com.saxonica.deploy
Class CompiledMemoClosure

java.lang.Object
  net.sf.saxon.value.Value
      com.saxonica.deploy.CompiledClosure
          com.saxonica.deploy.CompiledMemoClosure

All Implemented Interfaces:

java.io.Serializable, SequenceIterable, ValueRepresentation

public class CompiledMemoClosure
extends CompiledClosure

A CompiledMemoClosure is a closure that remembers the input values once they have been read the first time. It is similar in operation to the MemoClosure class used by the interpreter.

See Also:

Serialized Form

Nested Class Summary

class

CompiledMemoClosure.ProgressiveIterator A ProgressiveIterator starts by reading any items already held in the reservoir; when the reservoir is exhausted, it reads further items from the inputIterator, copying them into the reservoir as they are read.

Field Summary

protected static int	EMPTY
protected int	state

Fields inherited from class com.saxonica.deploy.CompiledClosure

cardinality, inputIterator, primitiveType

Fields inherited from class net.sf.saxon.value.Value

EMPTY_CLASS_ARRAY, INDETERMINATE_ORDERING

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Constructor Summary

CompiledMemoClosure(CompiledClosure input)

CompiledMemoClosure(SequenceIterator inputIterator, int primitiveType, int cardinality)

Method Summary

int	getLength() Get the length of the sequence
Item	itemAt(int n) Get the n'th item in the sequence (starting from 0).
SequenceIterator	iterate() Evaluate the expression in a given context to return an iterator over a sequence

Methods inherited from class com.saxonica.deploy.CompiledClosure

getCardinality, getItemType, getSchemaComparable, reduce

Methods inherited from class net.sf.saxon.value.Value

asItem, asItem, asIterator, asValue, checkPermittedContents, convertToJava, effectiveBooleanValue, equals, fromItem, getCanonicalLexicalRepresentation, getIterator, getStringValue, getStringValueCS, iterate, makeQNameValue, process, stringToNumber, toString

Methods inherited from class java.lang.Object

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

Field Detail

state

protected int state

EMPTY

protected static final int EMPTY

See Also:

Constant Field Values

Constructor Detail

CompiledMemoClosure

public CompiledMemoClosure(SequenceIterator inputIterator,
                           int primitiveType,
                           int cardinality)

CompiledMemoClosure

public CompiledMemoClosure(CompiledClosure input)

Method Detail

iterate

public SequenceIterator iterate()
                         throws XPathException

Evaluate the expression in a given context to return an iterator over a sequence

Overrides:

iterate in class CompiledClosure

Returns:

an iterator over the sequence of items

Throws:

XPathException - if a dynamic error occurs. This is possible only in the case of values that are materialized lazily, that is, where the iterate() method leads to computation of an expression that delivers the values.

itemAt

public Item itemAt(int n)
            throws XPathException

Description copied from class: Value

Get the n'th item in the sequence (starting from 0). This is defined for all Values, but its real benefits come for a sequence Value stored extensionally (or for a MemoClosure, once all the values have been read)

Overrides:

itemAt in class Value

Parameters:

n - position of the required item, counting from zero.

Returns:

the n'th item in the sequence, where the first item in the sequence is numbered zero. If n is negative or >= the length of the sequence, returns null.

Throws:

XPathException

getLength

public int getLength()
              throws XPathException

Get the length of the sequence

Overrides:

getLength in class CompiledClosure

Returns:

the number of items in the sequence

Throws:

XPathException