com.hp.hpl.jena.sparql.function.library
Class eval

java.lang.Object
  com.hp.hpl.jena.sparql.function.library.eval

All Implemented Interfaces:

Function

public class eval
extends java.lang.Object
implements Function

Function that evaluates an expression - catches evaluation failures and returns false. Mainly used in extensions. Would be better if that were eval and this were "safe" or somesuch

Constructor Summary

eval()

Method Summary

void	build(java.lang.String uri, ExprList args) Called during query plan construction immediately after the construction of the extension instance.
NodeValue	exec(Binding binding, ExprList args, java.lang.String uri, FunctionEnv env) Processes unevaluated arguments

Methods inherited from class java.lang.Object

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

Constructor Detail

eval

public eval()

Method Detail

build

public void build(java.lang.String uri,
                  ExprList args)

Description copied from interface: Function

Called during query plan construction immediately after the construction of the extension instance. Can throw ExprBuildException if something is wrong (like wrong number of arguments).

Specified by:

build in interface Function

args - The parsed arguements

exec

public NodeValue exec(Binding binding,
                      ExprList args,
                      java.lang.String uri,
                      FunctionEnv env)

Processes unevaluated arguments

Specified by:

exec in interface Function

Parameters:

binding - The current solution

args - A list of unevaluated expressions

uri - The name of this

env - The execution context

Returns:

NodeValue - a value