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package magnolia.examples
import magnolia._
import language.experimental.macros
import collection.immutable.ListMap
object `package` {
implicit class Equable[T: Eq](t: T) {
def isEqualTo(other: T): Boolean = implicitly[Eq[T]].isEqual(t, other)
}
implicit val eqString: Eq[String] = _ == _
implicit val eqBool: Eq[Boolean] = _ == _
implicit def eqList[T: Eq]: Eq[List[T]] =
(l1, l2) => l1.size == l2.size && (l1 zip l2).forall { case (e1, e2) => e1 isEqualTo e2 }
implicit def eqSet[T: Eq]: Eq[Set[T]] =
(s1, s2) => s1.size == s2.size && (s1 zip s2).forall { case (e1, e2) => e1 isEqualTo e2 }
}
sealed trait Tree
case class Branch(left: Tree, right: Tree) extends Tree
case class Leaf(value: Int) extends Tree
sealed trait Entity
case class Person(name: String, address: Address) extends Entity
case class Organization(name: String, contacts: Set[Person]) extends Entity
case class Address(lines: List[String], country: Country)
case class Country(name: String, code: String, salesTax: Boolean)
trait Eq[T] { def isEqual(a: T, b: T): Boolean }
object Eq {
implicit val eqInt: Eq[Int] = _ == _
implicit val derivation: ContravariantDerivation2[Eq] = new ContravariantDerivation2[Eq] {
type Return = Boolean
def call[T](eq: Eq[T], value1: T, value2: T): Boolean =
if(value1.getClass == value2.getClass) eq.isEqual(value1, value2) else false
def construct[T](body: (T, T) => Boolean): Eq[T] = body(_, _)
def join(elements: ListMap[String, Boolean]): Boolean = elements.forall(_._2)
}
implicit def generic[T]: Eq[T] = macro Macros.magnolia[T, Eq[_]]
}
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