monix-bio/monix.bio.instances/CatsMonadToSemigroup

CatsMonadToSemigroup

class CatsMonadToSemigroup[F[_], A](F: Monad[F], A: Semigroup[A]) extends Semigroup[F[A]]

Given that A has a cats.Monoid implementation, this builds a Semigroup[F[A]] instance for any F[_] data type that implements cats.effect.Sync.

Used for IO.

NOTE: nothing in this implementation is specific to Monix or to cats-effect, but these instances are not provided by default by Cats for any monad, probably because they aren't useful for every monad.

trait Semigroup[F[A]]

trait Serializable

class Object

trait Matchable

class Any

class CatsMonadToMonoid[F, A]

Value members

Concrete methods

Definition Classes: Semigroup

Inherited methods

Given a sequence of as, combine them and return the total.

If the sequence is empty, returns None. Otherwise, returns Some(total).

Example:

scala> import cats.kernel.instances.string._

scala> Semigroup[String].combineAllOption(List("One ", "Two ", "Three"))
res0: Option[String] = Some(One Two Three)

scala> Semigroup[String].combineAllOption(List.empty)
res1: Option[String] = None

Inherited from: Semigroup

Return a combined with itself n times.

Example:

scala> import cats.kernel.instances.int._
scala> import cats.kernel.instances.string._

scala> Semigroup[Int].combineN(1, 10)
res0: Int = 10

scala> Semigroup[String].combineN("ha", 3)
res1: String = hahaha

Inherited from: Semigroup

Between each pair of elements insert middle This name matches the term used in Foldable and Reducible and a similar Haskell function.

Inherited from: Semigroup

return a semigroup that reverses the order so combine(a, b) == reverse.combine(b, a)

Inherited from: Semigroup