hackwaly

module type TERM = sig
  type t
  type tvar
  val var_opt : t -> tvar option
  val compare_var : tvar -> tvar -> int
  val same_functor : t -> t -> bool
  val args : t -> t list
end

module Make (Term : TERM) = struct

mandubian

Here is a fast explanation on this study for Freek to improve compile-time:

https://github.com/ProjectSeptemberInc/freek/blob/optim/cop/src/main/scala/CoproductK.scala#L14-L34

In Freek, Higher-Kinded Coproduct was based on Shapeless HList/Coproduct representation like:

sealed trait CoproductK[A] extends Product with Serializable

sealed trait CNilK[A] extends CoproductK[A]

milessabin

miles@frege:~$ ./shapeless.sh 
Loading...
Welcome to the Ammonite Repl 0.5.2
(Scala 2.11.7 Java 1.8.0_51)
@ val l = 23 :: "foo" :: true :: HNil
l: Int :: String :: Boolean :: HNil = ::(23, ::("foo", ::(true, HNil)))
@

propensive

// Define the following traits and companion object
// It's in Rapture Core (https://github.com/propensive/rapture-core) if you don't want to

trait LowPriorityDefaultsTo { implicit def fallback[T, S]: DefaultsTo[T, S] = null }
object DefaultsTo extends LowPriorityDefaultsTo { implicit def defaultDefaultsTo[T]: DefaultsTo[T, T] = null }
trait DefaultsTo[T, S]

// Then, assuming we want to specify a default for a type class like `Namer`,
case class Namer[T](name: String)

viktorklang

#!/bin/bash

#########################################################################################################################
# MIT License
#  
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.