Module dev.metaschema.core

Package dev.metaschema.core.metapath.function.library

Class FnZeroOrOne

java.lang.Object

dev.metaschema.core.metapath.function.library.FnZeroOrOne

public final class FnZeroOrOne
extends Object

Implements the XPath 3.1 fn:zero-or-one function.

Method Summary

Modifier and Type	Method	Description
static ISequence<?>	fnZeroOrOne(ISequence<?> sequence)	Check that the provided sequence has zero or one items.

Methods inherited from class java.lang.Object

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

Method Details

fnZeroOrOne

@NonNull
public static ISequence<?> fnZeroOrOne(@NonNull
 ISequence<?> sequence)

Check that the provided sequence has zero or one items.

Based on the XPath 3.1 fn:zero-or-one function.

Parameters:

sequence - the sequence to evaluate

Returns:

the sequence if it has zero or one items

Throws:

InvalidArgumentFunctionException - with the code InvalidArgumentFunctionException.INVALID_ARGUMENT_ZERO_OR_ONE if the sequence contains more than one item