| package jp.ac.kobe_u.cs.prolog.builtin; |
| import jp.ac.kobe_u.cs.prolog.lang.*; |
| /** |
| <code>'$insert'/2</code><br> |
| @author Mutsunori Banbara (banbara@kobe-u.ac.jp) |
| @author Naoyuki Tamura (tamura@kobe-u.ac.jp) |
| @version 1.1 |
| */ |
| class PRED_$insert_2 extends Predicate { |
| public Term arg1, arg2; |
| |
| public PRED_$insert_2(Term a1, Term a2, Predicate cont) { |
| arg1 = a1; |
| arg2 = a2; |
| this.cont = cont; |
| } |
| |
| public PRED_$insert_2(){} |
| |
| public void setArgument(Term[] args, Predicate cont) { |
| arg1 = args[0]; |
| arg2 = args[1]; |
| this.cont = cont; |
| } |
| |
| public int arity() { return 2; } |
| |
| public String toString() { |
| return "$insert(" + arg1 + "," + arg2 + ")"; |
| } |
| |
| public Predicate exec(Prolog engine) { |
| engine.setB0(); |
| Term a1, a2; |
| a1 = arg1; |
| a2 = arg2; |
| int idx; |
| |
| a2 = a2.dereference(); |
| if (! a2.isVariable()) |
| throw new IllegalTypeException(this, 2, "variable", a2); |
| a1 = a1.dereference(); |
| idx = engine.internalDB.insert(a1); |
| if (! a2.unify(new IntegerTerm(idx), engine.trail)) |
| return engine.fail(); |
| return cont; |
| } |
| } |