core/spire.std/OptionCMonoid

OptionCMonoid

@SerialVersionUID(0L)
class OptionCMonoid[A] extends OptionMonoid[A] with CommutativeMonoid[Option[A]]
class OptionMonoid[A]
trait Monoid[Option[A]]
trait Semigroup[Option[A]]
class Object
trait Matchable
class Any

Value members

Inherited methods

def combine(x: Option[A], y: Option[A]): Option[A]
Inherited from:
OptionMonoid
def combineAll(as: IterableOnce[Option[A]]): Option[A]

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
override def combineAllOption(as: IterableOnce[Option[A]]): Option[Option[A]]
Definition Classes
Inherited from:
Monoid
override def combineN(a: Option[A], n: Int): Option[A]

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
def empty: Option[A]
Inherited from:
OptionMonoid
override def intercalate(middle: Option[A]): CommutativeSemigroup[Option[A]]
Definition Classes
Inherited from:
CommutativeSemigroup
def isEmpty(a: Option[A])(implicit ev: Eq[Option[A]]): Boolean

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