org.apache.marmotta.ldpath.model.functions

Class FirstFunction<Node>

java.lang.Object

org.apache.marmotta.ldpath.api.functions.SelectorFunction<Node>

org.apache.marmotta.ldpath.model.functions.FirstFunction<Node>

Type Parameters:

Node - the node type used by the backend

All Implemented Interfaces:

NodeFunction<Collection<Node>,Node>, LDPathConstruct<Node>

public class FirstFunction<Node>
extends SelectorFunction<Node>

Selects the first node in the argument list.

Author:

Jakob Frank

Constructor Summary

Constructors

Constructor and Description
FirstFunction()

Method Summary

Methods

Modifier and Type	Method and Description
Collection<Node>	apply(RDFBackend<Node> rdfBackend, Node context, Collection<Node>... args) Apply the function to the list of nodes passed as arguments and return the result as type T.
String	getDescription() A short human-readable description of what the node function does.
String	getLocalName() Return the name of the NodeFunction for registration in the function registry
String	getSignature() A string describing the signature of this node function, e.g.

Methods inherited from class org.apache.marmotta.ldpath.api.functions.SelectorFunction

getPathExpression

Methods inherited from class java.lang.Object

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

Constructor Detail

FirstFunction

public FirstFunction()

Method Detail

apply

@SafeVarargs
public final Collection<Node> apply(RDFBackend<Node> rdfBackend,
                                 Node context,
                                 Collection<Node>... args)
                             throws IllegalArgumentException

Apply the function to the list of nodes passed as arguments and return the result as type T. Throws IllegalArgumentException if the function cannot be applied to the nodes passed as argument or the number of arguments is not correct.

Parameters:

args - a nested list of KiWiNodes

context - the context of the execution. Same as using the NodeSelector '.' as parameter.

Returns:

Throws:

IllegalArgumentException

getLocalName

public String getLocalName()

Return the name of the NodeFunction for registration in the function registry

Specified by:

getLocalName in class SelectorFunction<Node>

Parameters:

backend -

Returns:

getSignature

public String getSignature()

A string describing the signature of this node function, e.g. "fn:content(uris : Nodes) : Nodes". The syntax for representing the signature can be chosen by the implementer. This method is for informational purposes only.

Returns:

getDescription

public String getDescription()

A short human-readable description of what the node function does.

Returns: