Helfer SpecialArith

Jan Burse, erstellt 17. Aug 2019
package jekpro.frequent.advanced;
import jekpro.model.inter.AbstractSpecial;
import jekpro.model.inter.Engine;
import jekpro.model.molec.AbstractUndo;
import jekpro.model.molec.Display;
import jekpro.model.molec.EngineException;
import jekpro.model.molec.EngineMessage;
import jekpro.reference.arithmetic.EvaluableElem;
import jekpro.reference.arithmetic.SpecialCompare;
import jekpro.reference.arithmetic.SpecialEval;
import jekpro.tools.term.SkelCompound;
/**
* <p>Provides built-in predicates for the module arith.</p>
* <p/>
* Warranty & Liability
* To the extent permitted by applicable law and unless explicitly
* otherwise agreed upon, XLOG Technologies GmbH makes no warranties
* regarding the provided information. XLOG Technologies GmbH assumes
* no liability that any problems might be solved with the information
* provided by XLOG Technologies GmbH.
* <p/>
* Rights & License
* All industrial property rights regarding the information - copyright
* and patent rights in particular - are the sole property of XLOG
* Technologies GmbH. If the company was not the originator of some
* excerpts, XLOG Technologies GmbH has at least obtained the right to
* reproduce, change and translate the information.
* <p/>
* Reproduction is restricted to the whole unaltered document. Reproduction
* of the information is only allowed for non-commercial uses. Selling,
* giving away or letting of the execution of the library is prohibited.
* The library can be distributed as part of your applications and libraries
* for execution provided this comment remains unchanged.
* <p/>
* Restrictions
* Only to be distributed with programs that add significant and primary
* functionality to the library. Not to be distributed with additional
* software intended to replace any components of the library.
* <p/>
* Trademarks
* Jekejeke is a registered trademark of XLOG Technologies GmbH.
*/
public final class SpecialArith extends AbstractSpecial {
final static int SPECIAL_BETWEEN = 0;
final static int SPECIAL_ABOVE = 1;
/**
* <p>Create an arith special.</p>
*
* @param i The id.
*/
public SpecialArith(int i) {
super(i);
}
/**
* <p>Logically evaluate a term in a list of goals for the first time.</p>
* <p>The term is passed via the skel and display of the engine.</p>
* <p>The continuation is passed via the r and u of the engine.</p>
* <p>The new continuation is returned via the skel and display of the engine.</p>
*
* @param en The engine.
* @return True if the predicate succeeded, otherwise false.
* @throws EngineMessage Shit happens.
* @throws EngineException Shit happens.
*/
public final boolean moniFirst(Engine en)
throws EngineMessage, EngineException {
switch (id) {
case SPECIAL_BETWEEN:
Object[] temp = ((SkelCompound) en.skel).args;
Display ref = en.display;
Number num1 = SpecialEval.derefAndCastNumber(temp[0], ref);
Number num2 = SpecialEval.derefAndCastNumber(temp[1], ref);
AbstractUndo mark = en.bind;
int res = SpecialCompare.computeCmp(num1, num2);
while (res <= 0) {
if (en.unifyTerm(temp[2], ref, num1, Display.DISPLAY_CONST)) {
if (res != 0) {
/* create choice point */
en.choices = new ChoiceArith(en.choices, num1,
en.contskel, en.contdisplay, mark, id);
en.number++;
}
return true;
}
/* undo bindings */
en.fault = null;
en.releaseBind(mark);
if (en.fault != null)
throw en.fault;
num1 = EvaluableElem.add(num1, Integer.valueOf(1));
res = SpecialCompare.computeCmp(num1, num2);
}
return false;
case SPECIAL_ABOVE:
temp = ((SkelCompound) en.skel).args;
ref = en.display;
num1 = SpecialEval.derefAndCastNumber(temp[0], ref);
mark = en.bind;
while (true) {
if (en.unifyTerm(temp[1], ref, num1, Display.DISPLAY_CONST)) {
/* create choice point */
en.choices = new ChoiceArith(en.choices, num1,
en.contskel, en.contdisplay, mark, id);
en.number++;
return true;
}
/* undo bindings */
en.fault = null;
en.releaseBind(mark);
if (en.fault != null)
throw en.fault;
num1 = EvaluableElem.add(num1, Integer.valueOf(1));
}
default:
throw new IllegalArgumentException(AbstractSpecial.OP_ILLEGAL_SPECIAL);
}
}
}

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