| com.hp.hpl.jena.reasoner.rulesys.Builtin
All known Subclasses: com.hp.hpl.jena.reasoner.rulesys.builtins.BaseBuiltin,
| Builtin | | public interface Builtin (Code) | | Rules employ builtins to do all tests and actions other than simple triple
matches and triple creation.
Builtins can be invoked in two contexts. In the head of forward rules they perform
some action based on the variable bindings generated by the body and additional context
(the graph being reasoned over, the set of triples bound by the body). In the body
of rules they perform tests, and additional variable bindings.
The mapping from the rule definition (which uses functors to hold the parsed call)
to the java implementation of the builtin is done via the
BuiltinRegistry BuiltinRegistry which can
be user extended.
author:
Dave Reynolds
version:
$Revision: 1.13 $ on $Date: 2008/01/02 12:07:47 $ |
| Method Summary | |
| public boolean | bodyCall(Node[] args, int length, RuleContext context)
This method is invoked when the builtin is called in a rule body. | | public int | getArgLength()
Return the expected number of arguments for this functor or 0 if the number is flexible. | | public String | getName()
Return a convenient name for this builtin, normally this will be the name of the
functor that will be used to invoke it and will often be the final component of the
URI. | | public String | getURI()
Return the full URI which identifies this built in. | | public void | headAction(Node[] args, int length, RuleContext context)
This method is invoked when the builtin is called in a rule head. | | public boolean | isMonotonic()
Returns false if this builtin is non-monotonic. | | public boolean | isSafe()
Returns false if this builtin has side effects when run in a body clause,
other than the binding of environment variables. |
| bodyCall | | public boolean bodyCall(Node[] args, int length, RuleContext context)(Code) | | This method is invoked when the builtin is called in a rule body.
Parameters:
args - the array of argument values for the builtin, this is an array of Nodes, some of which may be Node_RuleVariables.
Parameters:
length - the length of the argument list, may be less than the length of the args arrayfor some rule engines
Parameters:
context - an execution context giving access to other relevant data return true if the buildin predicate is deemed to have succeeded inthe current environment |
| getArgLength | | public int getArgLength()(Code) | | Return the expected number of arguments for this functor or 0 if the number is flexible.
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| getName | | public String getName()(Code) | | Return a convenient name for this builtin, normally this will be the name of the
functor that will be used to invoke it and will often be the final component of the
URI.
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| getURI | | public String getURI()(Code) | | Return the full URI which identifies this built in.
|
| headAction | | public void headAction(Node[] args, int length, RuleContext context)(Code) | | This method is invoked when the builtin is called in a rule head.
Such a use is only valid in a forward rule.
Parameters:
args - the array of argument values for the builtin, this is an array of Nodes.
Parameters:
length - the length of the argument list, may be less than the length of the args arrayfor some rule engines
Parameters:
context - an execution context giving access to other relevant data |
| isMonotonic | | public boolean isMonotonic()(Code) | | Returns false if this builtin is non-monotonic. This includes non-monotonic checks like noValue
and non-monotonic actions like remove/drop. A non-monotonic call in a head is assumed to
be an action and makes the overall rule and ruleset non-monotonic.
Most JenaRules are monotonic deductive closure rules in which this should be false.
|
| isSafe | | public boolean isSafe()(Code) | | Returns false if this builtin has side effects when run in a body clause,
other than the binding of environment variables.
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