/core/src/main/scala/scalaz/Name.scala
http://github.com/scalaz/scalaz · Scala · 131 lines · 118 code · 10 blank · 3 comment · 0 complexity · 2d37ded2bcb6a91f067c274e9b6bdb09 MD5 · raw file
- package scalaz
- import scala.annotation.tailrec
- /** Call by name */
- sealed abstract class Name[A] {
- def value: A
- }
- /** Call by need */
- final class Need[A] private(private[this] var eval: () => A) extends Name[A] {
- lazy val value: A = {
- val value0 = eval()
- eval = null
- value0
- }
- }
- /** Call by value */
- final case class Value[A](value: A) extends Name[A]
- object Name {
- def apply[A](a: => A) = new Name[A] {
- def value = a
- }
- def unapply[A](v: Name[A]): Option[A] = Some(v.value)
- implicit val name: Monad[Name] with BindRec[Name] with Comonad[Name] with Distributive[Name] with Traverse1[Name] with Zip[Name] with Unzip[Name] with Align[Name] with Cozip[Name] =
- new Monad[Name] with BindRec[Name] with Comonad[Name] with Distributive[Name] with Traverse1[Name] with Zip[Name] with Unzip[Name] with Align[Name] with Cozip[Name] {
- override def foldMap1[A, B: Semigroup](fa: Name[A])(f: A => B) = f(fa.value)
- override def foldLeft[A, B](fa: Name[A], z: B)(f: (B, A) => B) = f(z, fa.value)
- override def foldRight[A, B](fa: Name[A], z: => B)(f: (A, => B) => B) = f(fa.value, z)
- def alignWith[A, B, C](f: A \&/ B => C) = (a, b) => Name(f(\&/.Both(a.value, b.value)))
- def cozip[A, B](x: Name[A \/ B]) = x.value.bimap(Name(_), Name(_))
- def foldMapRight1[A, B](fa: Name[A])(z: A => B)(f: (A, => B) => B) = z(fa.value)
- def traverse1Impl[G[_], A, B](fa: Name[A])(f: A => G[B])(implicit G: Apply[G]) = G.map(f(fa.value))(Name(_))
- def unzip[A, B](a: Name[(A, B)]) = (Name(a.value._1), Name(a.value._2))
- def zip[A, B](a: => Name[A], b: => Name[B]) = Name((a.value, b.value))
- def point[A](a: => A) = Name(a)
- override def map[A, B](fa: Name[A])(f: A => B) = Name(f(fa.value))
- override def ap[A, B](fa: => Name[A])(f: => Name[A => B]) =
- Name(f.value apply fa.value)
- def bind[A,B](v: Name[A])(f: A => Name[B]): Name[B] = Name(f(v.value).value)
- def cobind[A, B](fa: Name[A])(f: Name[A] => B): Name[B] = Name(f(fa))
- override def cojoin[A](a: Name[A]): Name[Name[A]] = Name(a)
- def copoint[A](p: Name[A]): A = p.value
- def distributeImpl[G[_], A, B](fa: G[A])(f: A => Name[B])(implicit G: Functor[G]) =
- Name(G.map(fa)(a => f(a).value))
- @tailrec
- def tailrecM[A, B](a: A)(f: A => Name[A \/ B]): Name[B] =
- f(a).value match {
- case -\/(a0) => tailrecM(a0)(f)
- case \/-(b) => Name(b)
- }
- }
- implicit def nameEqual[A: Equal]: Equal[Name[A]] = new Equal[Name[A]] {
- def equal(a1: Name[A], a2: Name[A]): Boolean = Equal[A].equal(a1.value, a2.value)
- }
- implicit def covariant: IsCovariant[Name] = IsCovariant.force
- }
- object Need {
- def apply[A](a: => A): Need[A] = new Need(() => a)
- def unapply[A](x: Need[A]): Option[A] = Some(x.value)
- implicit val need: Monad[Need] with BindRec[Need] with Comonad[Need] with Distributive[Need] with Traverse1[Need] with Zip[Need] with Unzip[Need] with Align[Need] with Cozip[Need] =
- new Monad[Need] with BindRec[Need] with Comonad[Need] with Distributive[Need] with Traverse1[Need] with Zip[Need] with Unzip[Need] with Align[Need] with Cozip[Need] {
- override def foldMap1[A, B: Semigroup](fa: Need[A])(f: A => B) = f(fa.value)
- override def foldLeft[A, B](fa: Need[A], z: B)(f: (B, A) => B) = f(z, fa.value)
- override def foldRight[A, B](fa: Need[A], z: => B)(f: (A, => B) => B) = f(fa.value, z)
- def alignWith[A, B, C](f: A \&/ B => C) = (a, b) => Need(f(\&/.Both(a.value, b.value)))
- def cozip[A, B](x: Need[A \/ B]) = x.value.bimap(Need(_), Need(_))
- def foldMapRight1[A, B](fa: Need[A])(z: A => B)(f: (A, => B) => B) = z(fa.value)
- def traverse1Impl[G[_], A, B](fa: Need[A])(f: A => G[B])(implicit G: Apply[G]) = G.map(f(fa.value))(Need(_))
- def unzip[A, B](a: Need[(A, B)]) = (Need(a.value._1), Need(a.value._2))
- def zip[A, B](a: => Need[A], b: => Need[B]) = Need((a.value, b.value))
- def point[A](a: => A) = Need(a)
- override def map[A, B](fa: Need[A])(f: A => B) = Need(f(fa.value))
- override def ap[A, B](fa: => Need[A])(f: => Need[A => B]) =
- Need(f.value apply fa.value)
- def bind[A, B](v: Need[A])(f: A => Need[B]): Need[B] = Need(f(v.value).value)
- def cobind[A, B](fa: Need[A])(f: Need[A] => B): Need[B] = Need(f(fa))
- override def cojoin[A](a: Need[A]): Need[Need[A]] = Need(a)
- def copoint[A](p: Need[A]): A = p.value
- def distributeImpl[G[_], A, B](fa: G[A])(f: A => Need[B])(implicit G: Functor[G]) =
- Need(G.map(fa)(a => f(a).value))
- @tailrec
- def tailrecM[A, B](a: A)(f: A => Need[A \/ B]): Need[B] =
- f(a).value match {
- case -\/(a0) => tailrecM(a0)(f)
- case \/-(b) => Need(b)
- }
- }
- implicit def needEqual[A: Equal]: Equal[Need[A]] = new Equal[Need[A]] {
- def equal(a1: Need[A], a2: Need[A]): Boolean = Equal[A].equal(a1.value, a2.value)
- }
- implicit def covariant: IsCovariant[Value] = IsCovariant.force
- }
- object Value {
- implicit val value: Monad[Value] with BindRec[Value] with Comonad[Value] with Distributive[Value] with Traverse1[Value] with Zip[Value] with Unzip[Value] with Align[Value] with Cozip[Value] =
- new Monad[Value] with BindRec[Value] with Comonad[Value] with Distributive[Value] with Traverse1[Value] with Zip[Value] with Unzip[Value] with Align[Value] with Cozip[Value] {
- override def foldMap1[A, B: Semigroup](fa: Value[A])(f: A => B) = f(fa.value)
- override def foldLeft[A, B](fa: Value[A], z: B)(f: (B, A) => B) = f(z, fa.value)
- override def foldRight[A, B](fa: Value[A], z: => B)(f: (A, => B) => B) = f(fa.value, z)
- def alignWith[A, B, C](f: A \&/ B => C) = (a, b) => Value(f(\&/.Both(a.value, b.value)))
- def cozip[A, B](x: Value[A \/ B]) = x.value.bimap(Value(_), Value(_))
- def foldMapRight1[A, B](fa: Value[A])(z: A => B)(f: (A, => B) => B) = z(fa.value)
- def traverse1Impl[G[_], A, B](fa: Value[A])(f: A => G[B])(implicit G: Apply[G]) = G.map(f(fa.value))(Value(_))
- def unzip[A, B](a: Value[(A, B)]) = (Value(a.value._1), Value(a.value._2))
- def zip[A, B](a: => Value[A], b: => Value[B]) = Value((a.value, b.value))
- def point[A](a: => A) = Value(a)
- def bind[A, B](v: Value[A])(f: A => Value[B]): Value[B] = f(v.value)
- def cobind[A, B](fa: Value[A])(f: Value[A] => B): Value[B] = Value(f(fa))
- override def cojoin[A](a: Value[A]): Value[Value[A]] = Value(a)
- def copoint[A](p: Value[A]): A = p.value
- def distributeImpl[G[_], A, B](fa: G[A])(f: A => Value[B])(implicit G: Functor[G]) =
- Value(G.map(fa)(a => f(a).value))
- @tailrec
- def tailrecM[A, B](a: A)(f: A => Value[A \/ B]): Value[B] =
- f(a).value match {
- case -\/(a0) => tailrecM(a0)(f)
- case \/-(b) => Value(b)
- }
- }
- implicit def valueEqual[A: Equal]: Equal[Value[A]] = new Equal[Value[A]] {
- def equal(a1: Value[A], a2: Value[A]): Boolean = Equal[A].equal(a1.value, a2.value)
- }
- implicit def covariant: IsCovariant[Value] = IsCovariant.force
- }