net.sf.saxon.functions
Class CollatingFunction
java.lang.Object
net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.FunctionCall
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.CollatingFunction
- All Implemented Interfaces:
- Expression, java.io.Serializable
- Direct Known Subclasses:
- Compare, Contains, DeepEqual, DistinctValues, IndexOf, Minimax
- public abstract class CollatingFunction
- extends SystemFunction
Abstract superclass for all functions that take an optional collation argument
- See Also:
- Serialized Form
Methods inherited from class net.sf.saxon.functions.SystemFunction |
addContextDocumentArgument, checkArguments, computeCardinality, display, getDetails, getItemType, getName, getRequiredType, main, makeSystemFunction, useContextItemAsDefault |
Methods inherited from class net.sf.saxon.expr.ComputedExpression |
computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSpecialProperties, iterate, markTailFunctionCalls, setLineNumber, typeError |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
CollatingFunction
public CollatingFunction()
preEvaluate
public Expression preEvaluate(StaticContext env)
- preEvaluate: this method suppresses compile-time evaluation by doing nothing
(because collation definitions are not available statically)
- Overrides:
preEvaluate
in class FunctionCall
getAtomicComparer
protected AtomicComparer getAtomicComparer(int arg,
XPathContext context)
throws XPathException
- Get a AtomicComparer that can be used to compare values
- Parameters:
arg
- the position of the argument (starting at 0) containing the collation name.
If this argument was not supplied, the default collation is usedcontext
- The dynamic evaluation context.
- Throws:
XPathException
getCollator
protected java.util.Comparator getCollator(int arg,
XPathContext context,
boolean useDefault)
throws XPathException
- Get a collator suitable for comparing strings. Returns the collator specified in the
given function argument if present, otherwise returns the default collator.
- Parameters:
arg
- The argument position (counting from zero) that holds the collation
URI if presentcontext
- The dynamic contextuseDefault
- true if, in the absence of a collation argument, the default
collation should be used; false if the codepoint collation should be used.
- Returns:
- a Comparator, which will either be a java.text.Collator, or a CodepointCollator
- Throws:
XPathException