From: falis@ma.aonix.com (Ed Falis)
Subject: Re: How to write TYPECASE in Ada 95?
Date: 1999/02/06
Date: 1999-02-06T00:00:00+00:00 [thread overview]
Message-ID: <1103_918264881@DZOG-CHEN> (raw)
In-Reply-To: Pine.BSF.4.05.9902051123560.3807-100000@shell5.ba.best.com
> On 5 Feb 1999, Norman Ramsey wrote:
> >
> > I'm trying to figure out from the reference manual how to identify
> > which type extension of a type I have. For example, if I have
> >
>
> > I'd like to be able to discriminate at run time:
> >
> > p : Point;
> >
> > ...
> >
> > if p in Painted_Point then
> > ... do something with Painted_Point'(p)
> > else if p in Tall_Point then
> > ... do something with Tall_Point'(p)
> >
> > Even better would be something like Modula-3 TYPECASE:
> >
> > (* modula-3 *)
> > TYPECASE p OF
> > Painted_Point (painted) => ... do something with painted
> > Tall_Point (tail) => ... do something with tall
> > ...
> > END
> >
> > What's the idiomatic way to express this in Ada?
I thought a good part of the point of tagged types (and support for polymorphism in other OOP's) was exactly to avoid this kind of code.
- Ed
next prev parent reply other threads:[~1999-02-06 0:00 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-02-05 0:00 How to write TYPECASE in Ada 95? Norman Ramsey
1999-02-05 0:00 ` Brian Rogoff
1999-02-05 0:00 ` David C. Hoos, Sr.
1999-02-05 0:00 ` Brian Rogoff
1999-02-06 0:00 ` Ed Falis [this message]
1999-02-06 0:00 ` Nick Roberts
1999-02-06 0:00 ` Nick Roberts
1999-02-17 0:00 ` Tom Moran
1999-02-18 0:00 ` Matthew Heaney
1999-02-18 0:00 ` Tom Moran
1999-02-18 0:00 ` robert_dewar
1999-02-19 0:00 ` Nick Roberts
1999-02-19 0:00 ` Tom Moran
1999-02-18 0:00 ` Tom Moran
1999-02-18 0:00 ` Matthew Heaney
1999-02-19 0:00 ` Tom Moran
1999-02-19 0:00 ` Tom Moran
1999-02-23 0:00 ` Samuel Mize
1999-02-23 0:00 ` Question (was Re: How to write TYPECASE in Ada 95?) Mike Silva
1999-02-24 0:00 ` Samuel T. Harris
1999-02-24 0:00 ` Matthew Heaney
1999-02-24 0:00 ` Tucker Taft
1999-02-24 0:00 ` (long) programming by extension (was: " Samuel Mize
1999-02-24 0:00 ` (long) programming by extension Samuel Mize
1999-02-25 0:00 ` (shorter and new) " Samuel Mize
1999-02-25 0:00 ` Mike Silva
1999-02-26 0:00 ` Samuel Mize
1999-02-24 0:00 ` Question (was Re: How to write TYPECASE in Ada 95?) Nick Roberts
1999-02-06 0:00 ` How to write TYPECASE in Ada 95? David C. Hoos, Sr.
1999-02-06 0:00 ` Matthew Heaney
1999-02-06 0:00 ` Matthew Heaney
1999-02-06 0:00 ` Matthew Heaney
1999-02-09 0:00 ` David C. Hoos, Sr.
1999-02-06 0:00 ` Matthew Heaney
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox