ReaderEither overview
Added in v2.0.0
Table of contents
- Alt
- Apply
- Bifunctor
- Functor
- Monad
- MonadThrow
- Pointed
- combinators
- apFirst
- apFirstW
- apSecond
- apSecondW
- asksReaderEither
- asksReaderEitherW
- chainEitherK
- chainEitherKW
- chainFirst
- chainFirstEitherK
- chainFirstEitherKW
- chainFirstReaderK
- chainFirstReaderKW
- chainFirstW
- chainOptionK
- chainReaderK
- chainReaderKW
- filterOrElse
- filterOrElseW
- flap
- flatten
- flattenW
- fromEitherK
- fromOptionK
- fromReaderK
- local
- orElse
- orElseFirst
- orElseFirstW
- orElseW
- orLeft
- swap
- constructors
- destructors
- instances
- interop
- model
- natural transformations
- utils
Alt
alt
Identifies an associative operation on a type constructor. It is similar to Semigroup
, except that it applies to types of kind * -> *
.
Signature
export declare const alt: <R, E, A>(
that: () => ReaderEither<R, E, A>
) => (fa: ReaderEither<R, E, A>) => ReaderEither<R, E, A>
Added in v2.0.0
altW
Less strict version of alt
.
Signature
export declare const altW: <R2, E2, B>(
that: () => ReaderEither<R2, E2, B>
) => <R1, E1, A>(fa: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E2, B | A>
Added in v2.9.0
Apply
ap
Apply a function to an argument under a type constructor.
Signature
export declare const ap: <R, E, A>(
fa: ReaderEither<R, E, A>
) => <B>(fab: ReaderEither<R, E, (a: A) => B>) => ReaderEither<R, E, B>
Added in v2.0.0
apW
Less strict version of ap
.
Signature
export declare const apW: <R2, E2, A>(
fa: ReaderEither<R2, E2, A>
) => <R1, E1, B>(fab: ReaderEither<R1, E1, (a: A) => B>) => ReaderEither<R1 & R2, E2 | E1, B>
Added in v2.8.0
Bifunctor
bimap
Map a pair of functions over the two last type arguments of the bifunctor.
Signature
export declare const bimap: <E, G, A, B>(
f: (e: E) => G,
g: (a: A) => B
) => <R>(fa: ReaderEither<R, E, A>) => ReaderEither<R, G, B>
Added in v2.0.0
mapLeft
Map a function over the second type argument of a bifunctor.
Signature
export declare const mapLeft: <E, G>(f: (e: E) => G) => <R, A>(fa: ReaderEither<R, E, A>) => ReaderEither<R, G, A>
Added in v2.0.0
Functor
map
map
can be used to turn functions (a: A) => B
into functions (fa: F<A>) => F<B>
whose argument and return types use the type constructor F
to represent some computational context.
Signature
export declare const map: <A, B>(f: (a: A) => B) => <R, E>(fa: ReaderEither<R, E, A>) => ReaderEither<R, E, B>
Added in v2.0.0
Monad
chain
Composes computations in sequence, using the return value of one computation to determine the next computation.
Signature
export declare const chain: <R, E, A, B>(
f: (a: A) => ReaderEither<R, E, B>
) => (ma: ReaderEither<R, E, A>) => ReaderEither<R, E, B>
Added in v2.0.0
chainW
Less strict version of chain
.
Signature
export declare const chainW: <R2, E2, A, B>(
f: (a: A) => ReaderEither<R2, E2, B>
) => <R1, E1>(ma: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E2 | E1, B>
Added in v2.6.0
MonadThrow
throwError
Signature
export declare const throwError: <R, E, A>(e: E) => ReaderEither<R, E, A>
Added in v2.7.0
Pointed
of
Signature
export declare const of: <R, E = never, A = never>(a: A) => ReaderEither<R, E, A>
Added in v2.8.5
combinators
apFirst
Combine two effectful actions, keeping only the result of the first.
Derivable from Apply
.
Signature
export declare const apFirst: <R, E, B>(
second: ReaderEither<R, E, B>
) => <A>(first: ReaderEither<R, E, A>) => ReaderEither<R, E, A>
Added in v2.0.0
apFirstW
Less strict version of apFirst
Signature
export declare const apFirstW: <R2, E2, A, B>(
second: ReaderEither<R2, E2, B>
) => <R1, E1>(first: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E2 | E1, A>
Added in v2.12.0
apSecond
Combine two effectful actions, keeping only the result of the second.
Derivable from Apply
.
Signature
export declare const apSecond: <R, E, B>(
second: ReaderEither<R, E, B>
) => <A>(first: ReaderEither<R, E, A>) => ReaderEither<R, E, B>
Added in v2.0.0
apSecondW
Less strict version of apSecond
Signature
export declare const apSecondW: <R2, E2, A, B>(
second: ReaderEither<R2, E2, B>
) => <R1, E1>(first: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E2 | E1, B>
Added in v2.12.0
asksReaderEither
Effectfully accesses the environment.
Signature
export declare const asksReaderEither: <R, E, A>(f: (r: R) => ReaderEither<R, E, A>) => ReaderEither<R, E, A>
Added in v2.11.0
asksReaderEitherW
Less strict version of asksReaderEither
.
Signature
export declare const asksReaderEitherW: <R1, R2, E, A>(
f: (r1: R1) => ReaderEither<R2, E, A>
) => ReaderEither<R1 & R2, E, A>
Added in v2.11.0
chainEitherK
Signature
export declare const chainEitherK: <E, A, B>(
f: (a: A) => E.Either<E, B>
) => <R>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, B>
Added in v2.4.0
chainEitherKW
Less strict version of chainEitherK
.
Signature
export declare const chainEitherKW: <E2, A, B>(
f: (a: A) => E.Either<E2, B>
) => <R, E1>(ma: ReaderEither<R, E1, A>) => ReaderEither<R, E2 | E1, B>
Added in v2.6.1
chainFirst
Composes computations in sequence, using the return value of one computation to determine the next computation and keeping only the result of the first.
Derivable from Chain
.
Signature
export declare const chainFirst: <R, E, A, B>(
f: (a: A) => ReaderEither<R, E, B>
) => (ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A>
Added in v2.0.0
chainFirstEitherK
Signature
export declare const chainFirstEitherK: <A, E, B>(
f: (a: A) => E.Either<E, B>
) => <R>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A>
Added in v2.12.0
chainFirstEitherKW
Less strict version of chainFirstEitherK
.
Signature
export declare const chainFirstEitherKW: <A, E2, B>(
f: (a: A) => E.Either<E2, B>
) => <R, E1>(ma: ReaderEither<R, E1, A>) => ReaderEither<R, E2 | E1, A>
Added in v2.12.0
chainFirstReaderK
Signature
export declare const chainFirstReaderK: <A, R, B>(
f: (a: A) => R.Reader<R, B>
) => <E = never>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A>
Added in v2.11.0
chainFirstReaderKW
Less strict version of chainReaderK
.
Signature
export declare const chainFirstReaderKW: <A, R1, B>(
f: (a: A) => R.Reader<R1, B>
) => <R2, E = never>(ma: ReaderEither<R2, E, A>) => ReaderEither<R1 & R2, E, A>
Added in v2.11.0
chainFirstW
Less strict version of chainFirst
Derivable from Chain
.
Signature
export declare const chainFirstW: <R2, E2, A, B>(
f: (a: A) => ReaderEither<R2, E2, B>
) => <R1, E1>(ma: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E2 | E1, A>
Added in v2.8.0
chainOptionK
Signature
export declare const chainOptionK: <E>(
onNone: Lazy<E>
) => <A, B>(f: (a: A) => Option<B>) => <R>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, B>
Added in v2.10.0
chainReaderK
Signature
export declare const chainReaderK: <A, R, B>(
f: (a: A) => R.Reader<R, B>
) => <E = never>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, B>
Added in v2.11.0
chainReaderKW
Less strict version of chainReaderK
.
Signature
export declare const chainReaderKW: <A, R2, B>(
f: (a: A) => R.Reader<R2, B>
) => <R1, E = never>(ma: ReaderEither<R1, E, A>) => ReaderEither<R1 & R2, E, B>
Added in v2.11.0
filterOrElse
Signature
export declare const filterOrElse: {
<E, A, B extends A>(refinement: Refinement<A, B>, onFalse: (a: A) => E): <R>(
ma: ReaderEither<R, E, A>
) => ReaderEither<R, E, B>
<E, A>(predicate: Predicate<A>, onFalse: (a: A) => E): <R, B extends A>(
mb: ReaderEither<R, E, B>
) => ReaderEither<R, E, B>
<E, A>(predicate: Predicate<A>, onFalse: (a: A) => E): <R>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A>
}
Added in v2.0.0
filterOrElseW
Less strict version of filterOrElse
.
Signature
export declare const filterOrElseW: {
<A, B extends A, E2>(refinement: Refinement<A, B>, onFalse: (a: A) => E2): <R, E1>(
ma: ReaderEither<R, E1, A>
) => ReaderEither<R, E2 | E1, B>
<A, E2>(predicate: Predicate<A>, onFalse: (a: A) => E2): <R, E1, B extends A>(
mb: ReaderEither<R, E1, B>
) => ReaderEither<R, E2 | E1, B>
<A, E2>(predicate: Predicate<A>, onFalse: (a: A) => E2): <R, E1>(
ma: ReaderEither<R, E1, A>
) => ReaderEither<R, E2 | E1, A>
}
Added in v2.9.0
flap
Derivable from Functor
.
Signature
export declare const flap: <A>(a: A) => <R, E, B>(fab: ReaderEither<R, E, (a: A) => B>) => ReaderEither<R, E, B>
Added in v2.10.0
flatten
Derivable from Chain
.
Signature
export declare const flatten: <R, E, A>(mma: ReaderEither<R, E, ReaderEither<R, E, A>>) => ReaderEither<R, E, A>
Added in v2.0.0
flattenW
Less strict version of flatten
.
Signature
export declare const flattenW: <R1, R2, E1, E2, A>(
mma: ReaderEither<R1, E1, ReaderEither<R2, E2, A>>
) => ReaderEither<R1 & R2, E1 | E2, A>
Added in v2.11.0
fromEitherK
Signature
export declare const fromEitherK: <E, A extends readonly unknown[], B>(
f: (...a: A) => E.Either<E, B>
) => <R>(...a: A) => ReaderEither<R, E, B>
Added in v2.4.0
fromOptionK
Signature
export declare const fromOptionK: <E>(
onNone: Lazy<E>
) => <A, B>(f: (...a: A) => Option<B>) => <R>(...a: A) => ReaderEither<R, E, B>
Added in v2.10.0
fromReaderK
Signature
export declare const fromReaderK: <A extends readonly unknown[], R, B>(
f: (...a: A) => R.Reader<R, B>
) => <E = never>(...a: A) => ReaderEither<R, E, B>
Added in v2.11.0
local
Changes the value of the local context during the execution of the action ma
(similar to Contravariant
’s contramap
).
Signature
export declare const local: <R2, R1>(f: (r2: R2) => R1) => <E, A>(ma: ReaderEither<R1, E, A>) => ReaderEither<R2, E, A>
Added in v2.0.0
orElse
Signature
export declare const orElse: <E1, R, E2, A>(
onLeft: (e: E1) => ReaderEither<R, E2, A>
) => (ma: ReaderEither<R, E1, A>) => ReaderEither<R, E2, A>
Added in v2.0.0
orElseFirst
Signature
export declare const orElseFirst: <E, R, B>(
onLeft: (e: E) => ReaderEither<R, E, B>
) => <A>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A>
Added in v2.11.0
orElseFirstW
Signature
export declare const orElseFirstW: <E1, R2, E2, B>(
onLeft: (e: E1) => ReaderEither<R2, E2, B>
) => <R1, A>(ma: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E1 | E2, A>
Added in v2.11.0
orElseW
Less strict version of orElse
.
Signature
export declare const orElseW: <E1, R1, E2, B>(
onLeft: (e: E1) => ReaderEither<R1, E2, B>
) => <R2, A>(ma: ReaderEither<R2, E1, A>) => ReaderEither<R1 & R2, E2, B | A>
Added in v2.10.0
orLeft
Signature
export declare const orLeft: <E1, R, E2>(
onLeft: (e: E1) => R.Reader<R, E2>
) => <A>(fa: ReaderEither<R, E1, A>) => ReaderEither<R, E2, A>
Added in v2.11.0
swap
Signature
export declare const swap: <R, E, A>(ma: ReaderEither<R, E, A>) => ReaderEither<R, A, E>
Added in v2.0.0
constructors
ask
Reads the current context.
Signature
export declare const ask: <R, E = never>() => ReaderEither<R, E, R>
Added in v2.0.0
asks
Projects a value from the global context in a ReaderEither
.
Signature
export declare const asks: <R, A, E = never>(f: (r: R) => A) => ReaderEither<R, E, A>
Added in v2.0.0
fromPredicate
Signature
export declare const fromPredicate: {
<E, A, B extends A>(refinement: Refinement<A, B>, onFalse: (a: A) => E): <R>(a: A) => ReaderEither<R, E, B>
<E, A>(predicate: Predicate<A>, onFalse: (a: A) => E): <R, B extends A>(b: B) => ReaderEither<R, E, B>
<E, A>(predicate: Predicate<A>, onFalse: (a: A) => E): <R>(a: A) => ReaderEither<R, E, A>
}
Added in v2.0.0
left
Signature
export declare const left: <R, E = never, A = never>(e: E) => ReaderEither<R, E, A>
Added in v2.0.0
leftReader
Signature
export declare const leftReader: <R, E = never, A = never>(me: R.Reader<R, E>) => ReaderEither<R, E, A>
Added in v2.0.0
right
Signature
export declare const right: <R, E = never, A = never>(a: A) => ReaderEither<R, E, A>
Added in v2.0.0
rightReader
Signature
export declare const rightReader: <R, E = never, A = never>(ma: R.Reader<R, A>) => ReaderEither<R, E, A>
Added in v2.0.0
destructors
fold
Alias of matchE
.
Signature
export declare const fold: <R, E, A, B>(
onLeft: (e: E) => R.Reader<R, B>,
onRight: (a: A) => R.Reader<R, B>
) => (ma: ReaderEither<R, E, A>) => R.Reader<R, B>
Added in v2.0.0
foldW
Alias of matchEW
.
Signature
export declare const foldW: <E, R2, B, A, R3, C>(
onLeft: (e: E) => R.Reader<R2, B>,
onRight: (a: A) => R.Reader<R3, C>
) => <R1>(ma: ReaderEither<R1, E, A>) => R.Reader<R1 & R2 & R3, B | C>
Added in v2.10.0
getOrElse
Signature
export declare const getOrElse: <E, R, A>(
onLeft: (e: E) => R.Reader<R, A>
) => (ma: ReaderEither<R, E, A>) => R.Reader<R, A>
Added in v2.0.0
getOrElseW
Less strict version of getOrElse
.
Signature
export declare const getOrElseW: <R2, E, B>(
onLeft: (e: E) => R.Reader<R2, B>
) => <R1, A>(ma: ReaderEither<R1, E, A>) => R.Reader<R1 & R2, B | A>
Added in v2.6.0
match
Signature
export declare const match: <E, B, A>(
onLeft: (e: E) => B,
onRight: (a: A) => B
) => <R>(ma: ReaderEither<R, E, A>) => R.Reader<R, B>
Added in v2.10.0
matchE
Signature
export declare const matchE: <R, E, A, B>(
onLeft: (e: E) => R.Reader<R, B>,
onRight: (a: A) => R.Reader<R, B>
) => (ma: ReaderEither<R, E, A>) => R.Reader<R, B>
Added in v2.10.0
matchEW
Less strict version of matchE
.
Signature
export declare const matchEW: <E, R2, B, A, R3, C>(
onLeft: (e: E) => R.Reader<R2, B>,
onRight: (a: A) => R.Reader<R3, C>
) => <R1>(ma: ReaderEither<R1, E, A>) => R.Reader<R1 & R2 & R3, B | C>
Added in v2.10.0
matchW
Less strict version of match
.
Signature
export declare const matchW: <E, B, A, C>(
onLeft: (e: E) => B,
onRight: (a: A) => C
) => <R>(ma: R.Reader<R, E.Either<E, A>>) => R.Reader<R, B | C>
Added in v2.10.0
instances
Alt
Signature
export declare const Alt: Alt3<'ReaderEither'>
Added in v2.7.0
Applicative
Signature
export declare const Applicative: Applicative3<'ReaderEither'>
Added in v2.7.0
Apply
Signature
export declare const Apply: Apply3<'ReaderEither'>
Added in v2.10.0
Bifunctor
Signature
export declare const Bifunctor: Bifunctor3<'ReaderEither'>
Added in v2.7.0
Chain
Signature
export declare const Chain: Chain3<'ReaderEither'>
Added in v2.10.0
FromEither
Signature
export declare const FromEither: FromEither3<'ReaderEither'>
Added in v2.10.0
FromReader
Signature
export declare const FromReader: FromReader3<'ReaderEither'>
Added in v2.11.0
Functor
Signature
export declare const Functor: Functor3<'ReaderEither'>
Added in v2.7.0
Monad
Signature
export declare const Monad: Monad3<'ReaderEither'>
Added in v2.7.0
MonadThrow
Signature
export declare const MonadThrow: MonadThrow3<'ReaderEither'>
Added in v2.7.0
Pointed
Signature
export declare const Pointed: Pointed3<'ReaderEither'>
Added in v2.10.0
URI
Signature
export declare const URI: 'ReaderEither'
Added in v2.0.0
URI (type alias)
Signature
export type URI = typeof URI
Added in v2.0.0
getAltReaderValidation
Signature
export declare function getAltReaderValidation<E>(S: Semigroup<E>): Alt3C<URI, E>
Added in v2.7.0
getApplicativeReaderValidation
Signature
export declare function getApplicativeReaderValidation<E>(S: Semigroup<E>): Applicative3C<URI, E>
Added in v2.7.0
getCompactable
Signature
export declare const getCompactable: <E>(M: Monoid<E>) => Compactable3C<'ReaderEither', E>
Added in v2.10.0
getFilterable
Signature
export declare function getFilterable<E>(M: Monoid<E>): Filterable3C<URI, E>
Added in v2.10.0
getApplyMonoid
Use getApplicativeMonoid
instead.
Signature
export declare const getApplyMonoid: <R, E, A>(M: Monoid<A>) => Monoid<ReaderEither<R, E, A>>
Added in v2.0.0
getApplySemigroup
Use getApplySemigroup
instead.
Signature
export declare const getApplySemigroup: <R, E, A>(S: Semigroup<A>) => Semigroup<ReaderEither<R, E, A>>
Added in v2.0.0
getReaderValidation
Use getApplicativeReaderValidation
and getAltReaderValidation
instead.
Signature
export declare function getReaderValidation<E>(
SE: Semigroup<E>
): Monad3C<URI, E> & Bifunctor3<URI> & Alt3C<URI, E> & MonadThrow3C<URI, E>
Added in v2.3.0
getSemigroup
Use getApplySemigroup
instead.
Signature
export declare const getSemigroup: <R, E, A>(S: Semigroup<A>) => Semigroup<ReaderEither<R, E, A>>
Added in v2.0.0
readerEither
Use small, specific instances instead.
Signature
export declare const readerEither: Monad3<'ReaderEither'> &
Bifunctor3<'ReaderEither'> &
Alt3<'ReaderEither'> &
MonadThrow3<'ReaderEither'>
Added in v2.0.0
interop
toUnion
Signature
export declare const toUnion: <R, E, A>(fa: ReaderEither<R, E, A>) => R.Reader<R, E | A>
Added in v2.10.0
model
ReaderEither (interface)
Signature
export interface ReaderEither<R, E, A> extends Reader<R, Either<E, A>> {}
Added in v2.0.0
natural transformations
fromEither
Signature
export declare const fromEither: NaturalTransformation23<'Either', 'ReaderEither'>
Added in v2.0.0
fromOption
Signature
export declare const fromOption: <E>(onNone: Lazy<E>) => NaturalTransformation13C<'Option', 'ReaderEither', E>
Added in v2.0.0
fromReader
Signature
export declare const fromReader: NaturalTransformation23R<'Reader', 'ReaderEither'>
Added in v2.11.0
utils
ApT
Signature
export declare const ApT: ReaderEither<unknown, never, readonly []>
Added in v2.11.0
Do
Signature
export declare const Do: ReaderEither<unknown, never, {}>
Added in v2.9.0
apS
Signature
export declare const apS: <N, A, R, E, B>(
name: Exclude<N, keyof A>,
fb: ReaderEither<R, E, B>
) => (fa: ReaderEither<R, E, A>) => ReaderEither<R, E, { readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>
Added in v2.8.0
apSW
Signature
export declare const apSW: <A, N extends string, R2, E2, B>(
name: Exclude<N, keyof A>,
fb: ReaderEither<R2, E2, B>
) => <R1, E1>(
fa: ReaderEither<R1, E1, A>
) => ReaderEither<R1 & R2, E2 | E1, { readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>
Added in v2.8.0
bind
Signature
export declare const bind: <N, A, R, E, B>(
name: Exclude<N, keyof A>,
f: (a: A) => ReaderEither<R, E, B>
) => (ma: ReaderEither<R, E, A>) => ReaderEither<R, E, { readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>
Added in v2.8.0
bindTo
Signature
export declare const bindTo: <N>(
name: N
) => <R, E, A>(fa: ReaderEither<R, E, A>) => ReaderEither<R, E, { readonly [K in N]: A }>
Added in v2.8.0
bindW
Signature
export declare const bindW: <N extends string, A, R2, E2, B>(
name: Exclude<N, keyof A>,
f: (a: A) => ReaderEither<R2, E2, B>
) => <R1, E1>(
fa: ReaderEither<R1, E1, A>
) => ReaderEither<R1 & R2, E2 | E1, { readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>
Added in v2.8.0
sequenceArray
Signature
export declare const sequenceArray: <R, E, A>(arr: readonly ReaderEither<R, E, A>[]) => ReaderEither<R, E, readonly A[]>
Added in v2.9.0
traverseArray
Signature
export declare const traverseArray: <R, E, A, B>(
f: (a: A) => ReaderEither<R, E, B>
) => (as: readonly A[]) => ReaderEither<R, E, readonly B[]>
Added in v2.9.0
traverseArrayWithIndex
Signature
export declare const traverseArrayWithIndex: <R, E, A, B>(
f: (index: number, a: A) => ReaderEither<R, E, B>
) => (as: readonly A[]) => ReaderEither<R, E, readonly B[]>
Added in v2.9.0
traverseReadonlyArrayWithIndex
Equivalent to ReadonlyArray#traverseWithIndex(Applicative)
.
Signature
export declare const traverseReadonlyArrayWithIndex: <A, R, E, B>(
f: (index: number, a: A) => ReaderEither<R, E, B>
) => (as: readonly A[]) => ReaderEither<R, E, readonly B[]>
Added in v2.11.0
traverseReadonlyNonEmptyArrayWithIndex
Equivalent to ReadonlyNonEmptyArray#traverseWithIndex(Applicative)
.
Signature
export declare const traverseReadonlyNonEmptyArrayWithIndex: <A, R, E, B>(
f: (index: number, a: A) => ReaderEither<R, E, B>
) => (as: ReadonlyNonEmptyArray<A>) => ReaderEither<R, E, ReadonlyNonEmptyArray<B>>
Added in v2.11.0