[Mono-list] Making a ruby.net compiler

Don Syme dsyme@microsoft.com
Mon, 12 May 2003 12:50:04 +0100

I'm not on the Mono list, but Fergus cc'd me on this. =20

ILX discriminated unions should certainly allow the subsequent elements
to be named: it's one of the things I haven't got around to doing
properly yet.  F# will one day also allow them to be optionally named -
you need this if only to get a truly decent quality set of accessors to
the datatype from other .NET languages.

BTW if you're interested in using F# on Mono and/or SSCLI then please
drop me an email.  I'll put together a binary release of the compiler at
some point suitable for use on these platforms, and a source release
will make its way out at some point too.

Cheers & thanks,

-----Original Message-----
From: Fergus Henderson [mailto:fjh@ceres.cs.mu.OZ.AU] On Behalf Of
Fergus Henderson
Sent: 12 May 2003 10:29
To: Mono List
Cc: Don Syme
Subject: Re: [Mono-list] Making a ruby.net compiler

On 11-May-2003, Michal Moskal <malekith@pld-linux.org> wrote:
> 3. if you are familiar with ILX, you should remember .classunion type
>    there, that just did discriminating unions.


> But I believe it isn't very good idea to put it in Mono, since it's
> very limited (namely it seems to fit OCaml variants, but not SML
> variants (things after of can have names)

I agree that fields of discriminated union alternatives should be
many languages which support discriminated unions, including Mercury,
Haskell, and Ada, allow or even require them to be named.

> or OCaml polymorphic=20
> variants (one polymorphic variant can be in several types)).

That's true, but how many other languages have OCaml-style polymorphic

Ordinary discriminated unions are present in a very large number of
languages, so the benefits for language interoperability of including
them in the underlying runtime are much higher.  Also, I suspect that
there is more scope for optimizing the representation of ordinary
discriminated unions.

Fergus Henderson <fjh@cs.mu.oz.au>  |  "I have always known that the
The University of Melbourne         |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S.