From: eachus@mitre-bedford.ARPA (Robert Eachus)
Subject: Re: Typing Ada
Date: 26 May 88 14:14:51 GMT [thread overview]
Message-ID: <32982@linus.UUCP> (raw)
In-Reply-To: 2831@Shasta.STANFORD.EDU
[In Memorandum. The line eater, may he rest in peace.]
In article <2831@Shasta.STANFORD.EDU> neff@Shasta.UUCP (Randall Neff) writes:
(Some stuff omitted for brevity)
>
>In Ada, there is only a single hierarchy mechanism, the package; and only
>a single abstraction, the programming language code.
>
To quote the Ada RM:
Packages are one of the four forms of program unit of which
programs can be composed. The other forms are subprograms, task
units, and generic units. Chapter 7, paragraph 1.
All four are heirarchy mechanisms, all four can be used to model
abstractions (although each is most appropriate for a different set of
abstractions). I'm sure Randall's omission of other hierarchy
mechanisms was accidental, but there are many Ada programmers out
there who don't seem to realize that generics and tasks can, and often
should, be used to create abstact data types, so I couldn't let this
just pass by. (Just in case someone decides to pick nits, Ada also
has blocks which can be considered as a heirarchy mechanism. But they
are in general not used in that way, and should be excluded also based
on the sense of Randall's discussion.)
Robert I. Eachus
with STANDARD_DISCLAIMER;
use STANDARD_DISCLAIMER;
function MESSAGE (TEXT: in CLEVER_IDEAS) return BETTER_IDEAS is...
next prev parent reply other threads:[~1988-05-26 14:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
1988-05-10 16:28 Typing Ada Bob Munck
1988-05-24 3:51 ` Rick Conn
1988-05-24 15:32 ` Bob Munck
1988-05-24 23:06 ` Rick Conn
1988-05-25 16:49 ` Eugene N. Miya
1988-05-25 5:53 ` Richard A. O'Keefe
1988-05-25 16:57 ` Randy Neff
1988-05-26 14:14 ` Robert Eachus [this message]
1988-05-26 12:40 ` David Collier-Brown
1988-05-25 13:30 ` Roger Racine
-- strict thread matches above, loose matches on Subject: below --
1988-05-12 17:28 zellich
1988-05-20 12:51 Karl A. Nyberg
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