/*
* Jatha - a Common LISP-compatible LISP library in Java.
* Copyright (C) 1997-2005 Micheal Scott Hewett
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* For further information, please contact Micheal Hewett at
* hewett@cs.stanford.edu
*
*/
/**
* $Id: MacroexpandPrimitive.java,v 1.3 2007/03/22 02:12:50 mhewett Exp $
*/
package org.jatha.compile;
import org.jatha.Jatha;
import org.jatha.dynatype.LispPackage;
import org.jatha.dynatype.LispValue;
import org.jatha.machine.SECDMachine;
/**
* <p>Returns the expansion of the form named. Otherwise the form will be returned as is.</p>
* <p>(macroexpand form)</p>
*
* @author <a href="mailto:Ola.Bini@itc.ki.se">Ola Bini</a>
* @version $Revision: 1.3 $
*/
public class MacroexpandPrimitive extends LispPrimitive {
public MacroexpandPrimitive(final Jatha lisp) {
super(lisp, "MACROEXPAND", 1);
}
public void Execute(final SECDMachine machine) {
final LispValue form = machine.S.pop();
LispValue now = expand(form);
LispValue lastOne = form;
while(now != lastOne && now.basic_consp() && !(now == f_lisp.NIL)) {
lastOne = now;
now = expand(now);
}
machine.S.push(now);
machine.C.pop();
}
private LispValue expand(final LispValue form) {
final LispValue carForm = form.car();
if(carForm.fboundp() == f_lisp.T && carForm.symbol_function() != null && carForm.symbol_function().basic_macrop()) {
return f_lisp.eval(f_lisp.makeCons(f_lisp.EVAL.intern("%%%" + carForm.symbol_name().toStringSimple(),(LispPackage)f_lisp.findPackage("SYSTEM")),quoteList(form.cdr())));
} else {
return form;
}
}
private LispValue quoteList(final LispValue intern) {
LispValue ret = f_lisp.NIL;
for(final java.util.Iterator iter = intern.iterator();iter.hasNext();) {
final LispValue curr = (LispValue)iter.next();
ret = f_lisp.makeCons(f_lisp.makeList(f_lisp.QUOTE,curr),ret);
}
return ret.nreverse();
}
}// MacroexpandPrimitive