/** * A data structure providing "inclusive-or" as opposed to `Either`'s "exclusive-or". * * If you interpret `Either<E, A>` as suggesting the computation may either fail or succeed (exclusively), then * `These<E, A>` may fail, succeed, or do both at the same time. * * There are a few ways to interpret the both case: * * - You can think of a computation that has a non-fatal error. * - You can think of a computation that went as far as it could before erroring. * - You can think of a computation that keeps track of errors as it completes. * * Another way you can think of `These<E, A>` is saying that we want to handle `E` kind of data, `A` kind of data, or * both `E` and `A` kind of data at the same time. This is particularly useful when it comes to displaying UI's. * * (description adapted from https://package.elm-lang.org/packages/joneshf/elm-these) * * Adapted from https://github.com/purescript-contrib/purescript-these * * @since 2.0.0 */ import { Applicative2C } from './Applicative' import { Apply2C } from './Apply' import { Bifunctor2 } from './Bifunctor' import { Chain2C } from './Chain' import { Either, Left, Right } from './Either' import { Eq } from './Eq' import { Foldable2 } from './Foldable' import { FromEither2 } from './FromEither' import { FromThese2 } from './FromThese' import { Lazy } from './function' import { Functor2 } from './Functor' import { Monad2C } from './Monad' import { MonadThrow2C } from './MonadThrow' import { Monoid } from './Monoid' import { Option } from './Option' import { Pointed2 } from './Pointed' import { Predicate } from './Predicate' import { ReadonlyNonEmptyArray } from './ReadonlyNonEmptyArray' import { Refinement } from './Refinement' import { Semigroup } from './Semigroup' import { Show } from './Show' import { PipeableTraverse2, Traversable2 } from './Traversable' /** * @category model * @since 2.0.0 */ export interface Both<E, A> { readonly _tag: 'Both' readonly left: E readonly right: A } /** * @category model * @since 2.0.0 */ export declare type These<E, A> = Either<E, A> | Both<E, A> /** * Returns `true` if the these is an instance of `Left`, `false` otherwise * * @category refinements * @since 2.0.0 */ export declare const isLeft: <E>(fa: These<E, unknown>) => fa is Left<E> /** * Returns `true` if the these is an instance of `Right`, `false` otherwise * * @category refinements * @since 2.0.0 */ export declare const isRight: <A>(fa: These<unknown, A>) => fa is Right<A> /** * Returns `true` if the these is an instance of `Both`, `false` otherwise * * @category refinements * @since 2.0.0 */ export declare function isBoth<E, A>(fa: These<E, A>): fa is Both<E, A> /** * @category constructors * @since 2.0.0 */ export declare function left<E = never, A = never>(left: E): These<E, A> /** * @category constructors * @since 2.0.0 */ export declare function right<E = never, A = never>(right: A): These<E, A> /** * @category constructors * @since 2.0.0 */ export declare function both<E, A>(left: E, right: A): These<E, A> /** * Less strict version of [`match`](#match). * * The `W` suffix (short for **W**idening) means that the handler return types will be merged. * * @category pattern matching * @since 2.10.0 */ export declare const matchW: <E, B, A, C, D>( onLeft: (e: E) => B, onRight: (a: A) => C, onBoth: (e: E, a: A) => D ) => (fa: These<E, A>) => B | C | D /** * Alias of [`matchW`](#matchw). * * @category pattern matching * @since 2.10.0 */ export declare const foldW: <E, B, A, C, D>( onLeft: (e: E) => B, onRight: (a: A) => C, onBoth: (e: E, a: A) => D ) => (fa: These<E, A>) => B | C | D /** * @category pattern matching * @since 2.10.0 */ export declare const match: <E, A, B>( onLeft: (e: E) => B, onRight: (a: A) => B, onBoth: (e: E, a: A) => B ) => (fa: These<E, A>) => B /** * Alias of [`match`](#match). * * @category pattern matching * @since 2.0.0 */ export declare const fold: <E, A, B>( onLeft: (e: E) => B, onRight: (a: A) => B, onBoth: (e: E, a: A) => B ) => (fa: These<E, A>) => B /** * @since 2.4.0 */ export declare const swap: <E, A>(fa: These<E, A>) => These<A, E> /** * @category instances * @since 2.0.0 */ export declare function getShow<E, A>(SE: Show<E>, SA: Show<A>): Show<These<E, A>> /** * @category instances * @since 2.0.0 */ export declare function getEq<E, A>(EE: Eq<E>, EA: Eq<A>): Eq<These<E, A>> /** * @category instances * @since 2.0.0 */ export declare function getSemigroup<E, A>(SE: Semigroup<E>, SA: Semigroup<A>): Semigroup<These<E, A>> /** * @category instances * @since 2.10.0 */ export declare const getApply: <E>(S: Semigroup<E>) => Apply2C<'These', E> /** * @category instances * @since 2.7.0 */ export declare function getApplicative<E>(S: Semigroup<E>): Applicative2C<URI, E> /** * @category instances * @since 2.10.0 */ export declare function getChain<E>(S: Semigroup<E>): Chain2C<URI, E> /** * @category instances * @since 2.0.0 */ export declare function getMonad<E>(S: Semigroup<E>): Monad2C<URI, E> & MonadThrow2C<URI, E> /** * Returns an `E` value if possible * * @example * import { getLeft, left, right, both } from 'fp-ts/These' * import { none, some } from 'fp-ts/Option' * * assert.deepStrictEqual(getLeft(left('a')), some('a')) * assert.deepStrictEqual(getLeft(right(1)), none) * assert.deepStrictEqual(getLeft(both('a', 1)), some('a')) * * @category conversions * @since 2.0.0 */ export declare function getLeft<E, A>(fa: These<E, A>): Option<E> /** * Returns an `A` value if possible * * @example * import { getRight, left, right, both } from 'fp-ts/These' * import { none, some } from 'fp-ts/Option' * * assert.deepStrictEqual(getRight(left('a')), none) * assert.deepStrictEqual(getRight(right(1)), some(1)) * assert.deepStrictEqual(getRight(both('a', 1)), some(1)) * * @category conversions * @since 2.0.0 */ export declare function getRight<E, A>(fa: These<E, A>): Option<A> /** * @example * import { leftOrBoth, left, both } from 'fp-ts/These' * import { none, some } from 'fp-ts/Option' * * assert.deepStrictEqual(leftOrBoth('a')(none), left('a')) * assert.deepStrictEqual(leftOrBoth('a')(some(1)), both('a', 1)) * * @category constructors * @since 2.0.0 */ export declare function leftOrBoth<E>(e: E): <A>(ma: Option<A>) => These<E, A> /** * @example * import { rightOrBoth, right, both } from 'fp-ts/These' * import { none, some } from 'fp-ts/Option' * * assert.deepStrictEqual(rightOrBoth(1)(none), right(1)) * assert.deepStrictEqual(rightOrBoth(1)(some('a')), both('a', 1)) * * @category constructors * @since 2.0.0 */ export declare function rightOrBoth<A>(a: A): <E>(me: Option<E>) => These<E, A> /** * Returns the `E` value if and only if the value is constructed with `Left` * * @example * import { getLeftOnly, left, right, both } from 'fp-ts/These' * import { none, some } from 'fp-ts/Option' * * assert.deepStrictEqual(getLeftOnly(left('a')), some('a')) * assert.deepStrictEqual(getLeftOnly(right(1)), none) * assert.deepStrictEqual(getLeftOnly(both('a', 1)), none) * * @category conversions * @since 2.0.0 */ export declare function getLeftOnly<E, A>(fa: These<E, A>): Option<E> /** * Returns the `A` value if and only if the value is constructed with `Right` * * @example * import { getRightOnly, left, right, both } from 'fp-ts/These' * import { none, some } from 'fp-ts/Option' * * assert.deepStrictEqual(getRightOnly(left('a')), none) * assert.deepStrictEqual(getRightOnly(right(1)), some(1)) * assert.deepStrictEqual(getRightOnly(both('a', 1)), none) * * @category conversions * @since 2.0.0 */ export declare function getRightOnly<E, A>(fa: These<E, A>): Option<A> /** * Takes a pair of `Option`s and attempts to create a `These` from them * * @example * import { fromOptions, left, right, both } from 'fp-ts/These' * import { none, some } from 'fp-ts/Option' * * assert.deepStrictEqual(fromOptions(none, none), none) * assert.deepStrictEqual(fromOptions(some('a'), none), some(left('a'))) * assert.deepStrictEqual(fromOptions(none, some(1)), some(right(1))) * assert.deepStrictEqual(fromOptions(some('a'), some(1)), some(both('a', 1))) * * @category conversions * @since 2.0.0 */ export declare const fromOptions: <E, A>(fe: Option<E>, fa: Option<A>) => Option<These<E, A>> /** * Map a pair of functions over the two type arguments of the bifunctor. * * @category mapping * @since 2.0.0 */ export declare const bimap: <E, G, A, B>(f: (e: E) => G, g: (a: A) => B) => (fa: These<E, A>) => These<G, B> /** * Map a function over the first type argument of a bifunctor. * * @category error handling * @since 2.0.0 */ export declare const mapLeft: <E, G>(f: (e: E) => G) => <A>(fa: These<E, A>) => These<G, A> /** * `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 mapping * @since 2.0.0 */ export declare const map: <A, B>(f: (a: A) => B) => <E>(fa: These<E, A>) => These<E, B> /** * @category folding * @since 2.0.0 */ export declare const reduce: <A, B>(b: B, f: (b: B, a: A) => B) => <E>(fa: These<E, A>) => B /** * @category folding * @since 2.0.0 */ export declare const foldMap: <M>(M: Monoid<M>) => <A>(f: (a: A) => M) => <E>(fa: These<E, A>) => M /** * @category folding * @since 2.0.0 */ export declare const reduceRight: <A, B>(b: B, f: (a: A, b: B) => B) => <E>(fa: These<E, A>) => B /** * @category traversing * @since 2.6.3 */ export declare const traverse: PipeableTraverse2<URI> /** * @category traversing * @since 2.6.3 */ export declare const sequence: Traversable2<URI>['sequence'] /** * @category constructors * @since 2.0.0 */ export declare const of: <E = never, A = never>(right: A) => These<E, A> /** * @category type lambdas * @since 2.0.0 */ export declare const URI = 'These' /** * @category type lambdas * @since 2.0.0 */ export declare type URI = typeof URI declare module './HKT' { interface URItoKind2<E, A> { readonly [URI]: These<E, A> } } /** * @category instances * @since 2.7.0 */ export declare const Functor: Functor2<URI> /** * @category mapping * @since 2.10.0 */ export declare const flap: <A>(a: A) => <E, B>(fab: These<E, (a: A) => B>) => These<E, B> /** * @category instances * @since 2.10.0 */ export declare const Pointed: Pointed2<URI> /** * @category instances * @since 2.7.0 */ export declare const Bifunctor: Bifunctor2<URI> /** * @category instances * @since 2.11.0 */ export declare const FromThese: FromThese2<URI> /** * @category instances * @since 2.7.0 */ export declare const Foldable: Foldable2<URI> /** * @category instances * @since 2.7.0 */ export declare const Traversable: Traversable2<URI> /** * @category instances * @since 2.10.0 */ export declare const FromEither: FromEither2<URI> /** * @category lifting * @since 2.13.0 */ export declare const fromPredicate: { <A, B extends A, E>(refinement: Refinement<A, B>, onFalse: (a: A) => E): (a: A) => These<E, B> <A, E>(predicate: Predicate<A>, onFalse: (a: A) => E): <B extends A>(b: B) => These<E, B> <A, E>(predicate: Predicate<A>, onFalse: (a: A) => E): (a: A) => These<E, A> } /** * @category conversions * @since 2.10.0 */ export declare const fromOption: <E>(onNone: Lazy<E>) => <A>(fa: Option<A>) => These<E, A> /** * @category lifting * @since 2.10.0 */ export declare const fromOptionK: <E>( onNone: Lazy<E> ) => <A extends ReadonlyArray<unknown>, B>(f: (...a: A) => Option<B>) => (...a: A) => These<E, B> /** * @since 2.11.0 */ export declare const elem: <A>(E: Eq<A>) => (a: A) => <E>(ma: These<E, A>) => boolean /** * @since 2.11.0 */ export declare const exists: <A>(predicate: Predicate<A>) => (ma: These<unknown, A>) => boolean /** * @example * import { toTuple2, left, right, both } from 'fp-ts/These' * * assert.deepStrictEqual(toTuple2(() => 'a', () => 1)(left('b')), ['b', 1]) * assert.deepStrictEqual(toTuple2(() => 'a', () => 1)(right(2)), ['a', 2]) * assert.deepStrictEqual(toTuple2(() => 'a', () => 1)(both('b', 2)), ['b', 2]) * * @category conversions * @since 2.10.0 */ export declare const toTuple2: <E, A>(e: Lazy<E>, a: Lazy<A>) => (fa: These<E, A>) => readonly [E, A] /** * Use [`toTuple2`](#totuple2) instead. * * @category zone of death * @since 2.0.0 * @deprecated */ export declare const toTuple: <E, A>(e: E, a: A) => (fa: These<E, A>) => [E, A] /** * @since 2.11.0 */ export declare const ApT: These<never, readonly []> /** * Equivalent to `ReadonlyNonEmptyArray#traverseWithIndex(getApplicative(S))`. * * @category traversing * @since 2.11.0 */ export declare const traverseReadonlyNonEmptyArrayWithIndex: <E>( S: Semigroup<E> ) => <A, B>( f: (index: number, a: A) => These<E, B> ) => (as: ReadonlyNonEmptyArray<A>) => These<E, ReadonlyNonEmptyArray<B>> /** * Equivalent to `ReadonlyArray#traverseWithIndex(getApplicative(S))`. * * @category traversing * @since 2.11.0 */ export declare const traverseReadonlyArrayWithIndex: <E>( S: Semigroup<E> ) => <A, B>(f: (index: number, a: A) => These<E, B>) => (as: readonly A[]) => These<E, readonly B[]> /** * This instance is deprecated, use small, specific instances instead. * For example if a function needs a `Functor` instance, pass `T.Functor` instead of `T.these` * (where `T` is from `import T from 'fp-ts/These'`) * * @category zone of death * @since 2.0.0 * @deprecated */ export declare const these: Functor2<URI> & Bifunctor2<URI> & Foldable2<URI> & Traversable2<URI>