How to define a function in Zile Lisp

How to define a function in Zile Lisp

[Thorsten Jolitz]

Hi List, 

I recently discovered that the nice small and fast Emacs clone GNU Zile
(“Zile Is Lossy Emacs”) can be customized in its own .zile file with a
small subset of Emacs Lisp called Zile Lisp.

,--------------------------------------------------------------------
| For customization, Zile uses its own limited configuration language
| known as Zile Lisp. Zile Lisp is a tiny subset of Emacs Lisp that
| consists of the Zile commands plus ‘setq’.
`--------------------------------------------------------------------

(from: http://www.emacswiki.org/emacs/Zile)

Now I wonder how I can write my own functions in Zile lisp without
'defun' and other special forms, and without something like 'progn'
e.g.? 

There is a pdf manual for zile (immediate download:
http://tinyurl.com/bpo8dyr) that lists all Zile commands, but I can't
find any examples of Zile Lisp beyond simple customization settings with
'setq'. 

So here is a question/challenge for the Emacs Lisp experts (maybe there
is even somebody on the list who used Zile Lisp before): 

How can I define a function (that is at least a sequence of Zile/Emacs
commands) only with 'setq' and the navigation/editing functions? and what
trick could simulate conditional execution when there are (apparently)
no conditionals in Zile Lisp?

Or is this question unreasonable, and the only reasonable way to add
functionality to Zile is to write it in C?

-- 
cheers,
Thorsten

Re: How to define a function in Zile Lisp

[Tassilo Horn]

Thorsten Jolitz <tjolitz@googlemail.com> writes:

Hi Thorsten,

> I recently discovered that the nice small and fast Emacs clone GNU
> Zile (“Zile Is Lossy Emacs”) can be customized in its own .zile file
> with a small subset of Emacs Lisp called Zile Lisp.
>
> ,--------------------------------------------------------------------
> | For customization, Zile uses its own limited configuration language
> | known as Zile Lisp. Zile Lisp is a tiny subset of Emacs Lisp that
> | consists of the Zile commands plus ‘setq’.
> `--------------------------------------------------------------------
>
> How can I define a function (that is at least a sequence of Zile/Emacs
> commands) only with 'setq' and the navigation/editing functions?

You can't.  Zile Lisp is really a very tiny subset of Emacs Lisp.  You
can't do anything except setting some of the few configuration options
like

  (setq tab-width 8)

or calling existing zile commands like

  (global-set-key "\M-hb" 'list-bindings)

Bye,
Tassilo

Re: How to define a function in Zile Lisp

[Thorsten Jolitz]

Tassilo Horn <tsdh@gnu.org> writes:

Hi Tassilo, 

>> How can I define a function (that is at least a sequence of Zile/Emacs
>> commands) only with 'setq' and the navigation/editing functions?
>
> You can't.  Zile Lisp is really a very tiny subset of Emacs Lisp.  You
> can't do anything except setting some of the few configuration options
> like
>
>   (setq tab-width 8)
>
> or calling existing zile commands like
>
>   (global-set-key "\M-hb" 'list-bindings)

too bad, would have been nice to add some functions without knowing C.

How is the Zile Lisp interpreter integrated with Zile? Would it be
possible (and easy) to replace it with another small but at the
same time more powerful Lisp interpreter?

-- 
cheers,
Thorsten

Re: How to define a function in Zile Lisp

[Tassilo Horn]

Thorsten Jolitz <tjolitz@googlemail.com> writes:

Hi Thorsten,

>> You can't.  Zile Lisp is really a very tiny subset of Emacs Lisp.
>> You can't do anything except setting some of the few configuration
>> options like
>>
>>   (setq tab-width 8)
>>
>> or calling existing zile commands like
>>
>>   (global-set-key "\M-hb" 'list-bindings)
>
> too bad, would have been nice to add some functions without knowing C.
>
> How is the Zile Lisp interpreter integrated with Zile? Would it be
> possible (and easy) to replace it with another small but at the
> same time more powerful Lisp interpreter?

As far as I know, GNU Zile has just been ported to Lua, and that version
will probably replace the C version at some point in time.  That is
probably a bit easier to hack on.

It's lisp interpreter (which doesn't implement more than the C version)
is this:

  http://git.savannah.gnu.org/cgit/zile.git/tree/src/lisp.lua?h=lua

Bye,
Tassilo

Re: How to define a function in Zile Lisp

[Aurélien Aptel]

On Tue, Nov 13, 2012 at 6:59 PM, Tassilo Horn <tsdh@gnu.org> wrote:
> As far as I know, GNU Zile has just been ported to Lua, and that version
> will probably replace the C version at some point in time.  That is
> probably a bit easier to hack on.
>
> It's lisp interpreter (which doesn't implement more than the C version)
> is this:
>
>   http://git.savannah.gnu.org/cgit/zile.git/tree/src/lisp.lua?h=lua

That's curious. I'm assuming Zile didn't want a Lisp interpreter
because it would make it less "lightweight". Now that they have a
full-fledged Lua interpreter, is Zile programmable in it? If not, what
is the reason for not having a lisp interpreter ?

Re: How to define a function in Zile Lisp

[Tassilo Horn]

Aurélien Aptel <aurelien.aptel+emacs@gmail.com> writes:

>> As far as I know, GNU Zile has just been ported to Lua, and that
>> version will probably replace the C version at some point in time.
>> That is probably a bit easier to hack on.
>>
>> It's lisp interpreter (which doesn't implement more than the C version)
>> is this:
>>
>>   http://git.savannah.gnu.org/cgit/zile.git/tree/src/lisp.lua?h=lua
>
> That's curious. I'm assuming Zile didn't want a Lisp interpreter
> because it would make it less "lightweight". Now that they have a
> full-fledged Lua interpreter, is Zile programmable in it?

It's written in Lua, so clearly yes.  But I'm not sure if you can have
some ~/.zile.lua (beside the lispy ~/.zile) with your own configs and
settings.  That should be easy to implement, though.

> If not, what is the reason for not having a lisp interpreter ?

I don't know.  Maybe they could have made it extensible using Guile
instead of writing an own suped-tiny lisp interpreter.  But I guess Zile
isn't meant to be overly extensible.  If you want that, go with emacs.

Bye,
Tassilo