serene-simple/src/main/java/serene/simple/builtin/MinusFn.java

53 lines
1.6 KiB
Java

/**
* Serene (simple) - A PoC lisp to collect data on Serenes concepts
* Copyright (C) 2019-2020 Sameer Rahmani <lxsameer@gnu.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
package serene.simple.builtin;
import java.util.List;
import serene.simple.IScope;
import serene.simple.SNumber;
import serene.simple.SereneException;
public class MinusFn extends AFn {
public String fnName() {
return "-";
};
public Object eval(IScope scope) throws SereneException{
List<Object> args = this.arguments();
if (args.size() == 0) {
throw new SereneException(
"ArityError: You need 1 or more parameters for this functions.");
}
SNumber.IOps result = SNumber.createNumber(args.get(0));
try {
for(Object x: args.subList(1, args.size())) {
result = (SNumber.IOps) result.subtract(x);
}
}
catch (IndexOutOfBoundsException e) {}
return result.value();
}
}