

First draft of R7RS (Scheme) small language available - pdelgallego
https://groups.google.com/d/topic/comp.lang.scheme/MCfPoeir90s/discussion

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dhume
_Apologies if you receive multiple copies of this message._

Like the other one still on the front page?

<http://news.ycombinator.com/item?id=2453832>

~~~
Ixiaus
That is a standard preface for many lists that get a lot of crossposts. You'll
see it a lot on most academic mailing lists where conferences and papers are
announced and crossposted to many similar lists that receivers may be
subscribed to.

~~~
dhume
I'm aware of its use as a courtesy to the readers. I was amused to see it on
something that got posted here multiple times and hoped to let everyone else
in on the joke.

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anon_d
_The case-folding behavior of the reader can now be explicitly controlled._

Meh.

 _Module System_

Is there a discussion of this somewhere? Why this style of module system?

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muyuu
Summary :
[https://groups.google.com/forum/#!topic/comp.lang.scheme/MCf...](https://groups.google.com/forum/#!topic/comp.lang.scheme/MCfPoeir90s/discussion)

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cypherpunks
What's wrong with R5RS?

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kbob
Nothing's wrong with it; it just doesn't go far enough.

It doesn't define a standard module system or macros (beyond syntax-rules),
exceptions, or record types. Most R5RS implementations offer those, but
they're all different and incompatible. The standard also doesn't help with
boring but necessary stuff like file encodings, character sets, etc.

So instead of writing a (nontrivial) program for R5RS Scheme, you have to
write it for MIT Scheme or Racket or Chicken or Chibi or ...

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cypherpunks
What's right, though, is you can implement an interpreter in a weekend. That
makes it usable in a lot of places. Once you add exceptions, that goes away.
File encodings and character sets are nice, but short-sited. R5RS was eternal.
No one predicted the move to Unicode 35 years ago when Scheme was created, and
that lack of definition let it make the transition fine.

I'm all for recommendations on things like those, so if you chose to implement
them, there's a standard way, but I'm not in favor of making those part of the
standard.

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chc
Implementing an interpreter for a language in a weekend is a less common need
than writing a program for the language. If you want to write an interpreter
that does no more than R5RS in a weekend, R5RS is perfect for you. But surely
you can see the need for a standard beyond that.

