Re: c++ "with" keyword

[Gianni Mariani <gmariani at chaincast dot com>]

Robert Dewar wrote:

> > I think you missed the point.
> >
> > The fact that this can happen - even if you make it illegal, means more 
> > maintenance.  Using it from libraries also means that simply adding a 
> > member to a library could cause untold number of users to that library 
> > have compilation errors.
> >
> > Besides, this was a "real" problem with a Pascal program I wrote many 20 
> > years ago and why I never used the 'with' keyword since.
> >    
> A lot depends on whether you want to favor the reader or writer. Your
> complaint about having to fix existing programs when a change is made
> is about favoring the writer, but the concern about encouraging long
> name usage is about favoring the reader.
I favour code maintenance.  I don't like fixing bugs only to introduce a 
whole bunch of new ones that are hard to find.  This is probably my 
largest concern when it comes to writing code.

Perhaps this is why we have a large difference of opinion of what is 
more important.

> Note that this is an old discussion in the Ada world. Ada allows the USE
> clause to open up visibility, but at the expense of possible illegalities
> when new names are used. Some Ada users eschew USE completely, but others
> find USE an important capability for improving readability of code.
>
> So I find this general argument against WITH dubious. For sure it is not
> a consensus viewpoint, since in practice the world divides between those
> who dislike all implicit naming and those who find it valuable. Note that
> if such a feature is used, you presumably would prefer not to use it, but
> I don't regard that as a good argument for imposing your viewpoint.
>
> The stronger argument against adding WITH in C++ seems to be that there
> is already an adequate mechanism for providing short nicknames locally
> for long names, and WITH does not provide sufficient extra functionality
> to be worth the effort (note that compiler writers will worry that taking
> the address of something may degrade the code, so the example with the
> reference is an interesting one for the optimization crowd :-)
>  
Agreed.