From: nr@labrador.cs.virginia.edu (Norman Ramsey)
Subject: How to write TYPECASE in Ada 95?
Date: 1999/02/05
Date: 1999-02-05T00:00:00+00:00 [thread overview]
Message-ID: <79fct8$9k3$1@murdoch.acc.Virginia.EDU> (raw)
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
type Point is tagged
record
X, Y : Real := 0.0;
end record;
type Painted_Point is new Point with
record
Paint : Color := White;
end record;
type Tall_Point is new Point with
record
Height : Real := 0.0;
end record;
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?
Norman
--
Norman Ramsey
http://www.cs.virginia.edu/~nr
next reply other threads:[~1999-02-05 0:00 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-02-05 0:00 Norman Ramsey [this message]
1999-02-05 0:00 ` How to write TYPECASE in Ada 95? 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
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 ` 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
1999-02-19 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 ` (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
1999-02-24 0:00 ` Samuel T. Harris
1999-02-24 0:00 ` Matthew Heaney
1999-02-24 0:00 ` Tucker Taft
1999-02-06 0:00 ` How to write TYPECASE in Ada 95? Matthew Heaney
1999-02-06 0:00 ` 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.
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