blob: 2023f67ee9ed4e00f69418aab51775379b525469 [file] [log] [blame]
package com.googlecode.prolog_cafe.builtin;
import com.googlecode.prolog_cafe.exceptions.IllegalTypeException;
import com.googlecode.prolog_cafe.exceptions.PInstantiationException;
import com.googlecode.prolog_cafe.exceptions.RepresentationException;
import com.googlecode.prolog_cafe.exceptions.SyntaxException;
import com.googlecode.prolog_cafe.lang.DoubleTerm;
import com.googlecode.prolog_cafe.lang.IntegerTerm;
import com.googlecode.prolog_cafe.lang.ListTerm;
import com.googlecode.prolog_cafe.lang.Operation;
import com.googlecode.prolog_cafe.lang.Predicate;
import com.googlecode.prolog_cafe.lang.Prolog;
import com.googlecode.prolog_cafe.lang.Term;
import com.googlecode.prolog_cafe.lang.VariableTerm;
/**
* <code>number_codes/2</code><br>
* @author Mutsunori Banbara (banbara@kobe-u.ac.jp)
* @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
* @version 1.1
*/
public class PRED_number_codes_2 extends Predicate.P2 {
public PRED_number_codes_2(Term a1, Term a2, Operation cont) {
arg1 = a1;
arg2 = a2;
this.cont = cont;
}
@Override
public Operation exec(Prolog engine) {
engine.setB0();
Term a1, a2;
a1 = arg1;
a2 = arg2;
a1 = a1.dereference();
a2 = a2.dereference();
if (Prolog.Nil.equals(a2))
throw new SyntaxException(this, 2, "character_code_list", a2, "");
if (a1 instanceof VariableTerm) { // number_codes(-Number, +CharCodeList)
StringBuffer sb = new StringBuffer();
Term x = a2;
while(! Prolog.Nil.equals(x)) {
if (x instanceof VariableTerm)
throw new PInstantiationException(this, 2);
if (! (x instanceof ListTerm))
throw new IllegalTypeException(this, 2, "list", a2);
Term car = ((ListTerm)x).car().dereference();
if (car instanceof VariableTerm)
throw new PInstantiationException(this, 2);
if (! (car instanceof IntegerTerm))
throw new RepresentationException(this, 2, "character_code");
// car is an integer
int i = ((IntegerTerm)car).intValue();
if (! Character.isDefined((char)i))
throw new RepresentationException(this, 2, "character_code");
sb.append((char)i);
x = ((ListTerm)x).cdr().dereference();
}
try {
if (! a1.unify(new IntegerTerm(Integer.parseInt(sb.toString())), engine.trail))
return engine.fail();
return cont;
} catch (NumberFormatException e) {}
try {
if(! a1.unify(new DoubleTerm(Double.parseDouble(sb.toString())), engine.trail))
return engine.fail();
return cont;
} catch (NumberFormatException e) {
throw new SyntaxException(this, 2, "character_code_list", a2, "");
}
} else if (((a1 instanceof IntegerTerm) || (a1 instanceof DoubleTerm))) { // number_codes(+Number, ?CharCodeList)
char[] chars = a1.toString().toCharArray();
Term y = Prolog.Nil;
for (int i=chars.length; i>0; i--) {
y = new ListTerm(new IntegerTerm(chars[i-1]), y);
}
if (! a2.unify(y, engine.trail) )
return engine.fail();
return cont;
} else {
throw new IllegalTypeException(this, 1, "number", a1);
}
}
}