From: Edgar Friendly <thelema314@gmail.com>
To: Martin Jambon <martin.jambon@ens-lyon.org>
Cc: Alain Frisch <alain@frisch.fr>, caml-list <caml-list@yquem.inria.fr>
Subject: Re: [Caml-list] Compiler feature - useful or not?
Date: Fri, 16 Nov 2007 11:54:30 -0600 [thread overview]
Message-ID: <473DD956.7090608@gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0711161840190.15912@martin.ec.wink.com>
Martin Jambon wrote:
> On Fri, 16 Nov 2007, Edgar Friendly wrote:
>
>> Martin Jambon wrote:
>>> Please don't take my suggestions too seriously, but it could be cool to
>>> define types such as:
>>>
>>> type bit = [ 0 | 1 ]
>>>
>>>
>>> Martin
>>
>> How about this:
>>
>> type permission =
>> User_read -> 0o400 | User_write -> 0o200 | User_execute -> 0o100
>> | Group_read -> 0o40 | Group_write -> 0o20 | Group_execute -> 0o10
>> | World_read -> 0o4 | World_write -> 0o2 | World_execute -> 0o1
>>
>> let combine (pl: permission list) =
>> List.fold_left (fun a b -> a lor (b :> int)) 0 pl
>
> I'm afraid of losing the following basic feature ("your first OCaml
> program"):
>
> # 0;;
> - : int
>
> and instead get:
>
> # 0;;
> - : [< int > 0 ]
>
> Perhaps polymorphism should not be the default, i.e. we would have to
> use a special keyword:
>
> # poly 0;;
> - : [< int > 0 ]
> # 0;;
> - : int
>
Explicit casts, my friend. Explicit casts to convert from int to
permission and back. And automatically generated runtime checks to
ensure that you don't try to convert ( 37 :> permission ). 1 remains an
int, and if you want World_execute (or true or anything else whose
runtime representation is 1), a checked cast becomes necessary.
E.
next prev parent reply other threads:[~2007-11-16 17:54 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-13 23:41 Edgar Friendly
2007-11-14 0:08 ` [Caml-list] " Yaron Minsky
2007-11-14 0:21 ` Martin Jambon
2007-11-14 7:58 ` Pierre Weis
2007-11-14 12:37 ` Alain Frisch
2007-11-14 13:56 ` Virgile Prevosto
2007-11-14 14:35 ` Pierre Weis
2007-11-14 16:38 ` Alain Frisch
2007-11-14 18:43 ` Pierre Weis
2007-11-14 19:19 ` Edgar Friendly
2007-11-15 6:29 ` Alain Frisch
2007-11-15 13:26 ` Pierre Weis
2007-11-15 17:29 ` Edgar Friendly
2007-11-15 20:28 ` Fernando Alegre
2007-11-16 0:47 ` Brian Hurt
2007-11-15 22:37 ` Michaël Le Barbier
2007-11-15 22:24 ` Michaël Le Barbier
2007-11-16 0:30 ` Yaron Minsky
2007-11-16 1:51 ` Martin Jambon
2007-11-16 9:23 ` Alain Frisch
2007-11-16 14:17 ` rossberg
2007-11-16 15:08 ` Martin Jambon
2007-11-16 16:43 ` Martin Jambon
2007-11-16 16:46 ` Till Varoquaux
2007-11-16 17:27 ` Edgar Friendly
2007-11-16 17:47 ` Martin Jambon
2007-11-16 17:54 ` Edgar Friendly [this message]
2007-11-16 18:10 ` Fernando Alegre
2007-11-16 19:18 ` David Allsopp
2007-11-16 19:32 ` Fernando Alegre
2007-11-16 19:50 ` Gerd Stolpmann
2007-11-16 17:31 ` Fernando Alegre
2007-11-16 17:43 ` Edgar Friendly
2007-11-16 0:46 ` Christophe TROESTLER
2007-11-16 8:23 ` Andrej Bauer
2007-11-16 8:58 ` Jean-Christophe Filliâtre
2007-11-16 9:13 ` Andrej Bauer
2007-11-16 9:48 ` Christophe TROESTLER
2007-11-14 16:57 ` Edgar Friendly
2007-11-14 21:04 ` Pierre Weis
2007-11-14 22:09 ` Edgar Friendly
2007-11-15 0:17 ` Jacques Garrigue
2007-11-15 6:23 ` Edgar Friendly
2007-11-15 10:53 ` Vincent Hanquez
2007-11-15 13:48 ` Jacques Carette
2007-11-15 14:43 ` Jon Harrop
2007-11-15 16:54 ` Martin Jambon
2007-11-14 16:09 ` Edgar Friendly
2007-11-14 16:20 ` Brian Hurt
2007-11-14 11:01 ` Gerd Stolpmann
2007-11-14 10:57 ` Jon Harrop
2007-11-14 14:37 ` Zheng Li
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=473DD956.7090608@gmail.com \
--to=thelema314@gmail.com \
--cc=alain@frisch.fr \
--cc=caml-list@yquem.inria.fr \
--cc=martin.jambon@ens-lyon.org \
/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).