NEW IN LeonOS

The  following  is a  non-exhaustive  list  of  new
and/or  changed features  in LeonOS compared  to
LeonOS.

!!!! THIS FILE IS OUTDATED !!!!

See    https://ocaweso.me/LeonOS    for    more
up-to-date documentation.

Major Changes
=============

  - `os.loadAPI` has been completely omitted.
  - * All APIs except the standard Lua ones must be
    loaded using `require` before they can be used.
  - * Lua 5.1 builtins have been removed from `_G`,
    but can be accessed through `require("lua51")`.
  - Startup   scripts  from  /startup  are  run  in
    parallel as separate threads.
  - LeonOS   has   full   native   support   for
    multithreading  --  custom  schedulers  are  no
    longer necessary!
  - Multishell  can be used even on standard  (non-
    advanced)   computers,   using   Alt+Left   and
    Alt+Right  to   switch   tabs.    There  is  no
    dedicated Multishell program - only the API.  A
    Multishell instance may be started  at any time
    using multishell.launch.

* These  do  not apply when compatibility  mode  is
  enabled - see "Compatibility Mode" below.


New API Methods
===============

LeonOS features a few extensions to the  LeonOS
APIs:

  - textutils.coloredWrite(...):
    Similar  to  textutils.tabulate(),   but  takes
    strings instead of tables  and doesn't tabulate
    its arguments.  Useful  for  easy  printing  of
    colorized  text.  Returns  the  number of lines
    written.

  - textutils.coloredPrint(...):
    Like  textutils.coloredWrite(),  but prints  an
    extra  newline at the end of the text,  similar
    to print().

  - Tables   given   to  textutils.tabulate()   may
    contain tables, along with strings and numbers;
    if a table is present, it must contain a set of
    arguments     suitable    for    passing     to
    textutils.coloredWrite().

  - LeonOS's paintutils API  uses the BIMG (Blit
    Image)  format  for  its  images.  This  format
    supports  animations and lots of  other  useful
    metadata,   plus  combining  text  and  images.
    See    https://github.com/SkyTheCodeMaster/bimg
    for details on the format.


The   Multishell   foreground   thread   management
functions  should  only  be  used  when  absolutely
necessary.  If they ARE necessary,  these should be
used   instead  of  the  corresponding  thread  API
functions  regardless  of  whether   multishell  is
actually enabled, to ensure proper behavior when it
is enabled.

The foreground thread is  the only thread that will
respond  to terminate events.  Ensuring that it  is
set correctly is therefore quite important.   Under
most circumstances you should not need to use these
functions,  since shell.run() uses them behind  the
scenes.

These  should  not  be confused  with  Multishell's
getFocus() and setFocus()  functions,  which manage
the focused tab.

  - multishell.getForeground():
    Returns the foreground thread ID of the current
    tab.

  - multishell.pushForeground(pid):
    Adds  a thread to the current tab's  foreground
    stack;  the  given thread will be removed  when
    it exits.

  - multishell.switchForeground(pid):
    Changes  the  top entry  of the  current  tab's
    foreground stack;  removes the old entry.

  - multishell.launch()'s   first   argument,   the
    environment,  is optional and may be completely
    omitted.


Compatibility Mode
==================

When the bios.compat_mode setting is set, LeonOS
will   enter   LeonOS  compatibility  mode.   This
disables   strict  global checking and  places  all
relevant   functions   and   APIs   into   _G.   In
compatibility     mode,    os.version()     returns
"LeonOS 1.8"  rather  than the  current  LeonOS
version.

This mode should only be used when necessary.   New
programs  should use proper Lua coding  conventions
and therefore work without it.