Re: Clause "with and use"

[18k11tm001@sneakemail.com (Russ)]

Gautier Write-only <gautier@fakeaddress.nil> wrote in message news:<3FAAB12E.C7593B45@fakeaddress.nil>...
> > Hyman Rosen:
> 
> [...]
> > > for an example of the latter form. It contains
> > >     with ADA.TEXT_IO, ADA.CALENDAR, ADA.CHARACTERS.LATIN_1;
> > >     use  ADA.TEXT_IO, ADA.CHARACTERS.LATIN_1;
> > >
> > > So upon seeing a with/use pair, I have to read it carefully to
> > > see if the two lists are the same, and if they are not, try to
> > > figure out why that may be.
> 
> Warren W. Gay VE3WWG:
> > The other problem is that you don't always want to "use"
> > every with. Consider [...]
> 
> It is exactly what the author of the above code wanted,
> not to "use" ADA.CALENDAR. *This* would be a lot clearer if only
> 
> with ADA.CALENDAR;
> use ADA.TEXT_IO, ADA.CHARACTERS.LATIN_1;
> 
> was sufficient (this is the "implicit 'with'" variant) - or
> 
> with ADA.CALENDAR;
> with and use ADA.TEXT_IO, ADA.CHARACTERS.LATIN_1;
> 
> And the list can be long in *certain* programs, *not* the
> safety-critical code or whatever "special" code where
> anyway an Ada subset without "use" at all is preferable,
> *but* the "everyday programming" where some general-purpose
> packages for
>   - the Text_IO stuff
>   - the Floating-point maths
>   - GUI stuff
> are obviously better to be "use"-d at the unit level.
> And this is still a *minority* of packages, the other ones,
> specialized, would be of course only "with"ed by normal persons.
> 
> All that is a question of style, project, taste, security,
> about the usage of "use", which is already in the language.
> The purpose of the proposal is not to reintroduce "use" or
> changing any style rule, but *only* to make the life
> easier and programs clearer when (and only when) we use
> "use" as a context clause.
> The question of desirability of "use" in such or such context
> or for such or such package is *another* problem - and sorry,
> "use" exists, it won't be removed, but if one wants one can
> avoid it, at worst with a language subset, and it won't hurt
> anybody.
> 
> The whole debate has (as expected ;-) shifted from
> "how to make use-as-a-context-clause easier"
> to
> "to use or not to use"
> or even
> "to += or not to +=".
> Please (dear participants) remain on-topic...

I'm with you on this one. Whether it's "with and use," with/use", or
simply "use" (as context clause) implies "with" (my preference), I
just don't see any rational argument against it. Programmers would
still be able to use "with" and "use" exactly as they do now.

You've heard of a "tin ear", but I think it takes a "tin eye" to
insist on repetitive "with" and "use" for things like basic I/O. Try
to imagine how many potential Ada users are turned off by such
clutter.

By the way, I am not the one who introduced "+=" on this thread. I
merely replied to someone else's offhand remark.