An override for efun::environment with arguments to travel up the inventory of a given object to find all environments in order upwards

efun_environment_override.c

/* Returns the environment of an object, or all the environments above an
 * object, or a single environment at a given position.
 *
 * Example:
 * backpack
 * -> pouch
 *    -> bean
 *
 * environment( bean ) ; // returns pouch
 * environment( bean, 0 ) ; // returns pouch
 * environment( bean, 1 ) ; // returns backpack
 * environment( bean, -1 ) ; // returns ({ pouch, backpack })
 * environment( bean, 902839) ; // returns 0
 *
 * if called from within the bean object, argument 1 is unnecessary
 * environment() ; // returns pouch
 * environment( 0 ) ; // returns pouch
 * environment( 1 ) ; // returns backpack
 * environment( -1 ) ; // returns ({ pouch, backpack })
 * environment( 902839 ) ; // returns 0 
 */

varargs mixed environment( mixed arg1, int arg2 )
{
   int depth ;
   object ob ;

   if( nullp( arg1 ) )
   {
      ob = previous_object() ;
      depth = 1;
   }
   else if( objectp( arg1 ) )
   {
      ob = arg1 ;
      depth = 1 ;
   }
   else if( intp( arg1 ) )
   {
      ob = previous_object() ;
      depth = arg1 + 1 ;
   }

   if( !nullp( arg2 ) )
   {
      if( intp( arg2 ) )
      {
         if( intp( arg1 ) )
         {
            error("environment: Error in argument 2") ;
         }
         depth = arg2 + 1 ;
      }
   }

   if( depth == 0 ) // retrieve all
   {
      object env, *envs = ({ }) ;

      while( env = efun::environment( ob ) )
      {
         envs = ({ envs..., env }) ;
         ob = env ;
      }
      return envs ;
   }
   else
   {
      object env ;

      while( depth-- && env = efun::environment( ob ) )
      {
         ob = env ;
      }

      return env ;
   }   
}