com.icl.saxon.expr
Class EmptyNodeSet
public final class EmptyNodeSet
A node-set value no nodes
asBoolean , asNumber , asString , compare , conversionPreference , convertToJava , display , enumerate , enumerate , equals , evaluate , evaluateAsNodeSet , getCount , getDataType , getFirst , isSorted , notEquals , setSorted , sort |
asBoolean , asNumber , asString , compare , conversionPreference , convertToJava , equals , evaluate , getDependencies , inverse , notEquals , numericCompare , reduce , simplify , stringToNumber |
containsReferences , display , enumerate , evaluate , evaluateAsBoolean , evaluateAsNodeSet , evaluateAsNumber , evaluateAsString , getDataType , getDependencies , getStaticContext , indent , isContextDocumentNodeSet , make , outputStringValue , reduce , setStaticContext , simplify , usesCurrent |
asBoolean
public boolean asBoolean()
Evaluate as a boolean.
- asBoolean in interface NodeSetValue
- false
asString
public String asString()
Convert to string value
- asString in interface NodeSetValue
- an empty string
equals
public boolean equals(Value other)
Test whether this nodeset "equals" another Value
- equals in interface NodeSetValue
evaluate
public Value evaluate(Context context)
Evaluate the Node Set. This guarantees to return the result in sorted order.
- evaluate in interface NodeSetValue
context
- The context for evaluation (not used)
evaluateAsNodeSet
public NodeSetValue evaluateAsNodeSet(Context context)
Evaluate an expression as a NodeSet.
- evaluateAsNodeSet in interface NodeSetValue
context
- The context in which the expression is to be evaluated
- the value of the expression, evaluated in the current context
getCount
public int getCount()
Count the nodes in the node-set.
- getCount in interface NodeSetValue
- zero
getFirst
public NodeInfo getFirst()
Get the first node in the nodeset (in document order)
- getFirst in interface NodeSetValue
- null
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.
- isContextDocumentNodeSet in interface Expression
isSorted
public boolean isSorted()
Test whether the value is known to be sorted
- isSorted in interface NodeSetValue
- true if the value is known to be sorted in document order, false if it is not
known whether it is sorted.
notEquals
public boolean notEquals(Value other)
Test whether this nodeset "not-equals" another Value
- notEquals in interface NodeSetValue
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.
- setSorted in interface NodeSetValue
isSorted
- true if the caller wishes to assert that the nodes are in document order
and do not need to be further sorted
sort
public NodeSetValue sort()
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)
- sort in interface NodeSetValue
- the same NodeSetValue, after sorting. (Historic)