Packages

trait Group[A] extends Monoid[A]

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  1. Group
  2. Monoid
  3. Semigroup
  4. Serializable
  5. Serializable
  6. Any
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Abstract Value Members

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

    Associative operation which combines two values.

    Associative operation which combines two values.

    Example:

    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)
    Definition Classes
    Semigroup
  2. abstract def empty: A

    Return the identity element for this monoid.

    Return the identity element for this monoid.

    Example:

    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
    Definition Classes
    Monoid
  3. abstract def getClass(): Class[_]
    Definition Classes
    Any
  4. abstract def inverse(a: A): A

    Find the inverse of a.

    Find the inverse of a.

    combine(a, inverse(a)) = combine(inverse(a), a) = empty.

    Example:

    scala> import cats.kernel.instances.int._
    
    scala> Group[Int].inverse(5)
    res0: Int = -5

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    Any
  2. final def ##(): Int
    Definition Classes
    Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def combineAll(as: IterableOnce[A]): 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 = ""
    Definition Classes
    Monoid
  6. def combineAllOption(as: IterableOnce[A]): Option[A]

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

    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
    Definition Classes
    MonoidSemigroup
  7. def combineN(a: A, n: Int): A

    Return a appended to itself n times.

    Return a appended to itself n times. If n is negative, then this returns inverse(a) appended to itself n times.

    Definition Classes
    GroupMonoidSemigroup
  8. def equals(arg0: Any): Boolean
    Definition Classes
    Any
  9. def hashCode(): Int
    Definition Classes
    Any
  10. def intercalate(middle: A): Semigroup[A]

    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.

    Definition Classes
    Semigroup
  11. def isEmpty(a: A)(implicit ev: Eq[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
    Definition Classes
    Monoid
  12. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  13. def remove(a: A, b: A): A

    Remove the element b from a.

    Remove the element b from a.

    Equivalent to combine(a, inverse(b))

    Example:

    scala> import cats.kernel.instances.int._
    
    scala> Group[Int].remove(5, 2)
    res0: Int = 3
  14. def repeatedCombineN(a: A, n: Int): A

    Return a combined with itself more than once.

    Return a combined with itself more than once.

    Attributes
    protected[this]
    Definition Classes
    Semigroup
  15. def reverse: Monoid[A]

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

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

    Definition Classes
    MonoidSemigroup
  16. def toString(): String
    Definition Classes
    Any

Inherited from Monoid[A]

Inherited from Semigroup[A]

Inherited from Serializable

Inherited from Serializable

Inherited from Any

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