Type Class Resolution Example

main.scala

package com.main

import com.model.Model
import com.typeclass._
	
object Main extends App {
	import com.alternate._
	
	val bar = Model(1, 2)
	println("The result is: " + foo(bar))
}

model.scala

package com.model

import com.typeclass.CanFoo

case class Model(one: Int, two: Int)

object Model {
	implicit val modelFoo = new CanFoo[Model] {
		def foo(m: Model) = m.one
	}
}

package.scala

package com

import com.model.Model

package object typeclass {
	def foo[A: CanFoo](a: A): Int = implicitly[CanFoo[A]].foo(a)
}

package object alternate {
	import com.typeclass.CanFoo
	
	implicit val modelFoo = new CanFoo[Model] {
		def foo(m: Model) = m.two
	}
}

typeclass.scala

package com.typeclass

trait CanFoo[A] {
	def foo(x: A): Int
}