Add documentation around TypeClass derivation

[jedesah]

The documentation around typeclass derivation points to a blog post where the derivation process is explained in a very clear manner. The problem is that this blog post mentions that there will be a part 2 that deals with the notion of co-product and how it relates to typeclass derivation. As far as my understanding goes, this blog post never made it out and there is no ressource to find more about the emptycoproduct and coproduct methods that need to need to be implemented in order to derive TypeClassCompanion

[milessabin]

Fair comment. Are you able to make any headway with the TypeClass demos in the examples subproject? Or the examples in the tests?

[jedesah]

I have tried but still have a little bit of trouble understanding the purpose of those two methods. I have got them to somewhat work (mostly by being a copy cat) but would prefer a deep understanding of what is going on.

[milessabin]

OK, this might be better handled by a question on Stack Overflow.

[jedesah]

To be honest, I sort of feel like it should be added to the docs. Maybe not
the overview page, but some page that explains the type class derivation
process more in detail, but if you prefer I can go ahed and ask the
question on SO.

Once I understand what is going on, maybe I can write that page if it
stands a chance of being merged.

On Tue, Aug 26, 2014 at 12:27 AM, Miles Sabin notifications@github.com
wrote:

OK, this might be better handled by a question on Stack Overflow.

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[milessabin]

I was suggesting posting on SO to get a worked out answer. That might form the basis of an addition to the scaladoc or wiki. All contributions stand a very good chance of being merged :-)

[jedesah]

Oh! We are in agreement then! :-)

Here is the SO question (hopefully I expressed it correctly):
http://stackoverflow.com/questions/25517069/what-is-the-purpose-of-the-emptycoproduct-and-coproduct-methods-of-the-typeclass

[joroKr21]

More detailed info: https://underscore.io/books/shapeless-guide/