ReaderEither.ts

/**
 * @since 2.0.0
 */
import { Alt3, Alt3C } from './Alt'
import { Applicative3, Applicative3C, getApplicativeMonoid } from './Applicative'
import {
  ap as ap_,
  apFirst as apFirst_,
  Apply3,
  apS as apS_,
  apSecond as apSecond_,
  getApplySemigroup as getApplySemigroup_
} from './Apply'
import { Bifunctor3 } from './Bifunctor'
import { bind as bind_, Chain3, chainFirst as chainFirst_ } from './Chain'
import { compact as compact_, Compactable3C, separate as separate_ } from './Compactable'
import * as E from './Either'
import * as ET from './EitherT'
import {
  filter as filter_,
  Filterable3C,
  filterMap as filterMap_,
  partition as partition_,
  partitionMap as partitionMap_
} from './Filterable'
import {
  chainEitherK as chainEitherK_,
  chainOptionK as chainOptionK_,
  filterOrElse as filterOrElse_,
  FromEither3,
  fromEitherK as fromEitherK_,
  fromOption as fromOption_,
  fromOptionK as fromOptionK_,
  fromPredicate as fromPredicate_
} from './FromEither'
import {
  ask as ask_,
  asks as asks_,
  chainFirstReaderK as chainFirstReaderK_,
  chainReaderK as chainReaderK_,
  FromReader3,
  fromReaderK as fromReaderK_
} from './FromReader'
import { flow, identity, Lazy, pipe, SK } from './function'
import { bindTo as bindTo_, flap as flap_, Functor3 } from './Functor'
import * as _ from './internal'
import { Monad3, Monad3C } from './Monad'
import { MonadThrow3, MonadThrow3C } from './MonadThrow'
import { Monoid } from './Monoid'
import { NaturalTransformation13C } from './NaturalTransformation'
import { URI as OURI } from './Option'
import { Pointed3 } from './Pointed'
import { Predicate } from './Predicate'
import * as R from './Reader'
import { ReadonlyNonEmptyArray } from './ReadonlyNonEmptyArray'
import { Refinement } from './Refinement'
import { Semigroup } from './Semigroup'

import Reader = R.Reader
import Either = E.Either

// -------------------------------------------------------------------------------------
// model
// -------------------------------------------------------------------------------------

/**
 * @category model
 * @since 2.0.0
 */
export interface ReaderEither<R, E, A> extends Reader<R, Either<E, A>> {}

// -------------------------------------------------------------------------------------
// constructors
// -------------------------------------------------------------------------------------

/**
 * @category constructors
 * @since 2.0.0
 */
export const left: <R, E = never, A = never>(e: E) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  ET.left(R.Pointed)

/**
 * @category constructors
 * @since 2.0.0
 */
export const right: <R, E = never, A = never>(a: A) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  ET.right(R.Pointed)

/**
 * @category constructors
 * @since 2.0.0
 */
export const rightReader: <R, E = never, A = never>(ma: Reader<R, A>) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  ET.rightF(R.Functor)

/**
 * @category constructors
 * @since 2.0.0
 */
export const leftReader: <R, E = never, A = never>(me: Reader<R, E>) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  ET.leftF(R.Functor)

// -------------------------------------------------------------------------------------
// natural transformations
// -------------------------------------------------------------------------------------

/**
 * @category natural transformations
 * @since 2.0.0
 */
export const fromEither: FromEither3<URI>['fromEither'] = R.of

/**
 * @category natural transformations
 * @since 2.11.0
 */
export const fromReader: FromReader3<URI>['fromReader'] = rightReader

// -------------------------------------------------------------------------------------
// destructors
// -------------------------------------------------------------------------------------

/**
 * @category destructors
 * @since 2.10.0
 */
export const match: <E, B, A>(
  onLeft: (e: E) => B,
  onRight: (a: A) => B
) => <R>(ma: ReaderEither<R, E, A>) => Reader<R, B> =
  /*#__PURE__*/
  ET.match(R.Functor)

/**
 * Less strict version of [`match`](#match).
 *
 * @category destructors
 * @since 2.10.0
 */
export const matchW: <E, B, A, C>(
  onLeft: (e: E) => B,
  onRight: (a: A) => C
) => <R>(ma: Reader<R, Either<E, A>>) => Reader<R, B | C> = match as any

/**
 * @category destructors
 * @since 2.10.0
 */
export const matchE: <R, E, A, B>(
  onLeft: (e: E) => Reader<R, B>,
  onRight: (a: A) => Reader<R, B>
) => (ma: ReaderEither<R, E, A>) => Reader<R, B> =
  /*#__PURE__*/
  ET.matchE(R.Monad)

/**
 * Alias of [`matchE`](#matche).
 *
 * @category destructors
 * @since 2.0.0
 */
export const fold = matchE

/**
 * Less strict version of [`matchE`](#matche).
 *
 * @category destructors
 * @since 2.10.0
 */
export const matchEW: <E, R2, B, A, R3, C>(
  onLeft: (e: E) => Reader<R2, B>,
  onRight: (a: A) => Reader<R3, C>
) => <R1>(ma: ReaderEither<R1, E, A>) => Reader<R1 & R2 & R3, B | C> = matchE as any

/**
 * Alias of [`matchEW`](#matchew).
 *
 * @category destructors
 * @since 2.10.0
 */
export const foldW = matchEW

/**
 * @category destructors
 * @since 2.0.0
 */
export const getOrElse: <E, R, A>(onLeft: (e: E) => Reader<R, A>) => (ma: ReaderEither<R, E, A>) => Reader<R, A> =
  /*#__PURE__*/
  ET.getOrElse(R.Monad)

/**
 * Less strict version of [`getOrElse`](#getorelse).
 *
 * @category destructors
 * @since 2.6.0
 */
export const getOrElseW: <R2, E, B>(
  onLeft: (e: E) => Reader<R2, B>
) => <R1, A>(ma: ReaderEither<R1, E, A>) => Reader<R1 & R2, A | B> = getOrElse as any

// -------------------------------------------------------------------------------------
// interop
// -------------------------------------------------------------------------------------

/**
 * @category interop
 * @since 2.10.0
 */
export const toUnion: <R, E, A>(fa: ReaderEither<R, E, A>) => Reader<R, E | A> =
  /*#__PURE__*/
  ET.toUnion(R.Functor)

// -------------------------------------------------------------------------------------
// combinators
// -------------------------------------------------------------------------------------

/**
 * Changes the value of the local context during the execution of the action `ma` (similar to `Contravariant`'s
 * `contramap`).
 *
 * @category combinators
 * @since 2.0.0
 */
export const local: <R2, R1>(f: (r2: R2) => R1) => <E, A>(ma: ReaderEither<R1, E, A>) => ReaderEither<R2, E, A> =
  R.local

/**
 * Less strict version of [`asksReaderEither`](#asksreadereither).
 *
 * @category combinators
 * @since 2.11.0
 */
export const asksReaderEitherW: <R1, R2, E, A>(f: (r1: R1) => ReaderEither<R2, E, A>) => ReaderEither<R1 & R2, E, A> =
  R.asksReaderW

/**
 * Effectfully accesses the environment.
 *
 * @category combinators
 * @since 2.11.0
 */
export const asksReaderEither: <R, E, A>(
  f: (r: R) => ReaderEither<R, E, A>
) => ReaderEither<R, E, A> = asksReaderEitherW

/**
 * @category combinators
 * @since 2.0.0
 */
export const orElse: <E1, R, E2, A>(
  onLeft: (e: E1) => ReaderEither<R, E2, A>
) => (ma: ReaderEither<R, E1, A>) => ReaderEither<R, E2, A> =
  /*#__PURE__*/
  ET.orElse(R.Monad)

/**
 * Less strict version of [`orElse`](#orelse).
 *
 * @category combinators
 * @since 2.10.0
 */
export const orElseW: <E1, R1, E2, B>(
  onLeft: (e: E1) => ReaderEither<R1, E2, B>
) => <R2, A>(ma: ReaderEither<R2, E1, A>) => ReaderEither<R1 & R2, E2, A | B> = orElse as any

/**
 * @category combinators
 * @since 2.11.0
 */
export const orElseFirst: <E, R, B>(
  onLeft: (e: E) => ReaderEither<R, E, B>
) => <A>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  ET.orElseFirst(R.Monad)

/**
 * @category combinators
 * @since 2.11.0
 */
export const orElseFirstW: <E1, R, E2, B>(
  onLeft: (e: E1) => ReaderEither<R, E2, B>
) => <A>(ma: ReaderEither<R, E1, A>) => ReaderEither<R, E1 | E2, A> = orElseFirst as any

/**
 * @category combinators
 * @since 2.11.0
 */
export const orLeft: <E1, R, E2>(
  onLeft: (e: E1) => Reader<R, E2>
) => <A>(fa: ReaderEither<R, E1, A>) => ReaderEither<R, E2, A> =
  /*#__PURE__*/
  ET.orLeft(R.Monad)

/**
 * @category combinators
 * @since 2.0.0
 */
export const swap: <R, E, A>(ma: ReaderEither<R, E, A>) => ReaderEither<R, A, E> =
  /*#__PURE__*/
  ET.swap(R.Functor)

// -------------------------------------------------------------------------------------
// non-pipeables
// -------------------------------------------------------------------------------------

/* istanbul ignore next */
const _map: Monad3<URI>['map'] = (fa, f) => pipe(fa, map(f))
/* istanbul ignore next */
const _bimap: Bifunctor3<URI>['bimap'] = (fa, f, g) => pipe(fa, bimap(f, g))
/* istanbul ignore next */
const _mapLeft: Bifunctor3<URI>['mapLeft'] = (fa, f) => pipe(fa, mapLeft(f))
/* istanbul ignore next */
const _ap: Monad3<URI>['ap'] = (fab, fa) => pipe(fab, ap(fa))
/* istanbul ignore next */
const _chain: Monad3<URI>['chain'] = (ma, f) => pipe(ma, chain(f))
/* istanbul ignore next */
const _alt: Alt3<URI>['alt'] = (fa, that) => pipe(fa, alt(that))

// -------------------------------------------------------------------------------------
// type class members
// -------------------------------------------------------------------------------------

/**
 * `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.
 *
 * @category Functor
 * @since 2.0.0
 */
export const map: <A, B>(f: (a: A) => B) => <R, E>(fa: ReaderEither<R, E, A>) => ReaderEither<R, E, B> =
  /*#__PURE__*/
  ET.map(R.Functor)

/**
 * Map a pair of functions over the two last type arguments of the bifunctor.
 *
 * @category Bifunctor
 * @since 2.0.0
 */
export const bimap: <E, G, A, B>(
  f: (e: E) => G,
  g: (a: A) => B
) => <R>(fa: ReaderEither<R, E, A>) => ReaderEither<R, G, B> =
  /*#__PURE__*/
  ET.bimap(R.Functor)

/**
 * Map a function over the second type argument of a bifunctor.
 *
 * @category Bifunctor
 * @since 2.0.0
 */
export const mapLeft: <E, G>(f: (e: E) => G) => <R, A>(fa: ReaderEither<R, E, A>) => ReaderEither<R, G, A> =
  /*#__PURE__*/
  ET.mapLeft(R.Functor)

/**
 * Apply a function to an argument under a type constructor.
 *
 * @category Apply
 * @since 2.0.0
 */
export const ap: <R, E, A>(
  fa: ReaderEither<R, E, A>
) => <B>(fab: ReaderEither<R, E, (a: A) => B>) => ReaderEither<R, E, B> =
  /*#__PURE__*/
  ET.ap(R.Apply)

/**
 * Less strict version of [`ap`](#ap).
 *
 * @category Apply
 * @since 2.8.0
 */
export const apW: <R2, E2, A>(
  fa: ReaderEither<R2, E2, A>
) => <R1, E1, B>(fab: ReaderEither<R1, E1, (a: A) => B>) => ReaderEither<R1 & R2, E1 | E2, B> = ap as any

/**
 * @category Pointed
 * @since 2.8.5
 */
export const of: <R, E = never, A = never>(a: A) => ReaderEither<R, E, A> = right

/**
 * Composes computations in sequence, using the return value of one computation to determine the next computation.
 *
 * @category Monad
 * @since 2.0.0
 */
export const chain: <R, E, A, B>(
  f: (a: A) => ReaderEither<R, E, B>
) => (ma: ReaderEither<R, E, A>) => ReaderEither<R, E, B> =
  /*#__PURE__*/
  ET.chain(R.Monad)

/**
 * Less strict version of [`chain`](#chain).
 *
 * @category Monad
 * @since 2.6.0
 */
export const chainW: <R2, E2, A, B>(
  f: (a: A) => ReaderEither<R2, E2, B>
) => <R1, E1>(ma: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E1 | E2, B> = chain as any

/**
 * Less strict version of [`flatten`](#flatten).
 *
 * @category combinators
 * @since 2.11.0
 */
export const flattenW: <R1, R2, E1, E2, A>(
  mma: ReaderEither<R1, E1, ReaderEither<R2, E2, A>>
) => ReaderEither<R1 & R2, E1 | E2, A> =
  /*#__PURE__*/
  chainW(identity)

/**
 * Derivable from `Chain`.
 *
 * @category combinators
 * @since 2.0.0
 */
export const flatten: <R, E, A>(mma: ReaderEither<R, E, ReaderEither<R, E, A>>) => ReaderEither<R, E, A> = flattenW

/**
 * Identifies an associative operation on a type constructor. It is similar to `Semigroup`, except that it applies to
 * types of kind `* -> *`.
 *
 * @category Alt
 * @since 2.0.0
 */
export const alt: <R, E, A>(that: () => ReaderEither<R, E, A>) => (fa: ReaderEither<R, E, A>) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  ET.alt(R.Monad)

/**
 * Less strict version of [`alt`](#alt).
 *
 * @category Alt
 * @since 2.9.0
 */
export const altW: <R2, E2, B>(
  that: () => ReaderEither<R2, E2, B>
) => <R1, E1, A>(fa: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E2, A | B> = alt as any

/**
 * @category MonadThrow
 * @since 2.7.0
 */
export const throwError: MonadThrow3<URI>['throwError'] = left

// -------------------------------------------------------------------------------------
// instances
// -------------------------------------------------------------------------------------

/**
 * @category instances
 * @since 2.0.0
 */
export const URI = 'ReaderEither'

/**
 * @category instances
 * @since 2.0.0
 */
export type URI = typeof URI

declare module './HKT' {
  interface URItoKind3<R, E, A> {
    readonly [URI]: ReaderEither<R, E, A>
  }
}

/**
 * @category instances
 * @since 2.10.0
 */
export const getCompactable = <E>(M: Monoid<E>): Compactable3C<URI, E> => {
  const C = E.getCompactable(M)
  return {
    URI,
    _E: undefined as any,
    compact: compact_(R.Functor, C),
    separate: separate_(R.Functor, C, E.Functor)
  }
}

/**
 * @category instances
 * @since 2.10.0
 */
export function getFilterable<E>(M: Monoid<E>): Filterable3C<URI, E> {
  const F = E.getFilterable(M)
  const C = getCompactable(M)

  const filter = filter_(R.Functor, F)
  const filterMap = filterMap_(R.Functor, F)
  const partition = partition_(R.Functor, F)
  const partitionMap = partitionMap_(R.Functor, F)
  return {
    URI,
    _E: undefined as any,
    map: _map,
    compact: C.compact,
    separate: C.separate,
    filter: <R, A>(fa: ReaderEither<R, E, A>, predicate: Predicate<A>) => pipe(fa, filter(predicate)),
    filterMap: (fa, f) => pipe(fa, filterMap(f)),
    partition: <R, A>(fa: ReaderEither<R, E, A>, predicate: Predicate<A>) => pipe(fa, partition(predicate)),
    partitionMap: (fa, f) => pipe(fa, partitionMap(f))
  }
}

/**
 * @category instances
 * @since 2.7.0
 */
export function getApplicativeReaderValidation<E>(S: Semigroup<E>): Applicative3C<URI, E> {
  const ap = ap_(R.Apply, E.getApplicativeValidation(S))
  return {
    URI,
    _E: undefined as any,
    map: _map,
    ap: (fab, fa) => pipe(fab, ap(fa)),
    of
  }
}

/**
 * @category instances
 * @since 2.7.0
 */
export function getAltReaderValidation<E>(S: Semigroup<E>): Alt3C<URI, E> {
  const alt = ET.altValidation(R.Monad, S)
  return {
    URI,
    _E: undefined as any,
    map: _map,
    alt: (fa, that) => pipe(fa, alt(that))
  }
}

/**
 * @category instances
 * @since 2.7.0
 */
export const Functor: Functor3<URI> = {
  URI,
  map: _map
}

/**
 * Derivable from `Functor`.
 *
 * @category combinators
 * @since 2.10.0
 */
export const flap =
  /*#__PURE__*/
  flap_(Functor)

/**
 * @category instances
 * @since 2.10.0
 */
export const Pointed: Pointed3<URI> = {
  URI,
  of
}

/**
 * @category instances
 * @since 2.10.0
 */
export const Apply: Apply3<URI> = {
  URI,
  map: _map,
  ap: _ap
}

/**
 * Combine two effectful actions, keeping only the result of the first.
 *
 * Derivable from `Apply`.
 *
 * @category combinators
 * @since 2.0.0
 */
export const apFirst =
  /*#__PURE__*/
  apFirst_(Apply)

/**
 * Less strict version of [`apFirst`](#apfirst)
 *
 * @category combinators
 * @since 2.12.0
 */
export const apFirstW: <R2, E2, A, B>(
  second: ReaderEither<R2, E2, B>
) => <R1, E1>(first: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E1 | E2, A> = apFirst as any

/**
 * Combine two effectful actions, keeping only the result of the second.
 *
 * Derivable from `Apply`.
 *
 * @category combinators
 * @since 2.0.0
 */
export const apSecond =
  /*#__PURE__*/
  apSecond_(Apply)

/**
 * Less strict version of [`apSecond`](#apsecond)
 *
 * @category combinators
 * @since 2.12.0
 */
export const apSecondW: <R2, E2, A, B>(
  second: ReaderEither<R2, E2, B>
) => <R1, E1>(first: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E1 | E2, B> = apSecond as any

/**
 * @category instances
 * @since 2.7.0
 */
export const Applicative: Applicative3<URI> = {
  URI,
  map: _map,
  ap: _ap,
  of
}

/**
 * @category instances
 * @since 2.10.0
 */
export const Chain: Chain3<URI> = {
  URI,
  map: _map,
  ap: _ap,
  chain: _chain
}

/**
 * @category instances
 * @since 2.7.0
 */
export const Monad: Monad3<URI> = {
  URI,
  map: _map,
  ap: _ap,
  of,
  chain: _chain
}

/**
 * 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`.
 *
 * @category combinators
 * @since 2.0.0
 */
export const chainFirst: <R, E, A, B>(
  f: (a: A) => ReaderEither<R, E, B>
) => (ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  chainFirst_(Chain)

/**
 * Less strict version of [`chainFirst`](#chainfirst)
 *
 * Derivable from `Chain`.
 *
 * @category combinators
 * @since 2.8.0
 */
export const chainFirstW: <R2, E2, A, B>(
  f: (a: A) => ReaderEither<R2, E2, B>
) => <R1, E1>(ma: ReaderEither<R1, E1, A>) => ReaderEither<R1 & R2, E1 | E2, A> = chainFirst as any

/**
 * @category instances
 * @since 2.7.0
 */
export const Bifunctor: Bifunctor3<URI> = {
  URI,
  bimap: _bimap,
  mapLeft: _mapLeft
}

/**
 * @category instances
 * @since 2.7.0
 */
export const Alt: Alt3<URI> = {
  URI,
  map: _map,
  alt: _alt
}

/**
 * @category instances
 * @since 2.11.0
 */
export const FromReader: FromReader3<URI> = {
  URI,
  fromReader
}

/**
 * Reads the current context.
 *
 * @category constructors
 * @since 2.0.0
 */
export const ask: <R, E = never>() => ReaderEither<R, E, R> =
  /*#__PURE__*/
  ask_(FromReader)

/**
 * Projects a value from the global context in a `ReaderEither`.
 *
 * @category constructors
 * @since 2.0.0
 */
export const asks: <R, A, E = never>(f: (r: R) => A) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  asks_(FromReader)

/**
 * @category combinators
 * @since 2.11.0
 */
export const fromReaderK: <A extends ReadonlyArray<unknown>, R, B>(
  f: (...a: A) => Reader<R, B>
) => <E = never>(...a: A) => ReaderEither<R, E, B> =
  /*#__PURE__*/
  fromReaderK_(FromReader)

/**
 * @category combinators
 * @since 2.11.0
 */
export const chainReaderK: <A, R, B>(
  f: (a: A) => Reader<R, B>
) => <E = never>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, B> =
  /*#__PURE__*/
  chainReaderK_(FromReader, Chain)

/**
 * Less strict version of [`chainReaderK`](#chainreaderk).
 *
 * @category combinators
 * @since 2.11.0
 */
export const chainReaderKW: <A, R2, B>(
  f: (a: A) => Reader<R2, B>
) => <R1, E = never>(ma: ReaderEither<R1, E, A>) => ReaderEither<R1 & R2, E, B> = chainReaderK as any

/**
 * @category combinators
 * @since 2.11.0
 */
export const chainFirstReaderK: <A, R, B>(
  f: (a: A) => Reader<R, B>
) => <E = never>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, A> =
  /*#__PURE__*/
  chainFirstReaderK_(FromReader, Chain)

/**
 * Less strict version of [`chainReaderK`](#chainreaderk).
 *
 * @category combinators
 * @since 2.11.0
 */
export const chainFirstReaderKW: <A, R1, B>(
  f: (a: A) => Reader<R1, B>
) => <R2, E = never>(ma: ReaderEither<R2, E, A>) => ReaderEither<R1 & R2, E, A> = chainFirstReaderK as any

/**
 * @category instances
 * @since 2.7.0
 */
export const MonadThrow: MonadThrow3<URI> = {
  URI,
  map: _map,
  ap: _ap,
  of,
  chain: _chain,
  throwError
}

/**
 * @category instances
 * @since 2.10.0
 */
export const FromEither: FromEither3<URI> = {
  URI,
  fromEither
}

/**
 * @category natural transformations
 * @since 2.0.0
 */
export const fromOption: <E>(onNone: Lazy<E>) => NaturalTransformation13C<OURI, URI, E> =
  /*#__PURE__*/
  fromOption_(FromEither)

/**
 * @category combinators
 * @since 2.10.0
 */
export const fromOptionK =
  /*#__PURE__*/
  fromOptionK_(FromEither)

/**
 * @category combinators
 * @since 2.10.0
 */
export const chainOptionK =
  /*#__PURE__*/
  chainOptionK_(FromEither, Chain)

/**
 * @category combinators
 * @since 2.4.0
 */
export const chainEitherK: <E, A, B>(
  f: (a: A) => E.Either<E, B>
) => <R>(ma: ReaderEither<R, E, A>) => ReaderEither<R, E, B> =
  /*#__PURE__*/
  chainEitherK_(FromEither, Chain)

/**
 * Less strict version of [`chainEitherK`](#chaineitherk).
 *
 * @category combinators
 * @since 2.6.1
 */
export const chainEitherKW: <E2, A, B>(
  f: (a: A) => Either<E2, B>
) => <R, E1>(ma: ReaderEither<R, E1, A>) => ReaderEither<R, E1 | E2, B> = chainEitherK as any

/**
 * @category constructors
 * @since 2.0.0
 */
export 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>
} =
  /*#__PURE__*/
  fromPredicate_(FromEither)

/**
 * @category combinators
 * @since 2.0.0
 */
export 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>
} =
  /*#__PURE__*/
  filterOrElse_(FromEither, Chain)

/**
 * Less strict version of [`filterOrElse`](#filterorelse).
 *
 * @category combinators
 * @since 2.9.0
 */
export const filterOrElseW: {
  <A, B extends A, E2>(refinement: Refinement<A, B>, onFalse: (a: A) => E2): <R, E1>(
    ma: ReaderEither<R, E1, A>
  ) => ReaderEither<R, E1 | E2, B>
  <A, E2>(predicate: Predicate<A>, onFalse: (a: A) => E2): <R, E1, B extends A>(
    mb: ReaderEither<R, E1, B>
  ) => ReaderEither<R, E1 | E2, B>
  <A, E2>(predicate: Predicate<A>, onFalse: (a: A) => E2): <R, E1>(
    ma: ReaderEither<R, E1, A>
  ) => ReaderEither<R, E1 | E2, A>
} = filterOrElse

/**
 * @category combinators
 * @since 2.4.0
 */
export const fromEitherK: <E, A extends ReadonlyArray<unknown>, B>(
  f: (...a: A) => E.Either<E, B>
) => <R>(...a: A) => ReaderEither<R, E, B> =
  /*#__PURE__*/
  fromEitherK_(FromEither)

// -------------------------------------------------------------------------------------
// do notation
// -------------------------------------------------------------------------------------

/**
 * @since 2.9.0
 */
export const Do: ReaderEither<unknown, never, {}> =
  /*#__PURE__*/
  of(_.emptyRecord)

/**
 * @since 2.8.0
 */
export const bindTo =
  /*#__PURE__*/
  bindTo_(Functor)

/**
 * @since 2.8.0
 */
export const bind =
  /*#__PURE__*/
  bind_(Chain)

/**
 * @since 2.8.0
 */
export 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, E1 | E2, { readonly [K in keyof A | N]: K extends keyof A ? A[K] : B }> = bind as any

// -------------------------------------------------------------------------------------
// pipeable sequence S
// -------------------------------------------------------------------------------------

/**
 * @since 2.8.0
 */
export const apS =
  /*#__PURE__*/
  apS_(Apply)

/**
 * @since 2.8.0
 */
export 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, E1 | E2, { readonly [K in keyof A | N]: K extends keyof A ? A[K] : B }> = apS as any

// -------------------------------------------------------------------------------------
// sequence T
// -------------------------------------------------------------------------------------

/**
 * @since 2.11.0
 */
export const ApT: ReaderEither<unknown, never, readonly []> =
  /*#__PURE__*/
  of(_.emptyReadonlyArray)

// -------------------------------------------------------------------------------------
// array utils
// -------------------------------------------------------------------------------------

/**
 * Equivalent to `ReadonlyNonEmptyArray#traverseWithIndex(Applicative)`.
 *
 * @since 2.11.0
 */
export const traverseReadonlyNonEmptyArrayWithIndex = <A, R, E, B>(
  f: (index: number, a: A) => ReaderEither<R, E, B>
): ((as: ReadonlyNonEmptyArray<A>) => ReaderEither<R, E, ReadonlyNonEmptyArray<B>>) =>
  flow(R.traverseReadonlyNonEmptyArrayWithIndex(f), R.map(E.traverseReadonlyNonEmptyArrayWithIndex(SK)))

/**
 * Equivalent to `ReadonlyArray#traverseWithIndex(Applicative)`.
 *
 * @since 2.11.0
 */
export const traverseReadonlyArrayWithIndex = <A, R, E, B>(
  f: (index: number, a: A) => ReaderEither<R, E, B>
): ((as: ReadonlyArray<A>) => ReaderEither<R, E, ReadonlyArray<B>>) => {
  const g = traverseReadonlyNonEmptyArrayWithIndex(f)
  return (as) => (_.isNonEmpty(as) ? g(as) : ApT)
}

/**
 * @since 2.9.0
 */
export const traverseArrayWithIndex: <R, E, A, B>(
  f: (index: number, a: A) => ReaderEither<R, E, B>
) => (as: ReadonlyArray<A>) => ReaderEither<R, E, ReadonlyArray<B>> = traverseReadonlyArrayWithIndex

/**
 * @since 2.9.0
 */
export const traverseArray = <R, E, A, B>(
  f: (a: A) => ReaderEither<R, E, B>
): ((as: ReadonlyArray<A>) => ReaderEither<R, E, ReadonlyArray<B>>) => traverseReadonlyArrayWithIndex((_, a) => f(a))

/**
 * @since 2.9.0
 */
export const sequenceArray: <R, E, A>(
  arr: ReadonlyArray<ReaderEither<R, E, A>>
) => ReaderEither<R, E, ReadonlyArray<A>> =
  /*#__PURE__*/
  traverseArray(identity)

// -------------------------------------------------------------------------------------
// deprecated
// -------------------------------------------------------------------------------------

// tslint:disable: deprecation

/**
 * Use small, specific instances instead.
 *
 * @category instances
 * @since 2.0.0
 * @deprecated
 */
export const readerEither: Monad3<URI> & Bifunctor3<URI> & Alt3<URI> & MonadThrow3<URI> = {
  URI,
  bimap: _bimap,
  mapLeft: _mapLeft,
  map: _map,
  of,
  ap: _ap,
  chain: _chain,
  alt: _alt,
  throwError: left
}

/**
 * Use [`getApplySemigroup`](./Apply.ts.html#getapplysemigroup) instead.
 *
 * @category instances
 * @since 2.0.0
 * @deprecated
 */
export const getApplySemigroup: <R, E, A>(S: Semigroup<A>) => Semigroup<ReaderEither<R, E, A>> =
  /*#__PURE__*/
  getApplySemigroup_(Apply)

/**
 * Use [`getApplicativeMonoid`](./Applicative.ts.html#getapplicativemonoid) instead.
 *
 * @category instances
 * @since 2.0.0
 * @deprecated
 */
export const getApplyMonoid: <R, E, A>(M: Monoid<A>) => Monoid<ReaderEither<R, E, A>> =
  /*#__PURE__*/
  getApplicativeMonoid(Applicative)

/**
 * Use [`getApplySemigroup`](./Apply.ts.html#getapplysemigroup) instead.
 *
 * @category instances
 * @since 2.0.0
 * @deprecated
 */
export const getSemigroup = <R, E, A>(S: Semigroup<A>): Semigroup<ReaderEither<R, E, A>> =>
  getApplySemigroup_(R.Apply)(E.getSemigroup(S))

/**
 * Use [`getApplicativeReaderValidation`](#getapplicativereadervalidation) and [`getAltReaderValidation`](#getaltreadervalidation) instead.
 *
 * @category instances
 * @since 2.3.0
 * @deprecated
 */
export function getReaderValidation<E>(
  SE: Semigroup<E>
): Monad3C<URI, E> & Bifunctor3<URI> & Alt3C<URI, E> & MonadThrow3C<URI, E> {
  const applicativeReaderValidation = getApplicativeReaderValidation(SE)
  const altReaderValidation = getAltReaderValidation(SE)
  return {
    URI,
    _E: undefined as any,
    map: _map,
    ap: applicativeReaderValidation.ap,
    of,
    chain: _chain,
    bimap: _bimap,
    mapLeft: _mapLeft,
    alt: altReaderValidation.alt,
    throwError
  }
}