From: Jacques Garrigue <garrigue@math.nagoya-u.ac.jp>
To: yminsky@cs.cornell.edu
Cc: caml-list@inria.fr
Subject: Re: [Caml-list] Seemingly inconsistent labels for List module
Date: Sun, 29 May 2005 20:27:40 -0400 (EDT) [thread overview]
Message-ID: <20050529.202740.07649159.garrigue@math.nagoya-u.ac.jp> (raw)
In-Reply-To: <891bd33905052818563ef06063@mail.gmail.com>
From: Yaron Minsky <yminsky@gmail.com>
> I've noticed what appear to be inconsistent labelling on some list
> functions, and I'm wondering if I'm properly understanding the reasons
> behind the way the labels work.
>
> For example, in the various association list functions, in some cases
> the association list is passed with a ~map label, and sometimes with
> no label. Another odd case is the mem and memq functions, both of
> which label the list being queried with the label ~set. In this case,
> the labelling mostly seems kind of useless rather than inconsistent.
There are reasons for both :-)
The ~set label is there, so that you can easily define the membership
function.
let in_a = List.mem ~set:a
Same thing for ~map in List.mem_assoc.
However, there is no label in List.remove_assoc, because there it
doesn't really make sense: it maps an association list to a new
association list.
There is no label either in List.assoc for a dirty reason:
as the result is a polymorphic variable, if there were a label, one
wouldn't be able to omit it in applications. List.assoc is used very
often.
> I'm asking all of this because I'm playing around with writing a
> labelled version of the extlib interface, and I'm wondering whether
> these are mistakes that should be fixed, or whether there are good
> reasons for them and they should be preserved.
So, there are good reasons, but you may make different choices. The
labelling of the standard library is intentionally light; in other
libraries you might want to put more. Or, conversely, if you choose to
have only a labelled version (avoids maintaining two versions), you
must be careful of using labels only where they will not get in the
way.
Jacques Garrigue
prev parent reply other threads:[~2005-05-30 0:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-29 1:56 Yaron Minsky
2005-05-30 0:27 ` Jacques Garrigue [this message]
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=20050529.202740.07649159.garrigue@math.nagoya-u.ac.jp \
--to=garrigue@math.nagoya-u.ac.jp \
--cc=caml-list@inria.fr \
--cc=yminsky@cs.cornell.edu \
/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).