Packages

Definition Classes: root

The cats root package contains all the trait signatures of most Scala type classes.

Cats type classes are implemented using the approach from the Type classes as objects and implicits article.

For each type class, cats provides three pieces: - Its signature: a trait that is polymorphic on a type parameter. Type class traits inherit from other type classes to indicate that any implementation of the lower type class (e.g. Applicative) can also serve as an instance for the higuer type class (e.g. Functor). - Type class 'instances, which are classes and objects that implement one or more type class signatures for some specific types. Type class instances for several data types from the Java or Scala standard libraries are declared in the subpackage cats.instances. - Syntax extensions, each of which provides the methods of the type class defines as extension methods (which in Scala 2 are encoded as implicit classes) for values of any type F; given that an instance of the type class for the receiver type (this) is in the implicit scope. Symtax extensions are declared in the cats.syntax package. - A set of laws, that are also generic on the type of the class, and are only defined on the operations of the type class. The purpose of these laws is to declare some algebraic relations (equations) between Scala expressions involving the operations of the type class, and test (but not verify) that implemented instances satisfy those equations. Laws are defined in the cats-laws package.

Although most of cats type classes are declared in this package, some are declared in other packages: - type classes that operate on base types (kind *), and their implementations for standard library types, are contained in cats.kernel, which is a different SBT project. However, they are re-exported from this package. - type classes of kind F[_, _], such as cats.arrow.Profunctor" or cats.arrow.Arrow, which are relevant for Functional Reactive Programming or optics, are declared in the cats.arrow package. - Also, those type classes that abstract over (pure or impure) functional runtime effects are declared in the cats-effect library. - Some type classes for which no laws can be provided are left out of the main road, in a small and dirty alley. These are the alleycats.

Definition Classes: root

package kernel

Definition Classes: cats

package instances

Definition Classes: kernel

package laws

Definition Classes: kernel

HashToHashingConversion

LowerBounded

LowerBoundedEnumerable

LowerBoundedFunctions

OrderToOrderingConversion

PartialNext

PartialNextLowerBounded

PartialOrder

PartialOrderFunctions

PartialOrderToPartialOrderingConversion

PartialPrevious

PartialPreviousUpperBounded

UpperBoundedEnumerable

UpperBoundedFunctions

cats.kernel

MonoidFunctions

abstract class MonoidFunctions[M[T] <: Monoid[T]] extends SemigroupFunctions[M]

Annotations: @suppressUnusedImportWarningForScalaVersionSpecific()
Source: Monoid.scala

Linear Supertypes

SemigroupFunctions[M], AnyRef, Any

Known Subclasses

CommutativeGroup, CommutativeMonoid, Group, GroupFunctions, Monoid

Type Hierarchy

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Inherited

MonoidFunctions
SemigroupFunctions
AnyRef
Any

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Visibility

Public
Protected

Instance Constructors

new MonoidFunctions()

Value Members

final def !=(arg0: Any): Boolean
Definition Classes
AnyRef → Any
final def ##: Int
Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean
Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0
Definition Classes
Any
def clone(): AnyRef
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.CloneNotSupportedException]) @native()
def combine[A](x: A, y: A)(implicit ev: M[A]): A
Definition Classes
SemigroupFunctions
def combineAll[A](as: IterableOnce[A])(implicit ev: M[A]): A
def combineAllOption[A](as: IterableOnce[A])(implicit ev: M[A]): Option[A]
Definition Classes
SemigroupFunctions
def combineN[A](a: A, n: Int)(implicit ev: M[A]): A
Definition Classes
SemigroupFunctions
def empty[A](implicit ev: M[A]): A
final def eq(arg0: AnyRef): Boolean
Definition Classes
AnyRef
def equals(arg0: AnyRef): Boolean
Definition Classes
AnyRef → Any
def finalize(): Unit
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.Throwable])
final def getClass(): Class[_ <: AnyRef]
Definition Classes
AnyRef → Any
Annotations
@native()
def hashCode(): Int
Definition Classes
AnyRef → Any
Annotations
@native()
def isCommutative[A](implicit ev: M[A]): Boolean
Definition Classes
SemigroupFunctions
def isEmpty[A](a: A)(implicit m: M[A], ev: Eq[A]): Boolean
def isIdempotent[A](implicit ev: M[A]): Boolean
Definition Classes
SemigroupFunctions
final def isInstanceOf[T0]: Boolean
Definition Classes
Any
def maybeCombine[A](x: A, oy: Option[A])(implicit ev: M[A]): A
Definition Classes
SemigroupFunctions
def maybeCombine[A](ox: Option[A], y: A)(implicit ev: M[A]): A
Definition Classes
SemigroupFunctions
final def ne(arg0: AnyRef): Boolean
Definition Classes
AnyRef
final def notify(): Unit
Definition Classes
AnyRef
Annotations
@native()
final def notifyAll(): Unit
Definition Classes
AnyRef
Annotations
@native()
final def synchronized[T0](arg0: => T0): T0
Definition Classes
AnyRef
def toString(): String
Definition Classes
AnyRef → Any
final def wait(): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long, arg1: Int): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException]) @native()

Packages

MonoidFunctions

abstract class MonoidFunctions[M[T] <: Monoid[T]] extends SemigroupFunctions[M]

Instance Constructors

Value Members

Inherited from SemigroupFunctions[M]

Inherited from AnyRef

Inherited from Any

Ungrouped

Packages

MonoidFunctions

abstract class MonoidFunctions[M[T] <: Monoid[T]] extends SemigroupFunctions[M]

Instance Constructors

Value Members

Inherited from SemigroupFunctions[M]

Inherited from AnyRef

Inherited from Any

Ungrouped

MonoidFunctions