functor

package

v2.8.0 Latest Latest Go to latest Published: Oct 19, 2026 License: Apache-2.0 Imports: 1 Imported by: 0

Details

Valid go.mod file
Redistributable license
Tagged version
Stable version
Learn more about best practices

Repository

github.com/IBM/fp-go

Links

Open Source Insights

Documentation ¶

Index ¶

func Flap[FAB ~func(A) B, A, B, HKTFAB, HKTB any](fmap func(func(FAB) B) func(HKTFAB) HKTB, a A) func(HKTFAB) HKTB
func Let[S1, S2, B, HKTS1, HKTS2 any](mmap func(func(S1) S2) func(HKTS1) HKTS2, key func(B) func(S1) S2, ...) func(HKTS1) HKTS2
func LetTo[S1, S2, B, HKTS1, HKTS2 any](mmap func(func(S1) S2) func(HKTS1) HKTS2, key func(B) func(S1) S2, b B) func(HKTS1) HKTS2
func Map[A, B, HKTGA, HKTGB, HKTFGA, HKTFGB any](fmap func(func(HKTGA) HKTGB) func(HKTFGA) HKTFGB, ...) func(HKTFGA) HKTFGB
func MonadFlap[FAB ~func(A) B, A, B, HKTFAB, HKTB any](fmap func(HKTFAB, func(FAB) B) HKTB, fab HKTFAB, a A) HKTB
func MonadLet[S1, S2, B, HKTS1, HKTS2 any](mmap func(HKTS1, func(S1) S2) HKTS2, first HKTS1, key func(B) func(S1) S2, ...) HKTS2
func MonadMap[A, B, HKTGA, HKTGB, HKTFGA, HKTFGB any](fmap func(HKTFGA, func(HKTGA) HKTGB) HKTFGB, gmap func(HKTGA, func(A) B) HKTGB, ...) HKTFGB
type Functor
type MapType

Constants ¶

This section is empty.

Variables ¶

This section is empty.

Functions ¶

func Flap ¶

func Flap[FAB ~func(A) B, A, B, HKTFAB, HKTB any](
	fmap func(func(FAB) B) func(HKTFAB) HKTB,
	a A,
) func(HKTFAB) HKTB

func Let ¶

func Let[S1, S2, B, HKTS1, HKTS2 any](
	mmap func(func(S1) S2) func(HKTS1) HKTS2,
	key func(B) func(S1) S2,
	f func(S1) B,
) func(HKTS1) HKTS2

func LetTo ¶

func LetTo[S1, S2, B, HKTS1, HKTS2 any](
	mmap func(func(S1) S2) func(HKTS1) HKTS2,
	key func(B) func(S1) S2,
	b B,
) func(HKTS1) HKTS2

func Map ¶

func Map[A, B, HKTGA, HKTGB, HKTFGA, HKTFGB any](
	fmap func(func(HKTGA) HKTGB) func(HKTFGA) HKTFGB,
	gmap func(func(A) B) func(HKTGA) HKTGB,
	f func(A) B) func(HKTFGA) HKTFGB

func MonadFlap ¶

func MonadFlap[FAB ~func(A) B, A, B, HKTFAB, HKTB any](
	fmap func(HKTFAB, func(FAB) B) HKTB,

	fab HKTFAB,
	a A,
) HKTB

func MonadLet ¶

func MonadLet[S1, S2, B, HKTS1, HKTS2 any](
	mmap func(HKTS1, func(S1) S2) HKTS2,
	first HKTS1,
	key func(B) func(S1) S2,
	f func(S1) B,
) HKTS2

func MonadMap ¶

func MonadMap[A, B, HKTGA, HKTGB, HKTFGA, HKTFGB any](
	fmap func(HKTFGA, func(HKTGA) HKTGB) HKTFGB,
	gmap func(HKTGA, func(A) B) HKTGB,
	fa HKTFGA,
	f func(A) B) HKTFGB

HKTFGA = HKT[F, HKT[G, A]] HKTFGB = HKT[F, HKT[G, B]]

Types ¶

type Functor ¶

type Functor[A, B, HKTA, HKTB any] interface {
	// Map transforms the value inside the functor using the provided function,
	// preserving the structure of the functor.
	//
	// Returns a function that takes a functor containing A and returns a functor containing B.
	Map(func(A) B) func(HKTA) HKTB
}

Functor represents a type that can be mapped over, allowing transformation of values contained within a context while preserving the structure of that context.

A Functor must satisfy the following laws:

Identity:

Map(identity) == identity

Composition:

Map(f ∘ g) == Map(f) ∘ Map(g)

Type Parameters:

A: The input value type contained in the functor
B: The output value type after transformation
HKTA: The higher-kinded type containing A (e.g., Option[A], Either[E, A])
HKTB: The higher-kinded type containing B (e.g., Option[B], Either[E, B])

Example:

// Given a functor for Option[int]
var f Functor[int, string, Option[int], Option[string]]
mapFn := f.Map(strconv.Itoa)
result := mapFn(Some(42)) // Returns Some("42")

type MapType ¶ added in v2.1.13

type MapType[A, B, HKTA, HKTB any] = func(func(A) B) func(HKTA) HKTB

Source Files ¶

View all Source files

Directories ¶

Path	Synopsis
testing

?	: This menu
/	: Search site
f or F	: Jump to
y or Y	: Canonical URL