Re: Manifesto against Vector

[Vinzent 'Gadget' Hoefler <nntp-2004-05@t-domaingrabbing.de>]

Dmitry A. Kazakov wrote:

>On Thu, 6 May 2004 09:03:54 +0200, "Jean-Pierre Rosen"
><rosen@adalog.fr> wrote:
>
>>Since you asked for it... (but I'll try to have reasonable objections).
>>Note that I am known for being strongly *in favor* of the use clause.
>>
>>I would strongly oppose this proposal for a very simple reason: it
>>defeats the main goal of having separated with from use.
>>With is a library level clause; it tells: "this unit, somewhere needs
>>that unit".
>
>Why that should be told? I'd say that "with" is superfluous.

No! If at all then it is "use" which is superfluous. ;-)

>Maybe, but it should be placed at the beginning of the context. So it
>is just one line difference. Not a big issue, IMO.

It is more than a single line. Consider this:

|with Interfaces;
 ^^^^
|
|package body Timer is
|
[...]
|   function Hi_Byte (Value : in Interfaces.Unsigned_16)
|     return Interfaces.Unsigned_8 is
|      use type Interfaces.Unsigned_16;
       ^^^
|   begin
|      return Interfaces.Unsigned_8 (
|          Interfaces.Shift_Right (Value, 8) and 16#FF#);
|   end Hi_Byte;

>This might work with bodies, but it does not with specifications.

Well, most of it does.

The only part where I used "use" yet was in the private part of a
package spec, and this was just because I am lazy and wanted to have
"System.Storage_Elements.To_Address" visible there as the simpler
"To_Address". I could have used "renames" instead, I guess.

>with Foo;
>procedure P (<something here needs visibility of Foo>);

Simple: Use the full name there. If it's too long for you, I'd say
rename it.

>>Allowing with/use would simply encourage a style that should be
>>discouraged altogether. QED.
>
>Oh, Use is Use, and With is With, and never the twain shall meet, ...
>(:-))

It's much more simple: Never use "use". :)


Vinzent.