Re: [gentoo-dev] DESCRIPTION in eclasses

[Mike Frysinger]

On Thursday 19 July 2012 02:57:09 Ulrich Mueller wrote:
> >>>>> On Wed, 18 Jul 2012, Ciaran McCreesh wrote:
> >> Many eclasses (eutils being the most prominent example) contain:
> >> DESCRIPTION="Based on the ${ECLASS} eclass"
> >>
> >> Is this of any use?
> >
> > The reason that sort of thing is there is because in the olden days
> > before we had specs or EAPIs or anything like that, eclasses were
> > originally designed and implemented as "classes" in an OO type manner.
> > The idea was that there would be a "base" eclass, and then you'd derive
> > "kde", "gnome" etc eclasses from there, all in a nice hierarchy, and
> > you'd be expected to "override" variables like DESCRIPTION as you go
> > down the tree.
> >
> > As it turns out, eclasses ended up being used in a completely different
> > way. But you still see bits of the original idea cropping up, such as
> > in the words "class" and "inherit" and "base".
>
> Thanks, this explains why these DESCRIPTIONs are there.
>
> But history left aside, are they still useful today? If not, then they
> should be removed.

it depends.  for some of the eclasses which are just eblits, it makes sense 
(e.g. toolchain/mariadb/etc...).  for some plugin based ones, it also makes 
sense because the packages are fairly mechanical in nature (e.g. stardict/ 
linux-kernel/etc...).  for core ones (like eutils), i liked it in the past 
because it provided a quick way to detect when someone had their inherit order 
wrong (although this isn't nearly as common a problem anymore).

so some trimming could probably be done, and we should probably discourage new 
eclasses from just copying & pasting, but removing it from all eclasses 
doesn't make much sense.
-mike