be.SIRAPRISE.typeimplementations
Class EQ_BOOLEAN_BOOLEAN

java.lang.Object
  be.SIRAPRISE.typeimplementations.EQ_BOOLEAN_BOOLEAN

All Implemented Interfaces:

AggregationOperatorImplementation, BinaryBooleanOperatorImplementation, OperatorImplementation, OperatorImplementation_V0104

public final class EQ_BOOLEAN_BOOLEAN
extends java.lang.Object
implements AggregationOperatorImplementation, BinaryBooleanOperatorImplementation

Boolean equality differs from all other scalar equality operators in that it also happens to be associative. For all other types, the question of associativity does not pose itself because the return type boolean is not the same as the arguments For boolean, the return type happens to be the same, and furthermore we are unfortunate enough for the operator to be damn associative, which brings us in need of another interface to be implemented (b1 = b2) = b3 === b1 = (b2 = b3) (b1 & b2 | ^b1 & ^b2) = b3 === (b3 & b2 | ^b3 & ^b2) = b1 (b1 & b2 | ^b1 & ^b2) & b3 | ^(b1 & b2 | ^b1 & ^b2) & ^b3 === (b3 & b2 | ^b3 & ^b2) = b1 (b1 & b2 & b3 | ^b1 & ^b2 & b3) | (^(b1 & b2) & ^(^b1 & ^b2)) & ^b3 === (b3 & b2 | ^b3 & ^b2) = b1 (b1 & b2 & b3 | ^b1 & ^b2 & b3) | ((^b1 | ^b2) & (b1 | b2)) & ^b3 === (b3 & b2 | ^b3 & ^b2) = b1 (b1 & b2 & b3 | ^b1 & ^b2 & b3) | ((^b1 & b2) | (b1 & ^b2)) & ^b3 === (b3 & b2 | ^b3 & ^b2) = b1 (b1 & b2 & b3 | ^b1 & ^b2 & b3) | ((^b1 & b2) & ^b3 | (b1 & ^b2) & ^b3) === (b3 & b2 | ^b3 & ^b2) = b1 (b1 & b2 & b3 | ^b1 & ^b2 & b3) | ^b1 & b2 & ^b3 | b1 & ^b2 & ^b3 === (b3 & b2 | ^b3 & ^b2) = b1 ...

Author:

Erwin Smout

Method Summary

ValueBuffer	executeOperator(java.util.LinkedList<ValueBuffer> args) Performs the actual logic of the operator.
java.lang.String[]	getArgumentTypeNames() Gets the list of names of types of the needed argument values
ScalarValueBuffer	getIdentityElement() Gets the identity element of the operator in its domain.
static EQ_BOOLEAN_BOOLEAN	getInstance()
java.lang.String	getNegated(java.lang.String operand1, java.lang.String operand2) Gets the expression that is the negation of an invocation of this operator implementation
java.lang.String	getReturnTypeName() Gets the name of the type of the return value
boolean	isDeterministic() Tells whether the operator is deterministic with respect to the arguments of its invocations.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static EQ_BOOLEAN_BOOLEAN getInstance()

Returns:

the instance of the implementation

executeOperator

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

Description copied from interface: OperatorImplementation

Performs the actual logic of the operator.

Specified by:

executeOperator in interface OperatorImplementation

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.

Returns:

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

getArgumentTypeNames

public java.lang.String[] getArgumentTypeNames()

Description copied from interface: OperatorImplementation

Gets the list of names of types of the needed argument values

Specified by:

getArgumentTypeNames in interface OperatorImplementation

Returns:

The names of the argument types

getIdentityElement

public ScalarValueBuffer getIdentityElement()

Description copied from interface: AggregationOperatorImplementation

Gets the identity element of the operator in its domain.

Specified by:

getIdentityElement in interface AggregationOperatorImplementation

Returns:

The identity element.

getNegated

public java.lang.String getNegated(java.lang.String operand1,
                                   java.lang.String operand2)

Description copied from interface: BinaryBooleanOperatorImplementation

Gets the expression that is the negation of an invocation of this operator implementation

Specified by:

getNegated in interface BinaryBooleanOperatorImplementation

Parameters:

operand1 - The first operand of the invocation to be negated

operand2 - The second operand of the invocation to be negated

Returns:

the expression that is the negation of an invocation of this operator implementation

getReturnTypeName

public java.lang.String getReturnTypeName()

Description copied from interface: OperatorImplementation

Gets the name of the type of the return value

Specified by:

getReturnTypeName in interface OperatorImplementation

Returns:

the name of the type of the return value

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.