/***************************************************************************
                          whileblock.cpp  -  description
                             -------------------
    begin                : Thu Mar 20 20:43:35 2003
    copyright            : (C) 2002 by Cavalli Andrea
    email                : cavalli@bioc.unizh.ch
**************************************************************************/
/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#include <zeta/whileblock.h>
extern int interrupt;
ZObj * WhileBlock::eval(){ //exec_line done
  exec_line = line;

  ZObj * res = expr->eval();
  if(!is_zbool(res)){
    ZObj::remove(res);
    throw ZError(line,"Invalid expression");
  }

  ZBool * b = (ZBool*)res;
  while(b->data){
    if(interrupt){
      char buff[256];
      sprintf(buff,"excution of while block stopped at line %i",line);
      throw string(buff);
    } 

    ZObj * t;
    if(block!=NULL)
      t = block->eval();
    else 
      t = new ZStatus(true);


    if(is_zret(t)){
      return t;
    }

    if(is_zcont(t)){
      throw ZError(line,"continue not allowed in while block");
    }

    if(is_zbreak(t)){
      ZObj::remove(b);
      ZObj::remove(t);
      return new ZStatus(true);
    }

    ZObj::remove(t);
    ZObj::remove(b);
      
      
    b = (ZBool*) expr->eval();
  }

  ZObj::remove(b);
  return new ZStatus(true);
}