Re: is requiring cl bad?

[David De La Harpe Golden]

On 20/12/12 09:16, Helmut Eller wrote:

> Have you actually taken a "hard look" at Ron Garret's lexicons?
> What  was your experience?  I played with them a few years back, but I quickly
> concluded that lexicons are only a crude prototype

Well, the last version I looked much at was ~2.0 when he started to 
reuse packages extensively as part of the underlying implementation 
(something I disliked actually [1], but he saw lexicons as a complete 
replacement for packages, I remember in the CL case I would have 
preferred if they had been independent facilities (but my concerns about 
packages vs. lexicons in the CL cases /would not apply/ here in emacs 
land, because there are no packages))

> and that it was never used in the "field"; not something I
> would use.

Not exactly mature, no - but hey, was new, shrug.  Anyway, there's 
presumably no way at his /implementation/ could be reused for emacs 
unless emacs was first made into a common lisp.

However, I mentioned lexicons as something to look at for inspiration 
for a hypothetical emacs system: the quality of Ron's actual 
implementation for [C]CL is not of particular concern for that purpose, 
in fact you could avoid looking at it completely (though it appears to 
be liberally licensed) and just read the paper for that purpose.

> > Emacs lisp is lexically scoped now after all.
>
> If you want Scheme-like modules based on lexical scoping you will also
> need hygienic macros.  (Something that Common Lisp nicely avoids.)

Ron actually presented lexicons plus an escaping hack as an 
/alternative/ to scheme-style hygienic macros in his paper, mind, you 
may or may not be convinced that's better than a hygienic macro DSL, not 
sure I was.

I figure implementation innards would need amendment regardless in the 
emacs case, practically if not in theory (I didn't mean to suggest 
lexicons be built on top of existing facilities at a purely lisp level 
or something in the emacs case, whereas despite CCL-isms, Ron used 
mostly portable CL)

[1] 
http://coding.derkeiler.com/Archive/Lisp/comp.lang.lisp/2008-12/msg00359.html