//
// Primitive.java : プリミティブ操作 (起動時にロードされる基本関数群)
//
//              This is a part of miolisp sourcefile
//              Copyright (C) 1998,99  Nishiyama, Naoki / Mio software lab. 
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program 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 General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//


import java.util.* ;
import java.io.* ;

public final class Primitive implements LispFunction {
  // Cons
  public static Object Cons(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Object a,d ;
    a = i.getNextObjEval("cons",e) ;
    d = i.getFinalObjEval("cons",e) ;
    return new Cons(a,d) ;
  }

  // List
  public static Object List(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    return i.getRestEval("list",e) ;
  }

  // Append (Recursive)
  private static Object _append(Object a,Object d) throws EvalException {
    if (a == SAtom.nil) return d ;
    Cons c = Evalutil.mustbecons("append :",a) ;
    return new Cons(c.car,_append(c.cdr,d)) ;
  }

  public static Object Append(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Object a,d ;
    a = i.getNextObjEval("append",e) ;
    d = i.getFinalObjEval("append",e) ;
    return _append(a,d) ;
  }

  // Quote
  public static Object Quote(Environment e,Object o) throws EvalException{
    return Evalutil.getarg1("quote :",o) ;
  }

  // Backquote
  private static Object _backquote(Environment e,Object o) throws Exception {
    if (o instanceof Cons) {
      Object ca = ((Cons)o).car , cd = ((Cons)o).cdr ;
      if (cd instanceof Cons) {
        Object ca2 = ((Cons)cd).car ;
        if (ca2 instanceof Cons) {
          if (((Cons)ca2).car == SAtom.commaat) {
            Cons c = Evalutil.mustbecons("backquote-atmark :",((Cons)ca2).cdr) ;
            return new Cons(_backquote(e,ca),Eval.eval(c.car,e)) ;
          }
        }  
      }
      if (ca == SAtom.comma) {
        Cons c = Evalutil.mustbecons("backquote-comma :",cd) ;
        return Eval.eval(c.car,e) ;
      }
      return new Cons(_backquote(e,ca),_backquote(e,cd)) ;
    }
    return o ;
  }

  public static Object Backquote(Environment e,Object o) throws Exception{
    return _backquote(e,Evalutil.getarg1("backquote :",o)) ;
  }

  // Lambda
  public static Object Lambda(Environment e,Object o) throws Exception {
    Cons c = Evalutil.mustbecons("lambda :",o) ;
    return new Lambda(e,c.car,c.cdr) ;
  }

  // Macro
  public static Object Macro(Environment e,Object o) throws Exception {
    Cons c = Evalutil.mustbecons("macro :",o) ;
    return new Macro(e,c.car,c.cdr) ;
  }

  // Car
  public static Object Car(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("car :",o),e) ;
    if (o == SAtom.nil) return SAtom.nil ;
    return Evalutil.mustbecons("car :",o).car ;
  }

  // Cdr
  public static Object Cdr(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("cdr :",o),e) ;
    if (o == SAtom.nil) return SAtom.nil ;
    return Evalutil.mustbecons("cdr :",o).cdr ;
  }

  // Null?
  public static Object Null(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("null :",o),e) ;
    return (o == SAtom.nil ? SAtom.t : SAtom.nil ) ;
  }

  // Atom?
  public static Object Atom(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("atom :",o),e) ;
    return (o instanceof Atom ? SAtom.t : SAtom.nil ) ;
  }

  // Setq (Special Form)
  public static Object Setq(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    SAtom    a = i.getNextSAtom("setq") ;
    Object   d = i.getFinalObjEval("setq",e) ;
    e.bind(a,d) ;
    return d ;
  }

  // Define (Special Form)
  public static Object Define(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    SAtom    a = i.getNextSAtom("define") ;
    Object   d = i.getFinalObjEval("define",e) ;
    a.setGlobal(d) ;
    return a ;
  }

  // Envaslist  (現在の環境の snapshot をリストにして返す)
  public static Object Envaslist(Environment e,Object o) throws Exception {
    return new Cons(e.toalist(),
                    new Cons(SAtom.getGlobalDic(),SAtom.nil)) ;
  }

  // Env (現在の環境の Environment オブジェクトを返す)
  public static Object Env(Environment e,Object o) throws Exception {
    return e ;
  }

  // If
  public static Object If(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Object co = i.getNextObjEval("if",e) ;
    Object th = i.getNextObj("if") ;

    // 第１引数の評価結果をみる
    if (co != SAtom.nil)  {
      return Eval.eval(th,e) ;
    }
    return Evalutil.evprogn(i.getRest(),e) ;
  }

  // Eq
  public static Object Eq(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Object a,d ;
    a = i.getNextObjEval("eq",e) ;
    d = i.getFinalObjEval("eq",e) ;
    return (a == d ? SAtom.t : SAtom.nil) ;
  }

  // Load
  public static Object Load(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("car :",o),e) ;
    if (!(o instanceof String)) {
      throw new EvalException("load : filename must be String") ;
    }

    return Sloader.load(e,(String)o) ;
  }

  // Print
  public static Object Print(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    i.doeach("print",new ListIter.cb(e) { 
      // Anonymous class (super is ListIter.cb)
      public boolean repeat(Object r) throws Exception {
        System.out.print(Sexpr.toStr(Eval.eval(r,env))+" ") ;
        return true ;
      }
    }) ;
    System.out.println() ;
    return SAtom.t ;
  }

  // Cond
  public static Object Cond(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    return i.doeach("cond",new ListIter.cb(e) { 
      // Anonymous class (super is ListIter.cb)
      public boolean repeat(Object r) throws Exception {
        Cons c = Evalutil.mustbecons("cond :",r) ;
        Object co = Eval.eval(c.car,env) ; // 条件式
        if (co != SAtom.nil) { // 成立時
          if (c.cdr != SAtom.nil) { 
            result = Evalutil.evprogn(c.cdr,env) ;
          } else { // 成立時の実行文のないときは、条件式の値を戻す。
            result = co ;
          }
          return false ; // 評価を打ち切る
        }
        return true ;
      }
    }) ;
  }

  // Reverse
  public static Object Reverse(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("reverse :",o),e) ;
    if (o == SAtom.nil) return o ; // (reverse '())
    ListIter i = new ListIter(Evalutil.mustbecons("reverse :",o)) ;
    return i.doeach("reverse",new ListIter.cb(e) {
      // Anonymous class (super is ListIter.cb)
      public boolean repeat(Object r) throws Exception {
        result = new Cons(r,result) ;
        return true ; // continue repeat
      }
    }) ;
  }

  // Equal
  private static boolean _equal(Object x,Object y) {
    if (x == y) return true ;
    if (x instanceof Atom) {
      if (y instanceof Atom) {
        return ((Atom)x).eq((Atom)y) ;
      }
    } else if (x instanceof Cons) {
      if (y instanceof Cons) {
        if (_equal(((Cons)x).car,((Cons)y).car)) {
          return _equal(((Cons)x).cdr,((Cons)y).cdr) ;
        }
      }
    } else if (x instanceof String) {
      if (y instanceof String) {
        return ((String)x).equals((String)y) ;
      }
    }

    return false ;
  }

  public static Object Equal(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Object a,d ;
    a = i.getNextObjEval("equal",e) ;
    d = i.getFinalObjEval("equal",e) ;
    return (_equal(a,d) ? SAtom.t : SAtom.nil) ;
  }

  // Rplaca
  public static Object Rplaca(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Cons   c = i.getNextConsEval("rplaca",e) ;
    Object d = i.getFinalObjEval("rplaca",e) ;
    c.car = d ;
    return c ;    
  }

  // Rplacd
  public static Object Rplacd(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Cons   c = i.getNextConsEval("rplacd",e) ;
    Object d = i.getFinalObjEval("rplacd",e) ;
    c.cdr = d ;
    return c ;    
  }

  // Progn
  public static Object Progn(Environment e,Object o) throws Exception {
    return Evalutil.evprogn(o,e) ;
  }

  // Prog1
  public static Object Prog1(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Object res = i.getNextObjEval("prog1",e) ;
    Evalutil.evprogn(i.getRest(),e) ;
    return res ;
  }

  // Mapcar
  public static Object Mapcar(Environment e,Object o) throws Exception {
    ListIter i = new ListIter(o) ;
    Object f = i.getNextObjEval("mapcar",e) ;
    Object a = i.getFinalObjEval("mapcar",e) ;
    ListIter j = new ListIter(a) ;
    // apply,funcall の代わり^^;
    Cons template = new Cons(f,new Cons(
                    new Cons(SAtom.quote,new Cons()),SAtom.nil)) ;
    return j.doeach("mapcar",new ListIter.cb(e,template) {
      // Anonymous class (super is ListIter.cb)
      Cons last = null,place = null ;
      public boolean repeat(Object r) throws Exception {
        if (place == null) {
          place = (Cons)((Cons)((Cons)((Cons)arg).cdr).car).cdr ;
        }
        place.car = r ;
        Cons n = new Cons(Eval.eval(arg,env),SAtom.nil) ;
        if (last == null) { // 第 1 要素か？
          result = n ;
        } else {
          last.cdr = n ;
        }
        last = n ;
        return true ;
      }
    }) ;
  }

  // Quit (System Exit)
  public static Object Quit(Environment e,Object o) throws Exception {
    if (o != SAtom.nil) {
      o = Eval.eval(Evalutil.getarg1("car :",o),e) ;
      if (o instanceof Number) {
        System.exit(((Number)o).intValue()) ;
      }
    }    
    System.exit(0) ;
    // not come here
    return null ;
  }

  // FuncBody
  public static Object funcbody(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("funcdef :",o),e) ;
    if (!(o instanceof Macro)) {
      throw new EvalException("funcdef : argument must be Macro or Lambda") ;
    }    
    return ((Macro)o).body ;
  }

  // Eval
  public static Object Eval(Environment e,Object o) throws Exception {
    o = Eval.eval(Evalutil.getarg1("(Primitive)eval :",o),e) ;
    return Eval.eval(o,e) ;
  }

  // Spawn - Eval expression under another thread
  public static Object Spawn(Environment e,Object o) throws Exception {
    MLThread mlt = new MLThread(e,Evalutil.getarg1("spawn :",o)) ;
    Thread t = new Thread(mlt) ;
    t.start() ;
    return mlt ;
  }
}