blob: 1004c7f09b8a4d8460a8e14492579290529086c2 [file] [log] [blame]
package com.googlecode.prolog_cafe.builtin;
import com.googlecode.prolog_cafe.lang.*;
/**
<code>'$get_prolog_impl_flag'/2</code><br>
@author Mutsunori Banbara (banbara@kobe-u.ac.jp)
@author Naoyuki Tamura (tamura@kobe-u.ac.jp)
@version 1.0
*/
class PRED_$get_prolog_impl_flag_2 extends Predicate.P2 {
private static final SymbolTerm DEBUG = SymbolTerm.intern("debug");
private static final SymbolTerm MAX_ARITY = SymbolTerm.intern("max_arity");
public PRED_$get_prolog_impl_flag_2(Term a1, Term a2, Operation cont) {
arg1 = a1;
arg2 = a2;
this.cont = cont;
}
public Operation exec(Prolog engine) {
engine.setB0();
Term a1, a2;
a1 = arg1;
a2 = arg2;
a1 = a1.dereference();
a2 = a2.dereference();
if (a1.equals(DEBUG)) {
if (! a2.unify(SymbolTerm.intern(engine.getDebug()), engine.trail))
return engine.fail();
} else if (a1.equals(MAX_ARITY)) {
if (! a2.unify(new IntegerTerm(engine.getMaxArity()), engine.trail))
return engine.fail();
} else {
return engine.fail();
}
return cont;
}
}