Re: [Chicken-users] macro systems and chicken (long)

[Alaric Snell-Pym]

On 4 Apr 2008, at 12:56 pm, Alex Shinn wrote:
> There seems to be a lot of confusion in the Chicken
> community, and the Lisp community in general, about the
> different macro systems, so I thought provide some
> background information and discussion of the eggs available
> in Chicken and their uses.

*applause*

Alex, can we put this on the Wiki for prosperity? It's very useful!

>  On the other hand, if you don't tightly bind
> one specific destructuring idiom to your macro system, you
> can take your pick of any external matching or
> syntax-verifying libraries you want (e.g. use explicit
> renaming macros with the MATCH macro for destructuring).

Yes! This is my biggest beef with syntax-case. We have match - why
not just do things in a way that works with that existing technology,
rather than having these funny syntax objects that need their own
matching system? Duplication sucks.

Syntax-rules is handy for simple stuff, but I'd hate for it to be the
only macro system I had - I like to think of it as a shorthand for a
reasonably common case, TBH. While grumbling slightly about it having
its own destructuring language all over again, and never quite
remembering the rules for ellipses, and thus all too often tending to
just go and use a define-macro since it's not another egg to depend
on and I'd just have to look up the syntax-rules syntax again since,
sure enough, last time I avoided using it anyway, so I never really
get to properly learn the syntax...

...but I'm just lazy ;-) I think I'm going to bite the bullet and
install riaxpander and use er+match for everything, in the hope that
if enough momentum builds up around that, it'll become the de-facto
standard and there will be no more worries about which macro systems
different eggs use and their incompatibilities.

What are people's feelings about moving it into the core? I know it's
nice to keep it simple, but there's a certain un-simplicity in
defining all the core macros with define-macro to just have them
redefined in terms of a hygienic macro system as soon as it's loaded,
and the chicken macro expander offered up to the garbage collector.
And having define-macro as the only macro system supplied out of the
box does sort of encourage people to use it when they'd really be
better off using something hygienic.

ABS

--
Alaric Snell-Pym
Work: http://www.snell-systems.co.uk/
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