Tom Switzer

@non See https://github.com/non/spire/pull/438 - we can get unboxed (value class) + optionally checked at compile time for constants. Specifically: https://github.com/kevinmeredith/spire/blob/jetdim_compile_time_check/macros/src/main/scala/spire/macros/PositiveInt.scala (It's a case class there, but a value class may...

So, @denisrosset is currently looking into adding an [linearly ordered group](https://en.wikipedia.org/wiki/Linearly_ordered_group), either to algebra or spire. May be worth touching base with him. This actually is sort of ground work...

I'm actually not against having a default of addition for Semigroup and friends. I am a little uneasy about adding the defaults into the companion object. We started with this...

One alternative is to simply duplicate all the implicit instances for all parent type classes, so we don't have to have the implicit-child search I described above. The only issue...

@mosesn It is not open source (currently just a prototype in a gist somewhere). I'll take a stab at cleaning it up and "releasing" it this weekend though!

Something to think about while doing this, is adding a `case class Forest(trees: Map[Int, Tree[K, V, T])` in `brushfire-training` while we're at it. A lot of helper methods could be...

I really like the idea overall. Hard to tell if it is too overfit, but I agree that we need to start somewhere! I'm sort of giving some nit-picky comments...

You can run the example with something like: `SPARK_HOME=/path/to/spark ./iris-spark`

We do have some property based tests now! But not enough that I'd really consider this issue done yet.

@avibryant So, this has some of the stuff I've been doing (still very WIP), but the important bits are: - `FValue` ADT, which is basically just `Number | Text |...