn.SnElementImpl op(GroupElementImpl e)
                    throws java.lang.IllegalArgumentException

Description copied from interface: GroupElementImpl

Calculates the result of this op e.

Specified by:

op in interface GroupElementImpl

Parameters:

e - right hand side of the operation

Returns:

the element resulting from the group operation

Throws:

java.lang.IllegalArgumentException - if e is of the wrong type

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

apply

public java.lang.Integer apply(java.lang.Integer i)

Specified by:

apply in interface java.util.function.Function<java.lang.Integer,java.lang.Integer>

updateAccumulator

public ByteAccumulator updateAccumulator(ByteAccumulator accumulator)

Description copied from interface: UniqueByteRepresentable

Updates the ByteAccumulator with the unique byte representation of this object.

The input to the accumulators update function is an injective (with respect to a given domain) byte encoding of this object.

For many use-cases, the AnnotatedUbrUtil can be used to quickly implement this method.

Specified by:

updateAccumulator in interface UniqueByteRepresentable

Returns:

the same accumulator as was input