From: Yotam Barnoy <yotambarnoy@gmail.com>
To: Ocaml Mailing List <caml-list@inria.fr>
Subject: [Caml-list] Expanding functors
Date: Thu, 27 Aug 2015 09:29:54 -0400 [thread overview]
Message-ID: <CAN6ygOkt00dsKkZPvKybbeHa-yw_s7tKC2LwHPGcRPDCUBz51Q@mail.gmail.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 955 bytes --]
One problem I've commonly encountered in OCaml is the inability to expand
the interface of functors after they've been created (I'm not talking about
post-application). For example, Map.Make in the stdlib takes an OrderedType
module which contains only the compare function. What happens if I want to
add something to this interface, such as a show function? I have to copy
the whole implementation of Map.Make into my own file to modify it. Compare
this to the ability to 'include' a regular module and just add the new
functionality, and to take the type of a module and expand that type as
needed. Functors are severely lacking in this regard.
What do people think of this idea -- of allowing functors to be expanded?
Ideally, expanding a functor would allow for both replacing its argument
type (as in the example I gave) and for adding a second/third functor
argument type (so Map.Make(OrderedType) would become
Map.Make(OrderedType)(Show).
-Yotam
[-- Attachment #2: Type: text/html, Size: 1058 bytes --]
next reply other threads:[~2015-08-27 13:30 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-27 13:29 Yotam Barnoy [this message]
2015-08-27 13:33 ` Drup
2015-08-27 13:35 ` Gabriel Scherer
2015-08-27 14:17 ` Yotam Barnoy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAN6ygOkt00dsKkZPvKybbeHa-yw_s7tKC2LwHPGcRPDCUBz51Q@mail.gmail.com \
--to=yotambarnoy@gmail.com \
--cc=caml-list@inria.fr \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).