From: Peter Amey <pna@praxis-cs.co.uk>
Subject: Re: Elimination of "use" clauses
Date: 1999/07/13
Date: 1999-07-13T08:48:25+00:00 [thread overview]
Message-ID: <378AFC41.5290E6A0@praxis-cs.co.uk> (raw)
In-Reply-To: 7lj9lb$mos$1@nnrp1.deja.com
Ed Falis wrote:
[snip].
>
> I have to agree (strongly) with this comment. There's little reason these
> days not to use such a browsing capability. This allows you to take
> advantage of the benefit of use clauses: uncluttering the source text so you
> can easily understand it logic and structure. With resolution of references
> a click or two away, there's little excuse for long dotted-notation
> references.
>
> - Ed Falis
> Aonix
>
There seems to be an assumption in parts of this thread that
"dotted.names" = "long.or.unwieldy.dotted.names". I don't think that
this has to be the case as long as package and other identifier names
are chosen so that they read well when put together with dots (exactly
as I hope we would when choosing record and field names). A particular
common area of failure in this respect are "bucket" packages containing
type declarations. For example, if we have:
package BasicTypes is
type SwitchType is (On, Off, Unknown);
type ValveType is (Open, Closed, Unknown);
end BasicTypes;
then variable declarations take the (horrible) form:
X : BasicTypes.ValveType;
Y : BasicTypes.SwitchType;
and expressions using them become (in the absence of use clauses)
become:
if X = BasicTypes.Open and Y = BasicTypes.Off ...
I think this is much better handled by using more, smaller packages
(recognising that switches and valves are different things) thus:
package Switch is
type T is (On, Off, Unknown);
end Switch;
package Valve is
type T is (Open, Closed, Unknown);
end Valve;
which leads to the much nicer declarations:
X : Valve.T;
Y : Switch.T;
and expressions of the form:
if X = Valve.Open and Y = Switch.Off ...
I think it is better to choose names that read nicelty in context than
to use extensive renaming (especially abbreviations) to get round
badly-chosen names. I think this means I agree with Robert about the
need to control the global name space.
regards
Peter
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next prev parent reply other threads:[~1999-07-13 0:00 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-07-01 0:00 Elimination of "use" clauses Dr. Neil C. Audsley
1999-07-01 0:00 ` Samuel T. Harris
1999-07-01 0:00 ` czgrr
1999-07-01 0:00 ` Ted Dennison
1999-07-02 0:00 ` czgrr
1999-07-02 0:00 ` Ted Dennison
1999-07-01 0:00 ` Joe Wisniewski
1999-07-02 0:00 ` Robert Dewar
1999-07-02 0:00 ` Ed Falis
1999-07-03 0:00 ` Joe Wisniewski
1999-07-03 0:00 ` Ed Falis
1999-07-03 0:00 ` Keith Thompson
1999-07-13 0:00 ` Peter Amey [this message]
1999-07-02 0:00 ` Ted Dennison
1999-07-02 0:00 ` Ed Falis
1999-07-02 0:00 ` Robert Dewar
[not found] ` <7ltus1$ah1@dfw-ixnews19.ix.netcom.com>
1999-07-13 0:00 ` Robert A Duff
1999-07-18 0:00 ` Richard D Riehle
1999-07-18 0:00 ` jerry
1999-07-19 0:00 ` Vladimir Olensky
1999-07-20 0:00 ` Richard D Riehle
1999-07-20 0:00 ` Opaque Types (was Elimination of "use" clauses) David C. Hoos, Sr.
1999-07-20 0:00 ` Elimination of "use" clauses jerry
1999-07-18 0:00 ` Dale Stanbrough
1999-07-20 0:00 ` David Kristola
1999-07-20 0:00 ` Richard D Riehle
1999-07-19 0:00 ` Brian Rogoff
1999-07-20 0:00 ` Robert Dewar
1999-07-20 0:00 ` Brian Rogoff
1999-07-21 0:00 ` Ted Dennison
1999-07-21 0:00 ` Robert Dewar
1999-07-21 0:00 ` Robert A Duff
1999-07-21 0:00 ` Robert Dewar
1999-07-21 0:00 ` Brian Rogoff
1999-07-22 0:00 ` Robert Dewar
1999-07-22 0:00 ` Brian Rogoff
1999-07-22 0:00 ` Robert Dewar
1999-07-22 0:00 ` Brian Rogoff
1999-07-21 0:00 ` Robert A Duff
1999-07-21 0:00 ` Michael F. Yoder
1999-07-21 0:00 ` Robert A Duff
1999-07-23 0:00 ` Tucker Taft
1999-08-03 0:00 ` Richard D Riehle
1999-07-19 0:00 ` Ted Dennison
1999-07-19 0:00 ` Tucker Taft
1999-07-19 0:00 ` Ted Dennison
1999-07-02 0:00 ` Stephen Leake
1999-07-02 0:00 ` Samuel T. Harris
1999-07-02 0:00 ` Robert Dewar
1999-07-08 0:00 ` R. Tim Coslet
1999-07-09 0:00 ` Robert Dewar
1999-07-09 0:00 ` tmoran
[not found] ` <7ltl2q$mog$1@nnrp1.deja.com>
1999-07-08 0:00 ` Michael F. Yoder
1999-07-09 0:00 ` Richard D Riehle
1999-07-09 0:00 ` Marin David Condic
1999-07-09 0:00 ` Michael F. Yoder
1999-07-09 0:00 ` Robert Dewar
1999-07-09 0:00 ` Dale Stanbrough
1999-07-12 0:00 ` Robert Dewar
1999-07-12 0:00 ` Ted Dennison
1999-07-09 0:00 ` Michael F. Yoder
1999-07-14 0:00 ` Tucker Taft
1999-07-10 0:00 ` Simon Wright
1999-07-12 0:00 ` Robert Dewar
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