Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/ethul/typeclass-inject
Inject has been incorporated into Scalaz
https://github.com/ethul/typeclass-inject
Last synced: about 2 months ago
JSON representation
Inject has been incorporated into Scalaz
- Host: GitHub
- URL: https://github.com/ethul/typeclass-inject
- Owner: ethul
- License: mit
- Created: 2013-08-10T15:23:21.000Z (over 11 years ago)
- Default Branch: master
- Last Pushed: 2013-08-31T14:36:26.000Z (over 11 years ago)
- Last Synced: 2024-04-08T20:47:53.104Z (9 months ago)
- Language: Scala
- Homepage: https://github.com/scalaz/scalaz/pull/502
- Size: 125 KB
- Stars: 6
- Watchers: 4
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Inject
A scala implementation of the `Inject` typeclass from [Data types a la carte](http://www.staff.science.uu.nl/~swier004/Publications/DataTypesALaCarte.pdf) (Swierstra 2008).
# Example
```scala
import scalaz.{Coproduct, Free, Functor}, Free.Return
import typeclass.Inject, Inject._
sealed trait Test1Algebra[A]
case class Test1[A](keys: Seq[String], h: Int => A) extends Test1Algebra[A]
sealed trait Test1AlgebraInstances {
implicit def test1AlgebraAFunctor: Functor[Test1Algebra] =
new Functor[Test1Algebra] {
def map[A, B](a: Test1Algebra[A])(f: A => B): Test1Algebra[B] = a match {
case Test1(k, h) => Test1(k, x => f(h(x)))
}
}
}
sealed trait Test1AlgebraFunctions {
def test1[F[_] : Functor](keys: Seq[String])(implicit I: Inject[Test1Algebra, F]): Free[F, Int] =
inject[F, Test1Algebra, Int](Test1(keys, Return(_)))
}
object Test1Algebra extends Test1AlgebraInstances with Test1AlgebraFunctions
sealed trait Test2Algebra[A]
case class Test2[A](keys: Seq[String], h: Int => A) extends Test2Algebra[A]
sealed trait Test2AlgebraInstances {
implicit def test2AlgebraAFunctor: Functor[Test2Algebra] =
new Functor[Test2Algebra] {
def map[A, B](a: Test2Algebra[A])(f: A => B): Test2Algebra[B] = a match {
case Test2(k, h) => Test2(k, x => f(h(x)))
}
}
}
sealed trait Test2AlgebraFunctions {
def test2[F[_] : Functor](keys: Seq[String])(implicit I: Inject[Test2Algebra, F]): Free[F, Int] =
inject[F, Test2Algebra, Int](Test2(keys, Return(_)))
}
object Test2Algebra extends Test2AlgebraInstances with Test2AlgebraFunctions
sealed trait Test3Algebra[A]
case class Test3[A](keys: Seq[String], h: Int => A) extends Test3Algebra[A]
sealed trait Test3AlgebraInstances {
implicit def test3AlgebraAFunctor: Functor[Test3Algebra] =
new Functor[Test3Algebra] {
def map[A, B](a: Test3Algebra[A])(f: A => B): Test3Algebra[B] = a match {
case Test3(k, h) => Test3(k, x => f(h(x)))
}
}
}
sealed trait Test3AlgebraFunctions {
def test3[F[_] : Functor](keys: Seq[String])(implicit I: Inject[Test3Algebra, F]): Free[F, Int] =
inject[F, Test3Algebra, Int](Test3(keys, Return(_)))
}
object Test3Algebra extends Test3AlgebraInstances with Test3AlgebraFunctions
object Test {
import Test1Algebra._, Test2Algebra._, Test3Algebra._
type C0[A] = Coproduct[Test1Algebra, Test2Algebra, A]
type C1[A] = Coproduct[Test3Algebra, C0, A]
type T[A] = C1[A]
val res =
for {
a <- test1[T]("aa" :: Nil)
b <- test2[T]("bb" :: Nil)
c <- test3[T]("cc" :: Nil)
} yield (a, b, c)
}
```