be.SIRAPRISE.typeimplementations

Class IntervalBeginsOperatorImplementation

java.lang.Object

be.SIRAPRISE.typeimplementations.IntervalBeginsOperatorImplementation

All Implemented Interfaces:

IntervalOperatorImplementation, OperatorImplementation_V0104, OperatorImplementation_V0105, java.io.Externalizable, java.io.Serializable

public final class IntervalBeginsOperatorImplementation
extends java.lang.Object
implements IntervalOperatorImplementation

The implementation object for a particular IntervalBegins operator

Author:

Erwin Smout

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
IntervalBeginsOperatorImplementation(IntervalTypeImplementation intervalTypeImplementation) Creates the intervalbegins operator implementation object for some specific ordered base type.

Method Summary

Modifier and Type	Method and Description
ValueBuffer	executeOperator(java.util.LinkedList<ValueBuffer> args) The BEGINS operator returns TRUE if both interval arguments have an equal begin point, and the end point of the former is not after that of the second.
java.lang.String[]	getArgumentTypeNames() BEGINS takes two arguments that are both of the same interval type
TypeDeclaration	getReturnTypeDeclaration() Gets the full type declaration of the type of the return value.
java.lang.String	getReturnTypeName() The return type is BOOLEAN
java.lang.String	getSignature() Gets the name of the operator implemented by this implementation object
boolean	isDeterministic() Tells whether the operator is deterministic with respect to the arguments of its invocations.
void	readExternal(java.io.ObjectInput in)
void	writeExternal(java.io.ObjectOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

IntervalBeginsOperatorImplementation

public IntervalBeginsOperatorImplementation(IntervalTypeImplementation intervalTypeImplementation)

Creates the intervalbegins operator implementation object for some specific ordered base type.

Parameters:

intervalTypeImplementation - the underlying base type's maximum size

Method Detail

executeOperator

public ValueBuffer executeOperator(java.util.LinkedList<ValueBuffer> args)

The BEGINS operator returns TRUE if both interval arguments have an equal begin point, and the end point of the former is not after that of the second.

truth table

Cases	(meaning)	BEGINS operator outcome
Any argument is o (the empty interval)	b1 == e1 || b2 == e2	FALSE
Allen's STARTS operator	b1 == b2 && e1 < e2	TRUE
Allen's EQUALS operator	b1 == b2 && e1 == e2	TRUE
All other Allen operators		FALSE

Specified by:

executeOperator in interface OperatorImplementation_V0104

Parameters:

args - the argument list. The list must hold as many ValueBuffer objects as there are arguments to the operator, and each ValueBuffer object holds a value for some argument to the operator. ValueBuffer objects on the list must appear in the same order as the operator argument declarations. Implementations have the option, but are not required, to do a check the conformance of the argument list (the argument count, notably) to the operator signature.

Returns:

A ValueBuffer object holding the result value of the operator execution in internal format.

getArgumentTypeNames

public java.lang.String[] getArgumentTypeNames()

BEGINS takes two arguments that are both of the same interval type

Specified by:

getArgumentTypeNames in interface OperatorImplementation_V0104

Returns:

The names of the argument types

getReturnTypeDeclaration

public TypeDeclaration getReturnTypeDeclaration()

Description copied from interface: OperatorImplementation_V0105

Gets the full type declaration of the type of the return value. Differs from the _V0104 getReturnTypeName() in that for nonscalar return types, this method also returns the heading, not just only the RELATION or TUPLE typename.

Specified by:

getReturnTypeDeclaration in interface OperatorImplementation_V0105

Returns:

the full type declaration of the type of the return value

getReturnTypeName

public java.lang.String getReturnTypeName()

The return type is BOOLEAN

Specified by:

getReturnTypeName in interface OperatorImplementation_V0104

Returns:

the name of the type of the return value

getSignature

public java.lang.String getSignature()

Description copied from interface: OperatorImplementation_V0104

Gets the name of the operator implemented by this implementation object

Specified by:

getSignature in interface OperatorImplementation_V0104

Returns:

the name of the operator implemented by this implementation object

isDeterministic

public boolean isDeterministic()

Description copied from interface: OperatorImplementation_V0104

Tells whether the operator is deterministic with respect to the arguments of its invocations. An operator is deterministic if and only if for any two distinct invocations, if all the argument values are the same, then the result value returned will also be the same. An example of a nondeterministic operators is RANDOM().

Specified by:

isDeterministic in interface OperatorImplementation_V0104

Returns:

true if the operator is deterministic.

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.io.IOException

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException