org.uacalc.alg.op
Class AbstractOperation

java.lang.Object
  org.uacalc.alg.op.AbstractOperation

All Implemented Interfaces:

Operation

Direct Known Subclasses:

OperationWithDefaultValue, TermOperationImp

public abstract class AbstractOperation
extends java.lang.Object
implements Operation

This class implements the basic methods of Operation. valueAt is abstract so must be overwritten.

Version:

$Id: AbstractOperation.java,v 1.7 2008/11/03 04:48:43 ralphfreese Exp $

Author:

Ralph Freese, Emil Kiss

Field Summary

protected int	algSize
protected OperationSymbol	symbol
protected int[]	valueTable

Constructor Summary

AbstractOperation(OperationSymbol symbol, int algSize)

AbstractOperation(java.lang.String name, int arity, int algSize)

Method Summary

int	arity() This gives the arity of this operation.
int	getSetSize() This gives the size of the set upon which the operation acts.
int[]	getTable() Get the table for this operation or null if it does not exist.
int[]	getTable(boolean makeTable) Get the table for this operation.
int	intValueAt(int arg) This (optional) operation is for fast access to the table, if it exits.
int	intValueAt(int[] args) This (optional) operation is the int version.
boolean	isAssociative() Test if this operation is binary and associative.
boolean	isCommutative() Test if this operation is binary and commutative.
boolean	isIdempotent() Is this operation idempotent in the sense f(x,x,..,x) = x.
boolean	isTableBased()
boolean	isTotal() Only OperationWithDefaultValue's can fail this.
boolean	isTotallySymmetric() Test if this operation is totally symmetric; that is, invariant under all permutation of the variables.
void	makeTable() This will make a table and so make the operation faster but requires more space.
OperationSymbol	symbol() The operation symbol for this operation.
int[]	valueAt(int[][] args) This operation is for fast product operation.
abstract java.lang.Object	valueAt(java.util.List args) This operation is the element version.

Methods inherited from class java.lang.Object

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

Field Detail

symbol

protected OperationSymbol symbol

algSize

protected int algSize

valueTable

protected int[] valueTable

Constructor Detail

AbstractOperation

public AbstractOperation(java.lang.String name,
                         int arity,
                         int algSize)

AbstractOperation

public AbstractOperation(OperationSymbol symbol,
                         int algSize)

Method Detail

arity

public int arity()

This gives the arity of this operation.

Specified by:

arity in interface Operation

getSetSize

public int getSetSize()

This gives the size of the set upon which the operation acts.

Specified by:

getSetSize in interface Operation

symbol

public OperationSymbol symbol()

Description copied from interface: Operation

The operation symbol for this operation.

Specified by:

symbol in interface Operation

valueAt

public abstract java.lang.Object valueAt(java.util.List args)

Description copied from interface: Operation

This operation is the element version.

Specified by:

valueAt in interface Operation

valueAt

public int[] valueAt(int[][] args)

Description copied from interface: Operation

This operation is for fast product operation.

Specified by:

valueAt in interface Operation

Parameters:

args - an array of arity int arrays from the product algebra.

intValueAt

public int intValueAt(int[] args)

Description copied from interface: Operation

This (optional) operation is the int version.

Specified by:

intValueAt in interface Operation

intValueAt

public int intValueAt(int arg)

Description copied from interface: Operation

This (optional) operation is for fast access to the table, if it exits.

Specified by:

intValueAt in interface Operation

Parameters:

arg - the Horner encoding of the actual args.

Returns:

isTableBased

public boolean isTableBased()

Specified by:

isTableBased in interface Operation

isIdempotent

public boolean isIdempotent()

Is this operation idempotent in the sense f(x,x,..,x) = x.

Specified by:

isIdempotent in interface Operation

isTotal

public boolean isTotal()

Description copied from interface: Operation

Only OperationWithDefaultValue's can fail this.

Specified by:

isTotal in interface Operation

Returns:

isTotallySymmetric

public boolean isTotallySymmetric()

Test if this operation is totally symmetric; that is, invariant under all permutation of the variables.

Specified by:

isTotallySymmetric in interface Operation

isAssociative

public boolean isAssociative()

Test if this operation is binary and associative.

Specified by:

isAssociative in interface Operation

isCommutative

public boolean isCommutative()

Test if this operation is binary and commutative.

Specified by:

isCommutative in interface Operation

makeTable

public void makeTable()

Description copied from interface: Operation

This will make a table and so make the operation faster but requires more space. So if A is in HSP(B) then for ints x and y, x * y would be evaluated by finding the representative of x and y of the congruence; then these representatives would be expanded into array representing the corresponding elements in the direct product. These would be multiplied and then the whole process would be reversed. If A is reasonable small it may make sense to make a table for the multiplication.

Specified by:

makeTable in interface Operation

getTable

public int[] getTable()

Description copied from interface: Operation

Get the table for this operation or null if it does not exist.

Specified by:

getTable in interface Operation

getTable

public int[] getTable(boolean makeTable)

Description copied from interface: Operation

Get the table for this operation. If it does not exist make it if makeTable is true.

Specified by:

getTable in interface Operation

Parameters:

makeTable - forces the table to be made if necessary

Returns:

the table