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Packages

package root

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

Definition Classes
cats
AlignSyntax
AllSyntax
AllSyntaxBinCompat
AllSyntaxBinCompat0
AllSyntaxBinCompat1
AllSyntaxBinCompat2
AllSyntaxBinCompat3
AllSyntaxBinCompat4
AllSyntaxBinCompat5
AllSyntaxBinCompat6
AllSyntaxBinCompat7
AlternativeSyntax
ApplicativeErrorIdOps
ApplicativeErrorOps
ApplicativeErrorSyntax
ApplicativeIdOps
ApplicativeOps
ApplicativeSyntax
ApplyOps
ApplySyntax
ArrowChoiceSyntax
ArrowSyntax
BifoldableSyntax
BifunctorSyntax
BinestedIdOps
BinestedSyntax
BitraverseOps
BitraverseSyntax
ChoiceSyntax
CoflatMapSyntax
ComonadSyntax
ComposeSyntax
ContravariantMonoidalOps
ContravariantMonoidalSyntax
ContravariantSemigroupalSyntax
ContravariantSyntax
DistributiveOps
DistributiveSyntax
EitherIdOps
EitherKOps
EitherKSyntax
EitherObjectOps
EitherOps
EitherSyntax
EqOps
EqSyntax
FlatMapIdOps
FlatMapOps
FlatMapOptionOps
FlatMapOptionSyntax
FlatMapSyntax
FlattenOps
FoldableOps
FoldableOps0
FoldableSyntax
Function1Syntax
FunctorFilterSyntax
FunctorSyntax
FunctorTuple2Ops
GroupOps
GroupSyntax
GuardOps
HashOps
HashSyntax
IfApplyOps
IfMOps
IndexOps
InvariantSyntax
IorIdOps
IorSyntax
LeftNestedBitraverseOps
LeftOps
ListOps
ListSyntax
MonadErrorOps
MonadErrorRethrowOps
MonadErrorSyntax
MonadIdOps
MonadOps
MonadSyntax
MonoidOps
MonoidSyntax
NestedBitraverseOps
NestedFoldableOps
NestedIdOps
NestedReducibleOps
NestedSyntax
NonEmptyTraverseSyntax
OptionIdOps
OptionOps
OptionSyntax
OrderOps
OrderSyntax
ParallelApOps
ParallelApplyOps
ParallelApplySyntax
ParallelBisequenceOps
ParallelBitraverseOps
ParallelBitraverseSyntax
ParallelFlatSequenceOps
ParallelFlatSequenceOps1
ParallelFlatSyntax
ParallelFlatTraversableOps
ParallelFlatTraversableOps1
ParallelFoldMapAOps
ParallelFoldMapASyntax
ParallelLeftSequenceOps
ParallelLeftTraverseOps
ParallelSequenceFilterOps
ParallelSequenceOps
ParallelSequenceOps1
ParallelSequence_Ops
ParallelSyntax
ParallelTraversableOps
ParallelTraversableOps1
ParallelTraversable_Ops
ParallelTraverseFilterOps
ParallelTraverseFilterSyntax
ParallelTraverseSyntax
ParallelUnorderedFlatSequenceOps
ParallelUnorderedSequenceOps
ParallelUnorderedTraverseOps
ParallelUnorderedTraverseSyntax
PartialOrderOps
PartialOrderSyntax
ProfunctorSyntax
ReducibleOps0
ReducibleSyntax
RepresentableSyntax
RightOps
SemigroupKSyntax
SemigroupOps
SemigroupSyntax
SemigroupalOps
SemigroupalSyntax
SeparateOps
SeqOps
SeqSyntax
SequenceFilterOps
SetOps
SetSyntax
ShowSyntax
StrongSyntax
TabulateOps
TraverseFilterSyntax
TraverseSyntax
TryOps
TrySyntax
TupleParallelSyntax
TupleSemigroupalSyntax
UniteOps
UnorderedFoldableOps
UnorderedFoldableSyntax
UnorderedTraverseSyntax
ValidatedExtension
ValidatedExtensionSyntax
ValidatedIdSyntax
ValidatedSyntax
VectorOps
VectorSyntax
WriterIdSyntax
WriterSyntax
align
all
alternative
applicative
applicativeError
apply
arrow
arrowChoice
bifoldable
bifunctor
binested
bitraverse
choice
coflatMap
comonad
compose
contravariant
contravariantMonoidal
contravariantSemigroupal
distributive
either
eitherK
eq
flatMap
foldable
functor
functorFilter
group
hash
invariant
ior
list
monad
monadError
monoid
nested
nonEmptyTraverse
option
order
parallel
partialOrder
profunctor
reducible
representable
semigroup
semigroupal
semigroupk
seq
set
show
strong
traverse
traverseFilter
try_
unorderedFoldable
unorderedTraverse
validated
vector
writer

cats.syntax

WriterIdSyntax

final class WriterIdSyntax[A] extends AnyVal

Source: writer.scala

Linear Supertypes

AnyVal, Any

Type Hierarchy

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WriterIdSyntax
AnyVal
Any

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Instance Constructors

new WriterIdSyntax(a: A)

Value Members

final def !=(arg0: Any): Boolean

Definition Classes
Any
final def ##(): Int

Definition Classes
Any
final def ==(arg0: Any): Boolean

Definition Classes
Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def getClass(): Class[_ <: AnyVal]

Definition Classes
AnyVal → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
def tell: Writer[A, Unit]
def toString(): String

Definition Classes
Any
def writer[W](w: W): Writer[W, A]

Packages

WriterIdSyntax

final class WriterIdSyntax[A] extends AnyVal

Instance Constructors

Value Members

Inherited from AnyVal

Inherited from Any

Ungrouped

Packages

WriterIdSyntax 

final class WriterIdSyntax[A] extends AnyVal

Instance Constructors

Value Members

Inherited from AnyVal

Inherited from Any

Ungrouped

WriterIdSyntax