Taylan Ulrich Bayırlı/Kammer scripsit:

> I think it would be very useful to specify external representation
> (reader syntax) for hash tables, but I want to make sure I'm not adding
> anything unreasonable to the spec.  External representation is a big
> deal since it changes the lexical syntax.

I think it's very important, if you are going to add lexical syntax,
to comply with SRFI-108.  It doesn't have a lot of coverage yet beyond
Kawa, but it is the first mechanism for extending Scheme lexical syntax
(always excepting Racket) that doesn't suffer from phasing problems.
Its downside is that it doesn't work like you expect in data files read
with `read`, but how common are those these days?

If you decide to do that, then all you have to do is pick a set of tags
like your `hash`, `hashq`, and `hashv` and explain the meaning of the
identifiers `$construct$:hash` etc. (which can be procedures or macros).
That way you don't need a separate SRFI, and people with SRFI-108 can
just use:

> &hashq{(key . value) ...}  ; eq? based
> &hashv{(key . value) ...}  ; eqv? based
> &hash{(key . value) ...}  ; equal-hash & equal? based

etc.

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
I am expressing my opinion.  When my honorable and gallant friend is
called, he will express his opinion.  This is the process which we
call Debate.                   --Winston Churchill