@c -*-texinfo-*-
@c This is part of the GNU MDK Reference Manual.
@c Copyright (C) 2000, 2001, 2003
@c   Free Software Foundation, Inc.
@c See the file mdk.texi for copying conditions.

@node mixal-mode.el, mixvm.el, Getting started, Top
@comment  node-name,  next,  previous,  up
@chapter mixal-mode.el

Everyone writing code will know how important a good editor is. Most
systems already come with Emacs. @sc{mdk} adds support to Emacs for
both writing and debugging MIX programs, see (@pxref{Emacs support})
for installing instructions. This chapter discusses the support for the
writing code, see (@pxref{mixvm.el}) for the discussion of the MIX
virtual machine support.

When everything is installed correctly, Emacs will select the right
mode for editing files ending with @code{.mixal}. If however you would
want to load mixal-mode on another file, you can do so with @code{M-x
mixal-mode}.

@menu
* Basics::                      Editing code, font locking and indentation.
* Help system::                 Using the interactive help system.
* Compiling and running::       Invoking compiler and/or virtual machine.
@end menu

@node Basics, Help system, mixal-mode.el, mixal-mode.el
@comment node-name, next, previous, up
@section Basics

The mode for editing mixal source files is inherited from
fundamental-mode, meaning that all your favorite editing operations
will still work. If you want a short introduction to Emacs, type
@kbd{C-h t} inside Emacs to start the tutorial.

Mixal mode adds font locking. If you do not have font locking globally
enabled, you can turn it on for mixal-mode by placing the following
line in your @file{.emacs} file:

@lisp
(add-hook 'mixal-mode-hook 'turn-on-font-lock)
@end lisp

You can also customize the colors used to colour your mixal code by
changing the requisite faces. This is the list of faces used by
mixal-mode:

@itemize
@item @var{font-lock-comment-face}
Face to use for comments.
@item @var{mixal-font-lock-label-face}
Face to use for label names.
@item @var{mixal-font-lock-operation-code-face}
Face to use for operation code names.
@item @var{mixal-font-lock-assembly-pseudoinstruction-face}
Face to use for assembly pseudo-instruction names.
@end itemize

@node Help system, Compiling and running, Basics, mixal-mode.el
@comment node-name, next, previous, up
@section Help system

When coding your program, you will be thinking, looking up
documentation and editing files. Emacs already helps you with editing
files, but Emacs can do much more. In particular, looking up
documentation is one of its strong points. Besides the info system
(which you are probably already using), mixal-mode defines commands
for getting particular information about a MIX operation code.

With @kbd{M-x mixal-describe-operation-code} (or its keyboard shortcut
@kbd{C-h o}) you will get the documentation about a particular MIX
operation code. Keep in mind that these are not assembly (MIXAL)
pseudoinstructions. When the @code{point} is around a MIXAL
pseudoinstruction in your source file, Emacs will recognize it and
will suggest the right MIX operation code.

@node Compiling and running, , Help system, mixal-mode.el
@comment node-name, next, previous, up
@section Compiling and running

After you have written your MIXAL program, you'll probably want to
test it. This can be done with the MIX virtual machine. First you will
need to compile your code into MIX byte code. This can be done within
Emacs with the command @kbd{M-x compile} (@kbd{C-c c}). In case of
compilation errors, you can jump to the offending source code line
with @kbd{M-x next-error}.

Once the program compiles without errors, you can debug or run
it. To invoke the debugger, use @kbd{M-x mixal-debug} (@kbd{C-c d}).
Emacs will open a @code{GUD} buffer where you can
use the debugging commands described in @xref{mixvm}.

If you just want to execute the program, you can do so with @kbd{M-x
mixal-run} (@kbd{C-c r}). This will invoke mixvm,
execute the program and show its output in a separate buffer.