com.icl.saxon.expr

Class 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.
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

asBoolean, asNumber, asString, compare, conversionPreference, convertToJava, display, enumerate, enumerate, equals, evaluate, evaluateAsNodeSet, getCount, getDataType, getFirst, isSorted, notEquals, setSorted, sort

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

asBoolean, asNumber, asString, compare, conversionPreference, convertToJava, equals, evaluate, getDependencies, inverse, notEquals, numericCompare, reduce, simplify, stringToNumber

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

containsReferences, display, enumerate, evaluate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getDataType, getDependencies, getStaticContext, indent, isContextDocumentNodeSet, make, outputStringValue, reduce, setStaticContext, simplify, usesCurrent

Constructor Details

NodeSetIntent

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

Method Details

asBoolean

public boolean asBoolean()
            throws XPathException
Evaluate as a boolean.
Overrides:
asBoolean in interface NodeSetValue
Returns:
true if the node set is not empty

asString

public String asString()
            throws XPathException
Convert to string value
Overrides:
asString in interface NodeSetValue
Returns:
the value of the first node in the node-set if there is one, otherwise an empty string

enumerate

public NodeEnumeration enumerate()
            throws XPathException
Return an enumeration of this nodeset value.
Overrides:
enumerate in interface NodeSetValue

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.
Overrides:
getCount in interface NodeSetValue

getFirst

public NodeInfo getFirst()
            throws XPathException
Get the first node in the nodeset (in document order)
Overrides:
getFirst in interface NodeSetValue
Returns:
the first node

getNodeSetExpression

public NodeSetExpression getNodeSetExpression()
Get the encapsulated NodeSetExpression

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 interface Expression

isSorted

public boolean isSorted()
            throws XPathException
Test whether the value is known to be sorted
Overrides:
isSorted in interface NodeSetValue
Returns:
true if the value is known to be sorted in document order, false if it is not known whether it is sorted.

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.

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.
Overrides:
setSorted in interface 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

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)
Overrides:
sort in interface NodeSetValue
Returns:
the same NodeSetValue, after sorting.