Package net.sf.saxon.expr.elab

Class FallbackElaborator

  • Direct Known Subclasses:
    ComplexNodePushElaborator
    public class FallbackElaborator
extends Elaborator
    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.

    • Constructor Detail

      • FallbackElaborator

        public FallbackElaborator()

    • Method Detail

      • eagerly

        public SequenceEvaluator eagerly()
        Description copied from class: Elaborator
        Get a function that evaluates the underlying expression eagerly
        Overrides:
        eagerly in class Elaborator
        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.

      • lazily

        public SequenceEvaluator lazily​(boolean repeatable,
                                boolean lazyEvaluationRequired)
        Description copied from class: Elaborator
        Get a function that evaluates the underlying expression lazily
        Overrides:
        lazily in class Elaborator
        Parameters:
        repeatable - true if the resulting Sequence must be usable repeatedly; false if it only needs to be used once
        lazyEvaluationRequired - 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)

      • 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
        Specified by:
        elaborateForPush in class Elaborator
        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.
        Specified by:
        elaborateForItem in class Elaborator
        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.
        Specified by:
        elaborateForBoolean in class Elaborator
        Returns:
        an evaluator for the expression that returns a boolean.

      • elaborateForUnicodeString

        public UnicodeStringEvaluator elaborateForUnicodeString​(boolean zeroLengthWhenAbsent)
        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 class Elaborator
        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.