From: Matthew Heaney <matthew_heaney@acm.org>
Subject: Re: Naming of Tagged Types and Associated Packages
Date: 1998/08/05
Date: 1998-08-05T00:00:00+00:00 [thread overview]
Message-ID: <m3d8afn4yx.fsf@mheaney.ni.net> (raw)
In-Reply-To: Ex7H8r.HGq@syd.csa.com.au
nospam@thanks.com.au (Don Harrison) writes:
> I think it's not so much namespaces but the fact that the syntax allows
> you (and the compiler) to easily differentiate variables (entities in
> Eiffel parlance) from types.
>
> Some examples..
>
> 1) Variable declarations:
>
> variable : TYPE
>
> The identifier to the left of the colon is recognised as a variable
> and the one on the right as a type.
But this is true in Ada too. The issue in Ada is that once an
identifier appears in a declaration, it can't appear again in the same
declaration. So the declaration
declare
File : File;
begin
is illegal in Ada, even though the compiler knows that the identifier
on the left denotes an object, and the identifier on the right a type.
The same is true for function invokations (aka "constructors") that
appear in a declaration. The declaration
declare
Top : Integer renames Top (Integer_Stack);
begin
is illegal, because of the name clash between object Top and selector
Top. That's why I usually name selectors Get_xxx, to avoid namespace
conflicts inside a declaration. The declaration
declare
Top : Integer renames Get_Top (Integer_Stack);
begin
is now legal.
I argue that different names should be used for an object and its type
in a declaraion, in order to prevent namespace clashes. I don't think
an expanded name (ie P.T) should be used for this purpose.
I make this argument based on a careful reading of the RM. File_Type is
called that precisely because an object of that type will most likely be
called File.
Had the designers intended for expanded name notation to always be used
for the type in an object declaration, in order to resolve a name clash,
then File_Type would have been named just File.
As much as possible, I like to stick to the naming conventions in the
RM. But this is my model. For others, consistency with RM conventions
isn't a compelling enough argument. Oh, well.
next prev parent reply other threads:[~1998-08-05 0:00 UTC|newest]
Thread overview: 138+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-07-16 0:00 Naming of Tagged Types and Associated Packages taashlo
1998-07-25 0:00 ` Matthew Heaney
1998-07-25 0:00 ` Jean-Pierre Rosen
1998-07-25 0:00 ` Brian Rogoff
1998-07-26 0:00 ` Matthew Heaney
1998-07-26 0:00 ` Matthew Heaney
1998-07-26 0:00 ` nabbasi
1998-07-26 0:00 ` Matthew Heaney
1998-07-26 0:00 ` Robert Dewar
1998-07-27 0:00 ` dennison
1998-07-27 0:00 ` Stephen Leake
1998-07-27 0:00 ` dennison
1998-07-27 0:00 ` Brian Rogoff
1998-07-28 0:00 ` dennison
1998-07-28 0:00 ` Brian Rogoff
1998-07-28 0:00 ` Brian Rogoff
1998-07-29 0:00 ` Matthew Heaney
1998-07-29 0:00 ` Brian Rogoff
1998-07-28 0:00 ` dennison
1998-07-29 0:00 ` Matthew Heaney
1998-07-29 0:00 ` Chris Brand
1998-07-30 0:00 ` Matthew Heaney
1998-07-30 0:00 ` dennison
1998-07-30 0:00 ` Matthew Heaney
1998-07-30 0:00 ` dennison
1998-08-01 0:00 ` Simon Wright
1998-08-02 0:00 ` Matthew Heaney
1998-08-03 0:00 ` dennison
1998-08-03 0:00 ` Matthew Heaney
1998-08-04 0:00 ` dennison
1998-08-04 0:00 ` Jean-Pierre Rosen
1998-08-04 0:00 ` Brian Rogoff
1998-08-05 0:00 ` Don Harrison
1998-08-05 0:00 ` Brian Rogoff
1998-08-07 0:00 ` Don Harrison
1998-08-07 0:00 ` doylep
1998-08-07 0:00 ` Brian Rogoff
1998-08-08 0:00 ` Matthew Heaney
1998-08-10 0:00 ` doylep
1998-08-10 0:00 ` Brian Rogoff
1998-08-10 0:00 ` John Volan
1998-08-10 0:00 ` John Volan
1998-08-11 0:00 ` doylep
1998-08-11 0:00 ` Brian Rogoff
1998-08-13 0:00 ` Robert A Duff
1998-08-13 0:00 ` Brian Rogoff
1998-09-01 0:00 ` Matthew Heaney
1998-09-01 0:00 ` Dale Stanbrough
1998-09-01 0:00 ` Matthew Heaney
1998-09-01 0:00 ` Bob Collins
1998-09-02 0:00 ` Matthew Heaney
1998-09-04 0:00 ` John G. Volan
1998-08-11 0:00 ` Don Harrison
1998-08-11 0:00 ` Pat Rogers
1998-08-11 0:00 ` Don Harrison
1998-09-01 0:00 ` Matthew Heaney
1998-08-13 0:00 ` Robert A Duff
1998-08-13 0:00 ` Brian Rogoff
1998-08-15 0:00 ` Don Harrison
1998-08-15 0:00 ` Jean-Pierre Rosen
1998-08-18 0:00 ` Don Harrison
1998-08-14 0:00 ` Don Harrison
1998-08-17 0:00 ` doylep
1998-08-19 0:00 ` Don Harrison
1998-08-12 0:00 ` Don Harrison
1998-08-08 0:00 ` Matthew Heaney
1998-08-08 0:00 ` John G. Volan
1998-08-09 0:00 ` Matthew Heaney
1998-08-10 0:00 ` John G. Volan
1998-08-11 0:00 ` Don Harrison
1998-08-11 0:00 ` geoff
1998-08-11 0:00 ` John Volan
1998-08-31 0:00 ` Matthew Heaney
1998-08-31 0:00 ` Tucker Taft
1998-09-06 0:00 ` John G. Volan
1998-09-06 0:00 ` Matthew Heaney
1998-09-04 0:00 ` John G. Volan
1998-09-06 0:00 ` Matthew Heaney
1998-09-06 0:00 ` John G. Volan
1998-09-06 0:00 ` John G. Volan
1998-09-06 0:00 ` Brian Rogoff
1998-09-06 0:00 ` John G. Volan
1998-09-07 0:00 ` Brian Rogoff
1998-09-07 0:00 ` John G. Volan
1998-09-16 0:00 ` Matthew Heaney
1998-09-04 0:00 ` John G. Volan
1998-09-05 0:00 ` John G. Volan
1998-09-06 0:00 ` Matthew Heaney
1998-09-06 0:00 ` Matthew Heaney
1998-09-04 0:00 ` John G. Volan
1998-09-05 0:00 ` Matthew Heaney
1998-09-05 0:00 ` John G. Volan
1998-09-05 0:00 ` John G. Volan
1998-09-05 0:00 ` John G. Volan
1998-08-11 0:00 ` doylep
1998-08-05 0:00 ` Matthew Heaney [this message]
1998-08-07 0:00 ` Don Harrison
1998-08-13 0:00 ` Robert A Duff
1998-08-14 0:00 ` adam
1998-08-14 0:00 ` Don Harrison
1998-08-05 0:00 ` Static Polymorphism (Was Re: Naming of Tagged Types...) Brian Rogoff
1998-08-06 0:00 ` Matthew Heaney
1998-08-06 0:00 ` Brian Rogoff
1998-07-28 0:00 ` Naming of Tagged Types and Associated Packages Norman H. Cohen
1998-07-28 0:00 ` Matthew Heaney
1998-07-28 0:00 ` Stephen Leake
1998-07-28 0:00 ` Matthew Heaney
1998-07-28 0:00 ` Jean-Pierre Rosen
1998-07-28 0:00 ` Matthew Heaney
1998-07-28 0:00 ` dennison
1998-07-29 0:00 ` Matthew Heaney
1998-07-30 0:00 ` Robert Dewar
1998-07-30 0:00 ` Matthew Heaney
1998-08-06 0:00 ` Robert A Duff
1998-08-06 0:00 ` Matthew Heaney
1998-08-06 0:00 ` Tucker Taft
1998-08-31 0:00 ` Matthew Heaney
1998-07-27 0:00 ` Jean-Pierre Rosen
1998-07-28 0:00 ` Matthew Heaney
1998-07-28 0:00 ` Jean-Pierre Rosen
1998-07-28 0:00 ` dennison
1998-07-29 0:00 ` Jean-Pierre Rosen
1998-07-29 0:00 ` dennison
1998-07-29 0:00 ` Jean-Pierre Rosen
1998-07-30 0:00 ` dennison
1998-07-30 0:00 ` Jean-Pierre Rosen
1998-07-29 0:00 ` Robert I. Eachus
1998-07-30 0:00 ` Matthew Heaney
1998-07-30 0:00 ` Jean-Pierre Rosen
1998-07-30 0:00 ` Robert I. Eachus
1998-07-31 0:00 ` Jean-Pierre Rosen
1998-07-31 0:00 ` Robert I. Eachus
1998-08-01 0:00 ` Jean-Pierre Rosen
1998-08-04 0:00 ` Matthew Heaney
1998-08-04 0:00 ` Jean-Pierre Rosen
1998-08-10 0:00 ` Robert I. Eachus
-- strict thread matches above, loose matches on Subject: below --
1998-07-26 0:00 tmoran
1998-07-27 0:00 ` dennison
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