Package net.sf.saxon.expr

Class ValueComparison.ValueComparisonElaborator

java.lang.Object

net.sf.saxon.expr.elab.Elaborator

net.sf.saxon.expr.elab.ItemElaborator

net.sf.saxon.expr.ValueComparison.ValueComparisonElaborator

Enclosing class:

ValueComparison

public static class ValueComparison.ValueComparisonElaborator
extends ItemElaborator

Elaborator for a value comparison (such as A eq B), including the case where a general comparison is reduced to a value comparison by the optimiser

Constructor Summary

Constructors

Constructor	Description
ValueComparisonElaborator()

Method Summary

Modifier and Type	Method	Description
BooleanEvaluator	elaborateForBoolean()	Get a function that evaluates the underlying expression in the form of a boolean, this being the effective boolean value of the expression.
ItemEvaluator	elaborateForItem()	Get a function that evaluates the underlying expression in the form of a Item.

Methods inherited from class net.sf.saxon.expr.elab.ItemElaborator

eagerly, elaborateForPull, elaborateForPush, elaborateForUnicodeString

Methods inherited from class net.sf.saxon.expr.elab.Elaborator

elaborateForString, elaborateForUpdate, getConfiguration, getExpression, handleNullString, handleNullUnicodeString, handlePossiblyNullString, handlePossiblyNullUnicodeString, lazily, setExpression

Methods inherited from class java.lang.Object

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

Constructor Details

ValueComparisonElaborator

public ValueComparisonElaborator()

Method Details

elaborateForItem

public ItemEvaluator elaborateForItem()

Description copied from class: Elaborator

Get a function that evaluates the underlying expression in the form of a Item. This must only be called for expressions whose result has cardinality zero or one.

Specified by:

elaborateForItem in class ItemElaborator

Returns:

an evaluator for the expression that returns an Item, or null to represent an empty sequence.

elaborateForBoolean

public BooleanEvaluator elaborateForBoolean()

Description copied from class: Elaborator

Get a function that evaluates the underlying expression in the form of a boolean, this being the effective boolean value of the expression.

Overrides:

elaborateForBoolean in class ItemElaborator

Returns:

an evaluator for the expression that returns a boolean.