ListEntry (Apache Jena)

java.lang.Object
- org.apache.jena.reasoner.rulesys.builtins.BaseBuiltin
- - org.apache.jena.reasoner.rulesys.builtins.ListEntry

All Implemented Interfaces:

Builtin
```
public class ListEntry
extends BaseBuiltin
```
listEntry(?list, ?index, ?val) will bind ?val to the ?index'th entry in the RDF list ?list. If there is no such entry the variable will be unbound and the call will fail. Only useable in rule bodies.

Field Summary
- Fields inherited from class org.apache.jena.reasoner.rulesys.builtins.BaseBuiltin
  BASE_URI

Constructor Summary

Constructors
Constructor Description

ListEntry()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`bodyCall(Node[] args, int length, RuleContext context)`	This method is invoked when the builtin is called in a rule body.
`int`	`getArgLength()`	Return the expected number of arguments for this functor or 0 if the number is flexible.
`java.lang.String`	`getName()`	Return a name for this builtin, normally this will be the name of the functor that will be used to invoke it.

Methods inherited from class org.apache.jena.reasoner.rulesys.builtins.BaseBuiltin
checkArgs, getArg, getURI, headAction, isMonotonic, isSafe

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ListEntry
```
public ListEntry()
```
- Method Detail
  - getName
```
public java.lang.String getName()
```
    Return a name for this builtin, normally this will be the name of the functor that will be used to invoke it.
  - getArgLength
```
public int getArgLength()
```
    Return the expected number of arguments for this functor or 0 if the number is flexible.
    
    Specified by:
    
    getArgLength in interface Builtin
    
    Overrides:
    
    getArgLength in class BaseBuiltin
  - bodyCall
```
public boolean bodyCall(Node[] args,
                        int length,
                        RuleContext context)
```
    This method is invoked when the builtin is called in a rule body.
    
    Specified by:
    
    bodyCall in interface Builtin
    
    Overrides:
    
    bodyCall in class BaseBuiltin
    
    Parameters:
    
    args - the array of argument values for the builtin, this is an array of Nodes, some of which may be Node_RuleVariables.
    
    length - the length of the argument list, may be less than the length of the args array for some rule engines
    
    context - an execution context giving access to other relevant data
    
    Returns:
    
    return true if the buildin predicate is deemed to have succeeded in the current environment