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Last call for comments on SRFI 172: Two Safer Subsets of R7RS Arthur A. Gleckler (02 Sep 2019 04:28 UTC)
Evaluating definitions Lassi Kortela (02 Sep 2019 07:38 UTC)
Re: Evaluating definitions John Cowan (20 Oct 2019 22:11 UTC)
Re: Evaluating definitions Marc Nieper-Wißkirchen (21 Oct 2019 06:37 UTC)
Re: Evaluating definitions John Cowan (21 Oct 2019 16:51 UTC)
Re: Last call for comments on SRFI 172: Two Safer Subsets of R7RS Marc Nieper-Wißkirchen (02 Sep 2019 08:46 UTC)
Re: Last call for comments on SRFI 172: Two Safer Subsets of R7RS Marc Nieper-Wißkirchen (02 Sep 2019 09:09 UTC)

Re: Last call for comments on SRFI 172: Two Safer Subsets of R7RS Marc Nieper-Wißkirchen 02 Sep 2019 09:09 UTC

Am Mo., 2. Sept. 2019 um 10:57 Uhr schrieb Lassi Kortela <xxxxxx@lassi.io>:
>
> > 2) If a Scheme system supports reader macros (e.g. Racket), the `read'
> > procedure should be considered unsafe; thus, it may be best to remove
> > it from (srfi 172) and (srfi 172 functional).
>
> Would it be possible to mandate that the SRFI 172 environment provide a
> version of `read` using standard syntax with no extensions?

The same should probably hold for all other potentially dangerous
procedures. This can work if my point 1) is incorporated into SRFI
172.

However, it will mean that SRFI 172 cannot have a portable implementation.

>
> What about custom writers for user-defined data types? Common Lisp lets
> users specialize the `print-object` method for their own types; some
> Scheme probably has something similar, or will eventually.
>
> Is `read` useful in the environment? `write` probably is, but could we
> make do with just `write-char`, `write-string`, `write-u8` and
> `write-bytevector`? There's `number->string` and `symbol->string` for
> the most frequently needed conversions.

The difference to `read' seems to be that the code evaluated under
SRFI 172 cannot easily register custom writers.

-- Marc