Package net.sf.saxon.expr.elab
Class FallbackElaborator
java.lang.Object
net.sf.saxon.expr.elab.Elaborator
net.sf.saxon.expr.elab.FallbackElaborator
- Direct Known Subclasses:
ComplexNodePushElaborator
The FallbackElaborator performs elaboration of expressions for which no more specific
elaborator is available. It produces evaluation functions that simply call the
direct evaluation interfaces. Note that when a FallbackElaborator is used, the
entire contained subtree will be interpreted in the traditional way, with no benefit
from elaboration.
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioneagerly()
Get a function that evaluates the underlying expression eagerlyGet a function that evaluates the underlying expression in the form of a boolean, this being the effective boolean value of the expression.Get a function that evaluates the underlying expression in the form of aItem
.Get a function that evaluates the underlying expression in the form of aSequenceIterator
Get a function that evaluates the underlying expression in push mode, by writing events to anOutputter
elaborateForUnicodeString
(boolean zeroLengthWhenAbsent) Get a function that evaluates the underlying expression in the form of a unicode string, this being the result of applying fn:string() to the result of the expression.lazily
(boolean repeatable, boolean lazyEvaluationRequired) Get a function that evaluates the underlying expression lazilyMethods inherited from class net.sf.saxon.expr.elab.Elaborator
elaborateForString, elaborateForUpdate, getConfiguration, getExpression, handleNullString, handleNullUnicodeString, handlePossiblyNullString, handlePossiblyNullUnicodeString, setExpression
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Constructor Details
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FallbackElaborator
public FallbackElaborator()
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Method Details
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eagerly
Description copied from class:Elaborator
Get a function that evaluates the underlying expression eagerly- Overrides:
eagerly
in classElaborator
- Returns:
- an evaluator for the expression that returns a
GroundedValue
. The classSequenceEvaluator
is declared to return aSequence
not aGroundedValue
; we can't specialize it because it's a limitation of C# delegates, but the result can safely be cast toGroundedValue
.
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lazily
Description copied from class:Elaborator
Get a function that evaluates the underlying expression lazily- Overrides:
lazily
in classElaborator
- Parameters:
repeatable
- true if the resultingSequence
must be usable repeatedly; false if it only needs to be used oncelazyEvaluationRequired
- true if the expression MUST be evaluated lazily, for example to prevent spurious errors or side-effects if it has been lifted out of a loop- Returns:
- an evaluator for the expression that returns a
Sequence
(which may be a lazy sequence)
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elaborateForPull
Description copied from class:Elaborator
Get a function that evaluates the underlying expression in the form of aSequenceIterator
- Specified by:
elaborateForPull
in classElaborator
- Returns:
- an evaluator for the expression that returns a
SequenceIterator
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elaborateForPush
Description copied from class:Elaborator
Get a function that evaluates the underlying expression in push mode, by writing events to anOutputter
- Specified by:
elaborateForPush
in classElaborator
- Returns:
- an evaluator for the expression in push mode
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elaborateForItem
Description copied from class:Elaborator
Get a function that evaluates the underlying expression in the form of aItem
. This must only be called for expressions whose result has cardinality zero or one.- Specified by:
elaborateForItem
in classElaborator
- Returns:
- an evaluator for the expression that returns an
Item
, or null to represent an empty sequence.
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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.- Specified by:
elaborateForBoolean
in classElaborator
- Returns:
- an evaluator for the expression that returns a boolean.
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elaborateForUnicodeString
Description copied from class:Elaborator
Get a function that evaluates the underlying expression in the form of a unicode string, this being the result of applying fn:string() to the result of the expression.- Specified by:
elaborateForUnicodeString
in classElaborator
- Parameters:
zeroLengthWhenAbsent
- if true, then when the result of the expression is an empty sequence, the result of the StringEvaluator should be a zero-length string. If false, the return value should be null. For an expression or function that never returns an empty sequence (for example, a call on string() or normalize-space()), the argument has no effect.- Returns:
- an evaluator for the expression that returns a string.
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