com.icl.saxon.expr
Class NodeSetIntent

java.lang.Object
  com.icl.saxon.expr.Expression
      com.icl.saxon.expr.Value
          com.icl.saxon.expr.NodeSetValue
              com.icl.saxon.expr.NodeSetIntent

public class NodeSetIntent

extends NodeSetValue

A node-set value implemented intensionally. It is a wrapper round an Expression which can be evaluated independently of context, that is it has been reduced so there are no remaining context-dependencies.

Field Summary

Fields inherited from class com.icl.saxon.expr.Value

ANY, BOOLEAN, NODESET, NUMBER, OBJECT, STRING

Fields inherited from class com.icl.saxon.expr.Expression

staticContext

Constructor Summary

NodeSetIntent(NodeSetExpression exp, Controller controller)
Construct a node-set containing all the nodes in a NodeEnumeration

Method Summary

boolean	asBoolean() Evaluate as a boolean.
java.lang.String	asString() Convert to string value
NodeEnumeration	enumerate() Return an enumeration of this nodeset value.
int	getCount() Count the nodes in the node-set.
NodeInfo	getFirst() Get the first node in the nodeset (in document order)
NodeSetExpression	getNodeSetExpression() Get the encapsulated NodeSetExpression
boolean	isContextDocumentNodeSet() Determine, in the case of an expression whose data type is Value.NODESET, whether all the nodes in the node-set are guaranteed to come from the same document as the context node.
boolean	isSorted() Test whether the value is known to be sorted
NodeInfo	selectFirst(Context context) Return the first node in the nodeset (in document order)
void	setSorted(boolean isSorted) Set a flag to indicate whether the nodes are sorted.
NodeSetValue	sort() Sort the nodes into document order.

Methods inherited from class com.icl.saxon.expr.NodeSetValue

asNumber, compare, conversionPreference, convertToJava, display, enumerate, equals, evaluate, evaluateAsNodeSet, getDataType, notEquals

Methods inherited from class com.icl.saxon.expr.Value

getDependencies, inverse, numericCompare, reduce, simplify, stringToNumber

Methods inherited from class com.icl.saxon.expr.Expression

containsReferences, evaluateAsBoolean, evaluateAsNumber, evaluateAsString, getStaticContext, indent, make, outputStringValue, setStaticContext, usesCurrent

Methods inherited from class java.lang.Object

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

Constructor Detail

NodeSetIntent

public NodeSetIntent(NodeSetExpression exp,
                     Controller controller)
              throws XPathException

Construct a node-set containing all the nodes in a NodeEnumeration

Method Detail

getNodeSetExpression

public NodeSetExpression getNodeSetExpression()

Get the encapsulated NodeSetExpression

setSorted

public void setSorted(boolean isSorted)

Set a flag to indicate whether the nodes are sorted. Used when the creator of the node-set knows that they are already in document order.

Specified by:

setSorted in class NodeSetValue

Parameters:

isSorted - true if the caller wishes to assert that the nodes will be delivered in document order and do not need to be further sorted

isSorted

public boolean isSorted()
                 throws XPathException

Test whether the value is known to be sorted

Specified by:

isSorted in class NodeSetValue

Returns:

true if the value is known to be sorted in document order, false if it is not known whether it is sorted.

Throws:

XPathException

isContextDocumentNodeSet

public boolean isContextDocumentNodeSet()

Determine, in the case of an expression whose data type is Value.NODESET, whether all the nodes in the node-set are guaranteed to come from the same document as the context node. Used for optimization.

Overrides:

isContextDocumentNodeSet in class Expression

asString

public java.lang.String asString()
                          throws XPathException

Convert to string value

Specified by:

asString in class NodeSetValue

Returns:

the value of the first node in the node-set if there is one, otherwise an empty string

Throws:

XPathException

asBoolean

public boolean asBoolean()
                  throws XPathException

Evaluate as a boolean.

Specified by:

asBoolean in class NodeSetValue

Returns:

true if the node set is not empty

Throws:

XPathException

getCount

public int getCount()
             throws XPathException

Count the nodes in the node-set. Note this will sort the node set if necessary, to make sure there are no duplicates.

Specified by:

getCount in class NodeSetValue

Throws:

XPathException

sort

public NodeSetValue sort()
                  throws XPathException

Sort the nodes into document order. This does nothing if the nodes are already known to be sorted; to force a sort, call setSorted(false)

Specified by:

sort in class NodeSetValue

Returns:

the same NodeSetValue, after sorting.

Throws:

XPathException

getFirst

public NodeInfo getFirst()
                  throws XPathException

Get the first node in the nodeset (in document order)

Specified by:

getFirst in class NodeSetValue

Returns:

the first node

Throws:

XPathException

selectFirst

public NodeInfo selectFirst(Context context)
                     throws XPathException

Return the first node in the nodeset (in document order)

Parameters:

context - The context for the evaluation: not used

Returns:

the NodeInfo of the first node in document order, or null if the node-set is empty.

Throws:

XPathException

enumerate

public NodeEnumeration enumerate()
                          throws XPathException

Return an enumeration of this nodeset value.

Specified by:

enumerate in class NodeSetValue

Throws:

XPathException