From: "AG" <ang@xtra.co.nz>
Subject: Re: Ranges and discriminant constraints
Date: Sun, 8 Jun 2003 19:21:23 +1200
Date: 2003-06-08T19:21:23+12:00 [thread overview]
Message-ID: <4tBEa.16019$JA5.308000@news.xtra.co.nz> (raw)
In-Reply-To: jYwEa.2963$7l6.2875@fe03.atl2.webusenet.com
"David C. Hoos" <david.c.hoos.sr@ada95.com> wrote in message
news:jYwEa.2963$7l6.2875@fe03.atl2.webusenet.com...
>
> "Vadim Godunko" <vgodunko@vipmail.ru> wrote in message
> news:665e587a.0306071258.1a8711cc@posting.google.com...
> > Hello,
> >
> > Does anybody explain me why language allow constraint discriminant of
> > discrete type to some value, but not allow constraint to range?
>
> To constrain a discrete type to a more narrow range, you use a subrtype --
> e.g.:
>
> type my_enum is (a, b, c, d, e);
>
> subtype my_constrained_enum is my_enum range b .. d;
I think it's a little bit trickier that that. What the guy
asked for is something like:
X (my_enum) -- record
Y my_enum subtype -- some constraint here
Z -- subtype of X with discriminant Y
Short of generics, any better ideas?
prev parent reply other threads:[~2003-06-08 7:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-06-07 20:58 Ranges and discriminant constraints Vadim Godunko
2003-06-07 21:51 ` AG
2003-06-08 6:00 ` Vadim Godunko
2003-06-08 7:45 ` Dmitry A. Kazakov
2003-06-08 2:22 ` David C. Hoos
2003-06-08 7:21 ` AG [this message]
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