| package jp.ac.kobe_u.cs.prolog.builtin; |
| import jp.ac.kobe_u.cs.prolog.lang.*; |
| /** |
| * <code>'$erase'/1</code><br> |
| * @author Mutsunori Banbara (banbara@kobe-u.ac.jp) |
| * @author Naoyuki Tamura (tamura@kobe-u.ac.jp) |
| * @version 1.1 |
| */ |
| class PRED_$erase_1 extends Predicate { |
| Term arg1; |
| |
| public PRED_$erase_1(Term a1, Predicate cont) { |
| arg1 = a1; |
| this.cont = cont; |
| } |
| |
| public PRED_$erase_1() {} |
| |
| public void setArgument(Term[] args, Predicate cont){ |
| arg1 = args[0]; |
| this.cont = cont; |
| } |
| |
| public int arity() { return 1; } |
| |
| public String toString() { return "$erase(" + arg1 + ")"; } |
| |
| public Predicate exec(Prolog engine) { |
| engine.setB0(); |
| Term a1 = arg1; |
| int idx; |
| |
| a1 = a1.dereference(); |
| if (! a1.isInteger()) |
| throw new IllegalTypeException(this, 1, "integer", a1); |
| idx = ((IntegerTerm)a1).intValue(); |
| engine.internalDB.erase(idx); |
| return cont; |
| } |
| } |