be.SIRAPRISE.typeimplementations

Class IntervalMergesOperatorImplementation

java.lang.Object

be.SIRAPRISE.typeimplementations.IntervalMergesOperatorImplementation

All Implemented Interfaces:

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

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

IntervalMergesOperatorImplementation is the implementation class for the MERGES() operator for any interval type

Author:

Erwin Smout

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
IntervalMergesOperatorImplementation(java.lang.String intervalTypeName, IntervalOverlapsOperatorImplementation overlapsOperatorImplementation, IntervalMeetsOperatorImplementation meetsOperatorImplementation) Creates the IntervalMergesOperatorImplementation for the named interval type

Method Summary

Modifier and Type	Method and Description
ValueBuffer	executeOperator(java.util.LinkedList<ValueBuffer> args) The MERGES operator returns TRUE if the two interval arguments can be IUNIONed.
java.lang.String[]	getArgumentTypeNames() MERGES 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

IntervalMergesOperatorImplementation

public IntervalMergesOperatorImplementation(java.lang.String intervalTypeName,
                                            IntervalOverlapsOperatorImplementation overlapsOperatorImplementation,
                                            IntervalMeetsOperatorImplementation meetsOperatorImplementation)

Creates the IntervalMergesOperatorImplementation for the named interval type

Parameters:

intervalTypeName - The name of the interval type for which the MERGES operator is being defined

overlapsOperatorImplementation - The implementation object of the OVERLAPS operator for the interval type

meetsOperatorImplementation - The implementation object of the MEETS operator for the interval type

Method Detail

executeOperator

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

The MERGES operator returns TRUE if the two interval arguments can be IUNIONed. MERGES(i1,i2) is shorthand for MEETS(i1,i2) OR OVERLAPS(i1,i2). (Which is the precondition for IUNION to not raise an exception.)

truth table

Cases	(meaning)	MERGES operator outcome
Any argument is o (the empty interval)	b1 == e1 || b2 == e2	TRUE
Allen's MEETS operator	e1 == b2	TRUE
Allen's IS MET BY operator	e2 == b1	TRUE
Allen's OVERLAPS operator	b1 < b2 < e1	TRUE
Allen's IS OVERLAPPED BY operator	b2 < b1 < e2	TRUE
Allen's STARTS operator	b1 == b2 && e1 < e2	TRUE
Allen's IS STARTED BY operator	b1 == b2 && e1 > e2	TRUE
Allen's FINISHES operator	b1 > b2 && e1 == e2	TRUE
Allen's IS FINISHED BY operator	b1 < b2 && e1 == e2	TRUE
Allen's IS CONTAINED IN operator	b1 > b2 && e1 < e2	TRUE
Allen's CONTAINS operator	b1 < b2 && e1 > e2	TRUE
Allen's EQUALS operator	b1 == b2 && e1 == e2	TRUE
All other Allen operators (AFTER BEFORE)		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()

MERGES 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,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.io.IOException

java.lang.ClassNotFoundException

writeExternal

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

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException