jTrolog.engine

Class BindingsTable

java.lang.Object

jTrolog.engine.BindingsTable

public class BindingsTable
extends Object

Keeps track of what variables are bound to what Terms and at which ChoicePoint this connection was made. now, the BindingsTable never receives anything that is not Wrapped. All Structs sent in are wrapped as a mfck. the unifyBranch is now possible to run without generating new objects when the getArg is called. all the methods that add vars and get vars from the bidnings table is now given both Var and context (and link term and its context) a problem is that the stackMap needs to be subsumed into the bindings table since it needs to retract the links done by a current owner. I don't think I can remove the current owner as a separate map since it provides a rollback function. What I can do is stringToStructList WrapVars for it only and then move these into and out of the bindingsMap

Author:

janerist@stud.ntnu.no, ivar.orstavik@hist.no

Constructor Summary

Constructors

Constructor and Description
BindingsTable()

Method Summary

Modifier and Type	Method and Description
Struct	createStructList(Collection complete)
Number	evalExpression(Prolog prolog, EvaluableTerm expression)
void	expandLinkTable(int newSize)
Term	flatCopy(Term original, int keepCtx)
int	getUniqueExecutionCtxID()
Term	resolve(Term term)
Term	resolveFaster(Term term, int ctx)
Iterator	structListIterator(Struct origin, boolean skipLastEmptyList)
boolean	unify(Term t0, Term t1)
static Term	unWrap(Term l)
Term	variant(Term original) See 7.1.6.1 Variants of a term in the ISO spec this method resolves all the terms children.
Term	wrapWithID(Term t)
static Term	wrapWithID(Term t, int renameVarID)

Methods inherited from class java.lang.Object

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

Constructor Detail

BindingsTable

public BindingsTable()

Method Detail

getUniqueExecutionCtxID

public int getUniqueExecutionCtxID()

expandLinkTable

public void expandLinkTable(int newSize)

unify

public boolean unify(Term t0,
                     Term t1)

wrapWithID

public Term wrapWithID(Term t)

wrapWithID

public static Term wrapWithID(Term t,
                              int renameVarID)

unWrap

public static Term unWrap(Term l)

evalExpression

public Number evalExpression(Prolog prolog,
                             EvaluableTerm expression)
                      throws PrologException,
                             Throwable

Parameters:

prolog -

expression -

Returns:

result of the evaluation as a Number

Throws:

PrologException - instantiation error if one of the Variables to be evaluated is not instantiated type_error(Evaluable, other) if a part in the evaluable Term is not evaluable

Throwable - any other exception that might be thrown by parts of the expression to be evaluated

resolve

public Term resolve(Term term)

resolveFaster

public Term resolveFaster(Term term,
                          int ctx)

structListIterator

public Iterator structListIterator(Struct origin,
                                   boolean skipLastEmptyList)
                            throws PrologException

Throws:

PrologException

createStructList

public Struct createStructList(Collection complete)

variant

public Term variant(Term original)

See 7.1.6.1 Variants of a term in the ISO spec this method resolves all the terms children. Not sure if this is in line with the spec.

Parameters:

original - such as - f(X,Y,X) - g(A,B) - P + Q

Returns:

a variant of the original such as - f(_1, _2, _1) - g(_1, _2) - _1 + _2

flatCopy

public Term flatCopy(Term original,
                     int keepCtx)