com.ugos.jiprolog.engine

Class JIPXCall

java.lang.Object

com.ugos.jiprolog.engine.JIPXCall

Direct Known Subclasses:

AbsoluteFileName2, AccessFile2, Append2, CharAtom2, CopyOfStreamProperty3, CopyTerm2, CurrentInput1, CurrentOutput1, CurrentStream1, DeleteFile1, Dir1, EOF1, FileAttributes7, Findall3, FlushOutput1, FreeVariables2, Gensym2, Get02, JIPCatch3, JIPCreateObject3, JIPGet3, JIPGetClass2, JIPGetConstructors2, JIPGetFields2, JIPGetMethods2, JIPInvoke4, JIPReleaseObject1, JIPSet3, JIPThrow1, MakeDirectory1, Name2, Nl1, Numbervars3, PeekByte2, Read2, RenameFile2, See2, Seen1, SetInput1, SetOutput1, Shell2, Sleep1, Statistics0, StreamHandle1, StreamPosition3, StreamProperty3, Tell2, Time8, Told1, Vars2, Write2, WriteCanonical2, Writeq2, XMLRead1

public abstract class JIPXCall
extends Object

JIPXCall is the base class for custom built-in predicates.
See the section "How to write a custom built-in predicate" in the Reference Manual

Version:

2.0

Author:

Ugo Chirico 2002
Home Page: http://www.ugochirico.com

Constructor Summary

Constructors

Constructor and Description
JIPXCall()

Method Summary

Methods

Modifier and Type	Method and Description
JIPEngine	getJIPEngine() Returns the current running JIPEngine object
JIPFunctor	getPredicate() Returns the functor of the predicate invoking this instance of JIPXCall class
int	getQueryHandle() Returns the handle of the current running query
abstract boolean	hasMoreChoicePoints() Invoked by xcall/2 to check if the custom predicate has more choice points on backtracking.
protected void	init() Called by xcall/2 to initialize this JIPXCall object
abstract boolean	unify(JIPCons params, Hashtable<JIPVariable,JIPVariable> varsTbl) Invoked by xcall/2 to check if the custom predicate unify with the passed parameters For more information see the section "How to write a custom built-in predicate" in the Reference Manual.

Methods inherited from class java.lang.Object

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

Constructor Detail

JIPXCall

public JIPXCall()

Method Detail

init

protected void init()

Called by xcall/2 to initialize this JIPXCall object

getJIPEngine

public final JIPEngine getJIPEngine()

Returns the current running JIPEngine object

Returns:

current running JIPEngine object

See Also:

JIPEngine

getQueryHandle

public final int getQueryHandle()

Returns the handle of the current running query

Returns:

handle of the current running query

getPredicate

public final JIPFunctor getPredicate()

Returns the functor of the predicate invoking this instance of JIPXCall class

Returns:

functor of the predicate invoking this instance of JIPXCall class

See Also:

JIPFunctor

unify

public abstract boolean unify(JIPCons params,
            Hashtable<JIPVariable,JIPVariable> varsTbl)

Invoked by xcall/2 to check if the custom predicate unify with the passed parameters For more information see the section "How to write a custom built-in predicate" in the Reference Manual.

Parameters:

params - the parameters passed to the predicate.

Returns:

true if the custom predicates unify with the parameter passed, false otherwise

See Also:

JIPCons

hasMoreChoicePoints

public abstract boolean hasMoreChoicePoints()

Invoked by xcall/2 to check if the custom predicate has more choice points on backtracking.

Returns:

true if the custom predicate has more choice points, false otherwise.