Packages

c

cats.kernel.instances

OptionMonoid

class OptionMonoid[A] extends Monoid[Option[A]]

Source
OptionInstances.scala
Linear Supertypes
Monoid[Option[A]], Semigroup[Option[A]], Serializable, Serializable, AnyRef, Any
Type Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. OptionMonoid
  2. Monoid
  3. Semigroup
  4. Serializable
  5. Serializable
  6. AnyRef
  7. Any
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Visibility
  1. Public
  2. All

Instance Constructors

  1. new OptionMonoid()(implicit A: Semigroup[A])

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native() @IntrinsicCandidate()
  6. def combine(x: Option[A], y: Option[A]): Option[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
    OptionMonoid → Semigroup
  7. 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 = ""
    Definition Classes
    Monoid
  8. def combineAllOption(as: IterableOnce[Option[A]]): Option[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
    Monoid → Semigroup
  9. 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
    Monoid → Semigroup
  10. def empty: Option[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
    OptionMonoid → Monoid
  11. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  12. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  13. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @IntrinsicCandidate()
  14. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @IntrinsicCandidate()
  15. def intercalate(middle: Option[A]): Semigroup[Option[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
  16. 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
    Definition Classes
    Monoid
  17. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  18. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  19. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @IntrinsicCandidate()
  20. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @IntrinsicCandidate()
  21. def repeatedCombineN(a: Option[A], n: Int): Option[A]

    Return a combined with itself more than once.

    Return a combined with itself more than once.

    Attributes
    protected[this]
    Definition Classes
    Semigroup
  22. def reverse: Monoid[Option[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
    Monoid → Semigroup
  23. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  24. def toString(): String
    Definition Classes
    AnyRef → Any
  25. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  26. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  27. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] ) @Deprecated
    Deprecated

Inherited from Monoid[Option[A]]

Inherited from Semigroup[Option[A]]

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

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