Re: Objective-C - Smalltalk bridge

[Marcel Weiher]

On 21 May 2005, at 23:51, Nicolas Roard wrote:

> > What is Objective-Smalltalk?  In a nutshell:  a Smalltalk syntax  
> > for the Objective-C runtime + language semantics.  So there are no  
> > proxies and no two runtimes that have to talk to each other.  This  
> > allows Objective-ST to be very compact, currently only around 1.5  
> > KLOC, with several hundred of those being the unit tests.  That  
> > includes a basic compiler/interpreter (compiler for the syntax,  
> > 'interpreter' for running the returned Objective-C objects that  
> > represent a script/method) ready for integration.  It is still  
> > early days, but good enough to use in some of my shipping products.
>
> is it possible to play with it already ? else, any release planned  
> soon ? and what licence do you think you will use ?

I find it quite playable, but haven't released anything yet.  I do  
want to open it up as soon as possible, because one of Objective- 
Smalltalk's primary goal is to be adaptable for a wide variety of  
contexts, and the only way to do that is for people to use it in  
different contexts.

For example, awk's dispatch mechanism is really quite similar to OO  
dispatch, except that OO dispatches on a fixed string, whereas awk  
dispatches on a string pattern.  I wouldn't want to add that to an OO  
language, but 'subclassing' the language for that specific  
circumstance sounds just fine...


> > Another part:  stsh, a smalltalk shell, both for interactive and  
> > scripting use.
>
> that's really interesting :-) -- now I want it :-D

:-D

With NSDecimalNumbers set as default number literals, stsh also makes  
for a fairly decent 'dc' replacement, at least for my modest needs.

I've wanted an OO shell for quite some time...and had it for a while  
when bbum created the WebScript shell.  Very, very useful, but  
WebScript was closed source, only available with WO and then went  
away.  In fact, that was one of the motivations for Objective- 
Smalltalk, except that on thinking about it, it didn't seem to make  
much sense to create an interpreter for Objective-C, when all that I  
was really interested in was the Objective- side.

Anyway, one direction I'd also like to see is stsh used as a true sh/ 
bash/csh/zsh/... replacement.  This has also been on my mind for some  
time, and it really annoys me that MS now seems to have beat me to it:

     http://weblog.infoworld.com/udell/2004/11/02.html#a1106
     http://www.eweek.com/article2/0,4149,1550180,00.asp
     http://dotnetjunkies.com/WebLog/stefandemetz/archive/ 
2004/04/20/11794.aspx

However, I still think we can do a better job.


> > In the works:  a gcc front end, though that is *quite* a  
> > struggle.  Doing a JIT might be simpler... :-(
>
> another question though, do you have a garbage collector ? Hm... I  
> guess there's probably no GC, as in fact Objective-Smalltalk just
> provides a different "syntax" to access the objc runtime ?

You guessed right:  SEP! :-)


> Ah, and how tied is it to the NeXT runtime (apparently, it runs on  
> OSX, not on GNUstep) ?

Not much at all.  The ObjC -> ST method interfaces may require a bit  
of tweaking, but dispatch is currently handled via NSInvocation and  
should therefore port OK (though a move away from NSInvocation is  
desirable).

Regards,

Marcel