Helfer AbstractFlag

Jan Burse, erstellt 17. Aug 2019
package jekpro.model.builtin;
import jekpro.model.inter.Engine;
import jekpro.model.molec.Display;
import jekpro.model.molec.EngineException;
import jekpro.model.molec.EngineMessage;
import jekpro.reference.structure.SpecialUniv;
import jekpro.tools.term.SkelAtom;
/**
* <p>Abstract base class for flags.</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 abstract class AbstractFlag<T> {
public final static String OP_ON = "on";
public final static String OP_OFF = "off";
public final static String OP_FALSE = "false";
public final static String OP_NULL = "null";
protected final int id;
/**
* <p>Create a flag.</p>
*
* @param i The id of the flag.
*/
protected AbstractFlag(int i) {
id = i;
}
/************************************************************/
/* Thread Flags */
/************************************************************/
/**
* <p>Retrieve the value of this flag.</p>
*
* @param t The object.
* @param en The engine.
* @return The value.
* @throws EngineException Shit happens.
* @throws EngineMessage Shit happens.
*/
public abstract Object getObjFlag(T t, Engine en)
throws EngineException, EngineMessage;
/**
* <p>Set the value of a this flag.</p>
*
* @param t The object.
* @param m The value skel.
* @param d The value display.
* @param en The engine.
* @return True if flag could be changed, otherwise false.
* @throws EngineMessage Shit happens.
*/
public abstract boolean setObjFlag(T t, Object m, Display d, Engine en)
throws EngineMessage;
/************************************************************/
/* On & Off Atom */
/************************************************************/
/**
* <p>Convert an atom to a switch. Will throw exception
* when the atom is not well formed.</p>
*
* @param m The switch skel.
* @param d The switch display.
* @return The switch value.
* @throws EngineMessage Shit happens.
*/
public static boolean atomToSwitch(Object m, Display d)
throws EngineMessage {
String fun = SpecialUniv.derefAndCastString(m, d);
if (fun.equals(OP_ON)) {
return true;
} else if (fun.equals(OP_OFF)) {
return false;
} else {
throw new EngineMessage(EngineMessage.domainError(
EngineMessage.OP_DOMAIN_FLAG_VALUE, m), d);
}
}
/**
* <p>Convert a switch to an atom.</p>
* <p>A switch has the following syntax:</p>
* <pre>
* switch = "on" | "off".
* </pre>
*
* @param s The switch value.
* @return The switch skel.
*/
public static SkelAtom switchToAtom(boolean s) {
return new SkelAtom(s ? OP_ON : OP_OFF);
}
}

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