Hi Pascal,
Thanks for the input. I think we are going to be okay here since, as Koert
said, the current serializers use runtime type information. We could also
keep at ClassTag around for the original type when the RDD was created.
Good things to be aware of though.
Michael
On Sat, Mar 22, 2014 at 12:42 PM, Pascal Voitot Dev <
pascal.voitot....@gmail.com> wrote:
> On Sat, Mar 22, 2014 at 8:38 PM, David Hall <d...@cs.berkeley.edu> wrote:
>
> > On Sat, Mar 22, 2014 at 8:59 AM, Pascal Voitot Dev <
> > pascal.voitot....@gmail.com> wrote:
> >
> > > The problem I was talking about is when you try to use typeclass
> > converters
> > > and make them contravariant/covariant for input/output. Something like:
> > >
> > > Reader[-I, +O] { def read(i:I): O }
> > >
> > > Doing this, you soon have implicit collisions and philosophical
> concerns
> > > about what it means to serialize/deserialize a Parent class and a Child
> > > class...
> > >
> >
> >
> > You should (almost) never make a typeclass param contravariant. It's
> almost
> > certainly not what you want:
> >
> > https://issues.scala-lang.org/browse/SI-2509
> >
> > -- David
> >
>
> I confirm that it's a pain and I must say I never do it but I've inherited
> historical code that did it :)
>
