Package net.sf.saxon.expr

Class LetExpression.LetExprElaborator

java.lang.Object

net.sf.saxon.expr.elab.Elaborator

net.sf.saxon.expr.elab.PullElaborator

net.sf.saxon.expr.LetExpression.LetExprElaborator

Enclosing class:

LetExpression

public static class LetExpression.LetExprElaborator
extends PullElaborator

Elaborator for a let expression (either let $x := SELECT return ACTION in XPath, or the equivalent sequence constructor using local xsl:variable declarations in XSLT).

The elaborator allows evaluation in pull, push, or singleton mode.

Constructor Summary

Constructors

Constructor	Description
LetExprElaborator()

Method Summary

Modifier and Type	Method	Description
SequenceEvaluator	eagerly()	Get a function that evaluates the underlying expression eagerly
ItemEvaluator	elaborateForItem()	Get a function that evaluates the underlying expression in the form of a Item.
PullEvaluator	elaborateForPull()	Get a function that evaluates the underlying expression in the form of a SequenceIterator
PushEvaluator	elaborateForPush()	Get a function that evaluates the underlying expression in push mode, by writing events to an Outputter
UpdateEvaluator	elaborateForUpdate()

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

elaborateForBoolean, elaborateForUnicodeString

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

elaborateForString, 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 Detail

LetExprElaborator

public LetExprElaborator()

Method Detail

eagerly

public SequenceEvaluator eagerly()

Description copied from class: Elaborator

Get a function that evaluates the underlying expression eagerly

Overrides:

eagerly in class PullElaborator

Returns:

an evaluator for the expression that returns a GroundedValue. The class SequenceEvaluator is declared to return a Sequence not a GroundedValue; we can't specialize it because it's a limitation of C# delegates, but the result can safely be cast to GroundedValue.

elaborateForPull

public PullEvaluator elaborateForPull()

Description copied from class: Elaborator

Get a function that evaluates the underlying expression in the form of a SequenceIterator

Specified by:

elaborateForPull in class PullElaborator

Returns:

an evaluator for the expression that returns a SequenceIterator

elaborateForPush

public PushEvaluator elaborateForPush()

Description copied from class: Elaborator

Get a function that evaluates the underlying expression in push mode, by writing events to an Outputter

Overrides:

elaborateForPush in class PullElaborator

Returns:

an evaluator for the expression in push mode

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.

Overrides:

elaborateForItem in class PullElaborator

Returns:

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

elaborateForUpdate

public UpdateEvaluator elaborateForUpdate()

Overrides:

elaborateForUpdate in class Elaborator