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Generic interfaces Daphne Preston-Kendal (23 Jul 2021 11:34 UTC)
Re: Generic interfaces Lassi Kortela (23 Jul 2021 11:48 UTC)
Against hierarchy Lassi Kortela (23 Jul 2021 11:56 UTC)
Re: Against hierarchy Marc Nieper-Wißkirchen (23 Jul 2021 12:04 UTC)
Re: Against hierarchy Lassi Kortela (23 Jul 2021 12:08 UTC)
Re: Against hierarchy Marc Nieper-Wißkirchen (23 Jul 2021 12:26 UTC)
R6RS exception hierarchy Lassi Kortela (23 Jul 2021 12:39 UTC)
Re: R6RS exception hierarchy Marc Nieper-Wißkirchen (23 Jul 2021 13:09 UTC)
Re: R6RS exception hierarchy Lassi Kortela (23 Jul 2021 16:05 UTC)
Re: R6RS exception hierarchy Marc Nieper-Wißkirchen (23 Jul 2021 16:24 UTC)
Re: R6RS exception hierarchy Arthur A. Gleckler (23 Jul 2021 17:19 UTC)
Re: R6RS exception hierarchy Marc Nieper-Wißkirchen (23 Jul 2021 17:49 UTC)
Re: R6RS exception hierarchy Arthur A. Gleckler (23 Jul 2021 19:28 UTC)
Re: R6RS exception hierarchy John Cowan (26 Jul 2021 21:32 UTC)
Re: R6RS exception hierarchy Marc Nieper-Wißkirchen (27 Jul 2021 05:46 UTC)
Re: Generic interfaces Daphne Preston-Kendal (23 Jul 2021 17:47 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (23 Jul 2021 18:17 UTC)
Re: Generic interfaces Adam Nelson (23 Jul 2021 18:55 UTC)
Re: Generic interfaces Per Bothner (24 Jul 2021 19:31 UTC)
Re: Generic interfaces John Cowan (24 Jul 2021 04:27 UTC)
Re: Generic interfaces John Cowan (24 Jul 2021 04:26 UTC)
Re: Generic interfaces Daphne Preston-Kendal (25 Jul 2021 09:08 UTC)
Re: Generic interfaces Amirouche (25 Jul 2021 14:36 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (23 Jul 2021 12:18 UTC)
Re: Generic interfaces Daphne Preston-Kendal (23 Jul 2021 17:49 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (23 Jul 2021 17:51 UTC)
Re: Generic interfaces Daphne Preston-Kendal (23 Jul 2021 18:12 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (23 Jul 2021 18:39 UTC)
Re: Generic interfaces John Cowan (24 Jul 2021 03:56 UTC)
Re: Generic interfaces John Cowan (24 Jul 2021 02:22 UTC)
Re: Generic interfaces Jeremy Steward (24 Jul 2021 03:38 UTC)
Re: Generic interfaces Amirouche (25 Jul 2021 06:19 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (25 Jul 2021 08:39 UTC)
Re: Generic interfaces Daphne Preston-Kendal (25 Jul 2021 09:28 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (25 Jul 2021 10:04 UTC)
Re: Generic interfaces Daphne Preston-Kendal (25 Jul 2021 10:47 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (25 Jul 2021 12:16 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (29 Jul 2021 08:18 UTC)
Re: Generic interfaces John Cowan (26 Jul 2021 00:04 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (26 Jul 2021 06:25 UTC)
Re: Generic interfaces John Cowan (26 Jul 2021 12:26 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (26 Jul 2021 13:00 UTC)
Re: Generic interfaces Ray Dillinger (26 Jul 2021 19:28 UTC)
Re: Generic interfaces John Cowan (26 Jul 2021 19:53 UTC)
Re: Generic interfaces Arthur A. Gleckler (26 Jul 2021 22:15 UTC)
Re: Generic interfaces John Cowan (25 Jul 2021 23:37 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (26 Jul 2021 06:10 UTC)
Re: Generic interfaces John Cowan (26 Jul 2021 11:43 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (26 Jul 2021 12:09 UTC)
Re: Generic interfaces John Cowan (26 Jul 2021 13:14 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (26 Jul 2021 13:37 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (16 Nov 2021 18:52 UTC)
Re: Generic interfaces John Cowan (25 Jul 2021 23:00 UTC)
Re: Generic interfaces Marc Nieper-Wißkirchen (26 Jul 2021 05:44 UTC)

Against hierarchy Lassi Kortela 23 Jul 2021 11:56 UTC

Related note: it's becoming increasingly clear that we keep running into
problems with hierarchies. The exception hierarchy (R6RS vs others) is
the most obvious example. Much of the discussion around the withdrawn
SRFI 198 was around how (if at all) to do hierarchies, and if there are
two hierarchies, how to decide which one is authoritative.

We can solve all problems like this if standard Scheme is silent on all
matters of hierarchy. Instead, we could simply talk about set
membership. Any proposal that needs to classify objects, simply provides
predicate procedures for the sets it cares about.

This means that something like `file-error?` in proposal A can be
different from `file-error?` in proposal B. If these predicates are
imported from libraries, each Scheme program can import the predicates
it wants and ignore others.

In some scenarios we want to interface standard Scheme to existing
object systems, and probably to ML-style type systems in the future.
These targets are inherently hierarchical, so it's an open question how
to that.