Re: Don't use the "use" clause

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Sat, 19 Nov 2005 23:40:46 GMT, Anonymous Coward wrote:

> In article <1ef4kvy6kdkwz.oqmb8acj5joo.dlg@40tude.net>, 
> Dmitry A. Kazakov wrote:
>> 
>> No, name collisions better be prevented by making "use" illegal when
>> it hides anything.
> 
> The use clause is barred by coding standards for a good reason, and I
> don't think it's necessarily name collisions that drive this rule.

What else then?

> Programmers are forced to resolve name collisions, with or without the
> USE clause.

No. Don't refer to conflicting names and the compiler won't object. This is
IMO bad.

> The use clause is banned because it makes code unreadable
> and difficult to use.  As Joel Spolsky said, travel should be minimal
> when interpretting a line of code.  Fully qualified naming is a better
> style because you know immediately, from the code itself, where the
> identifier lives.  And if you need to see the declaration, you know
> immediately where to go.

How so? Why should I care about the declaration/definition places? What
should be a fully qualified name of a dispatching call to a 10-times
overridden primitive operation, provided that 5 of them were private? The
first, the last, one in the middle?

>> BTW, what about banning implicit "use" of "Standard"? Care to write
>> an AI to make Integer, "+", "-" etc invisible? (:-))
> 
> The "use type" clause is a different beast, and I do not object to its
> use; nor is it banned in any coding standard I've read.

What is the difference between "+" and "Add"?

>>> Then to possibly get multiple hits and have to compare two lists of
>>> packages to discover which hit is the correct one.  By the time you
>>> make it to the declaration you're looking for, you've forgotten why
>>> you need to look at it :)
>> 
>> It is no matter "where", "what" does matter. If you need to
>> frequently browse sources to determine "what", then the program is
>> poorly designed.
> 
> Certainly not.  I would say just the opposit.  If you're repeating
> information from your declaration in your identifiers, then you've
> created a maintenance problem by introducing too much noise, also
> forcing identifiers to change whenever the declaration changes.  A
> good design doesn't repeat this information.

It seems that you are arguing my point. Name prefix is that noise you are
talking about.

>>> Clearly the typing time saved by the use clause cannot possibly offset
>>> the time lost on all the resulting code searches.
>> 
>> What about the time spent on reading something like A.B.C.D.E.F.G.H?
> 
> If you have something like that, then there's something wrong with the
> architecture of your project.  A user should not need visibility into
> such a deep level within an external component.

That might be true, but irrelevant because the implementation of H should
know A and A.B and A.B.C etc. According to your theory within H anything
from G must be referred as A.B.C.D.E.F.G.X!

Now if you aren't going to argue against child packages, consider "use A"
as an ad-hoc parent specification.

BTW, one probably could even remove "use" from the language allowing
multiple parents instead.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de