% -*- slang -*-

% This file gets loaded whenever slsh runs.  Its primary purpose is to define
% some functions that are useful in scripts, and to set up some local paths

private define dir_exists (dir)
{
   if (dir == NULL) return 0;
   variable s = stat_file (dir);
   if (s == NULL) return 0;
   return stat_is ("dir", s.st_mode);
}

private define check_dirs (dirs)
{
   if (dirs == NULL)
     return NULL;

   variable new_dirs = String_Type[0];
   foreach (strchop (dirs, path_get_delimiter(), 0))
     {
	variable dir = ();
	if (dir_exists (dir))
	  new_dirs = [new_dirs, dir];
     }
   if (length (new_dirs) == 0)
     return NULL;
   return strjoin (new_dirs, char (path_get_delimiter()));
}

%!%+
%\function{prepend_to_slang_load_path}
%\synopsis{Prepend a directory to the load-path}
%\usage{prepend_to_slang_load_path (String_Type dir)}
%\description
% This function adds a directory to the beginning of the interpreter's
% load-path.
%\seealso{append_to_slang_load_path, set_slang_load_path}
%!%-
public define prepend_to_slang_load_path (p)
{
   p = check_dirs (p);
   if (p != NULL)
     set_slang_load_path (sprintf ("%s%c%s", p, path_get_delimiter (), get_slang_load_path ()));
}

%!%+
%\function{append_to_slang_load_path}
%\synopsis{Append a directory to the load-path}
%\usage{append_to_slang_load_path (String_Type dir)}
%\description
% This function adds a directory to the end of the interpreter's
% load-path.
%\seealso{prepend_to_slang_load_path, set_slang_load_path}
%!%-
public define append_to_slang_load_path (p)
{
   p = check_dirs (p);
   if (p != NULL)
     set_slang_load_path (sprintf ("%s%c%s", get_slang_load_path (), path_get_delimiter (), p));
}

% This function gets called from slsh after loading this file
public define __slsh_startup_hook ()
{
   () = evalfile ("autoload.sl");
#ifdef __INTERACTIVE__
   () = evalfile ("slshrl.sl");
#endif
}
prepend_to_slang_load_path (getenv (SLSH_PATH_ENV));

% Add local additions here

