CatsMonadToMonoid
Given that A
has a cats.Semigroup
implementation, this
builds a Semigroup[F[A]]
instance for any F[_]
data type
that implements cats.Monad
.
Used for both Task and monix.eval.Coeval.
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.
Value members
Inherited methods
Given a sequence of as
, sum them using the monoid and return the total.
Given a sequence of as
, sum them using the monoid and return the total.
Example:
scala> import cats.kernel.instances.string._
scala> Monoid[String].combineAll(List("One ", "Two ", "Three"))
res0: String = One Two Three
scala> Monoid[String].combineAll(List.empty)
res1: String = ""
- Inherited from:
- Monoid
Return a
appended to itself n
times.
Return a
appended to itself n
times.
Example:
scala> import cats.kernel.instances.string._
scala> Monoid[String].combineN("ha", 3)
res0: String = hahaha
scala> Monoid[String].combineN("ha", 0)
res1: String = ""
- Definition Classes
- Inherited from:
- =0")elseif(n.==(0))Monoid.this.emptyelseMonoid.this.repeatedCombineN(a,n)">Monoid
Between each pair of elements insert middle This name matches the term used in Foldable and Reducible and a similar Haskell function.
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
Tests if a
is the identity.
Tests if a
is the identity.
Example:
scala> import cats.kernel.instances.string._
scala> Monoid[String].isEmpty("")
res0: Boolean = true
scala> Monoid[String].isEmpty("something")
res1: Boolean = false
- Inherited from:
- Monoid