Group

abstract def combine(x: A, y: A): A

Associative operation which combines two values.

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

scala> Semigroup[String].combine("Hello ", "World!")
res0: String = Hello World!

scala> Semigroup[Option[Int]].combine(None, Some(1))
res1: Option[Int] = Some(1)

abstract def empty: A

Return the identity element for this monoid.

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

scala> Monoid[String].empty
res0: String = ""

scala> Monoid[Int].empty
res1: Int = 0

abstract def getClass(): Class[_]

abstract def inverse(a: A): A

Find the inverse of a.

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

scala> Group[Int].inverse(5)
res0: Int = -5

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def combineAll(as: TraversableOnce[A]): A

Given a sequence of as, sum them using the monoid and return the total.

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 = ""

def combineAllOption(as: TraversableOnce[A]): Option[A]

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

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

def combineN(a: A, n: Int): A

Return a appended to itself n times.

def equals(arg0: Any): Boolean

def hashCode(): Int

def isEmpty(a: A)(implicit ev: Eq[A]): Boolean

Tests if a is the identity.

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

scala> Monoid[String].isEmpty("")
res0: Boolean = true

scala> Monoid[String].isEmpty("something")
res1: Boolean = false

final def isInstanceOf[T0]: Boolean

def remove(a: A, b: A): A

Remove the element b from a.

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

scala> Group[Int].remove(5, 2)
res0: Int = 3

def repeatedCombineN(a: A, n: Int): A

Return a combined with itself more than once.

def toString(): String