Packages

package root

Definition Classes: root

package cats

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 arrow

Definition Classes: cats

package conversions

Definition Classes: cats

package data

Definition Classes: cats

package evidence

Definition Classes: cats

package free

Definition Classes: cats

package instances

Definition Classes: cats

package kernel

Definition Classes: cats

package laws

Definition Classes: cats

package syntax

Definition Classes: cats

package tests

Definition Classes: cats

Align

Alternative

Always

Applicative

ApplicativeError

ApplicativeThrow

Apply

ApplyArityFunctions

Bifoldable

Bifunctor

Bimonad

Bitraverse

CoflatMap

CommutativeApplicative

CommutativeApply

CommutativeFlatMap

CommutativeMonad

Comonad

Contravariant

ContravariantMonoidal

ContravariantSemigroupal

Defer

Distributive

Eval

EvalGroup

EvalMonoid

EvalSemigroup

FlatMap

FlatMapArityFunctions

Foldable

FoldableNFunctions

Functor

FunctorFilter

FunctorFilterInstances0

Inject

InjectK

Invariant

InvariantMonoidal

InvariantSemigroupal

Later

Monad

MonadError

MonadThrow

MonoidK

NonEmptyAlternative

NonEmptyParallel

NonEmptyReducible

NonEmptyTraverse

NotNull

Now

Parallel

ParallelArityFunctions

ParallelArityFunctions2

Reducible

Representable

SemigroupK

SemigroupKInstances0

Semigroupal

SemigroupalArityFunctions

Show

StackSafeMonad

Traverse

TraverseFilter

UnorderedFoldable

UnorderedTraverse

implicits

cats

Foldable

Companion trait Foldable

object Foldable extends Serializable

Source: Foldable.scala

Linear Supertypes

Serializable, Serializable, AnyRef, Any

Ordering

Alphabetic
By Inheritance

Inherited

Foldable
Serializable
Serializable
AnyRef
Any

Hide All
Show All

Visibility

Public
All

Type Members

trait AllOps[F[_], A] extends Ops[F, A] with UnorderedFoldable.AllOps[F, A]
trait Ops[F[_], A] extends Serializable
trait ToFoldableOps extends Serializable

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
def apply[F[_]](implicit instance: Foldable[F]): Foldable[F]
Summon an instance of Foldable for F.
Summon an instance of Foldable for F.

Annotations
@inline()
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( ... ) @native()
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def finalize(): Unit

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
Annotations
@native()
def hashCode(): Int

Definition Classes
AnyRef → Any
Annotations
@native()
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
def iterateRight[A, B](iterable: Iterable[A], lb: Eval[B])(f: (A, Eval[B]) ⇒ Eval[B]): Eval[B]
def iterateRightDefer[G[_], A, B](iterable: Iterable[A], lb: G[B])(f: (A, G[B]) ⇒ G[B])(implicit arg0: Defer[G]): G[B]
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( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... ) @native()

Deprecated Value Members

object nonInheritedOps extends ToFoldableOps

Annotations
@deprecated
Deprecated
(Since version 2.2.0) Use cats.syntax object imports
object ops

Annotations
@deprecated
Deprecated
(Since version 2.2.0) Use cats.syntax object imports

Packages

Foldable

Companion trait Foldable

object Foldable extends Serializable

Type Members

Value Members

Deprecated Value Members

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped

Packages

Foldable 

Companion trait Foldable

object Foldable extends Serializable

Type Members

Value Members

Deprecated Value Members

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped

Foldable