/**
* @since 2.0.0
*/
import * as Equivalence from "./Equivalence.js";
import type { LazyArg } from "./Function.js";
import type { TypeLambda } from "./HKT.js";
import type { Inspectable } from "./Inspectable.js";
import type { Option } from "./Option.js";
import type { Pipeable } from "./Pipeable.js";
import type { Predicate, Refinement } from "./Predicate.js";
import type { Covariant, NoInfer, NotFunction } from "./Types.js";
import type * as Unify from "./Unify.js";
import * as Gen from "./Utils.js";
/**
* @category models
* @since 2.0.0
*/
export type Either<R, L = never> = Left<L, R> | Right<L, R>;
/**
* @category symbols
* @since 2.0.0
*/
export declare const TypeId: unique symbol;
/**
* @category symbols
* @since 2.0.0
*/
export type TypeId = typeof TypeId;
/**
* @category models
* @since 2.0.0
*/
export interface Left<out L, out R> extends Pipeable, Inspectable {
readonly _tag: "Left";
readonly _op: "Left";
readonly left: L;
readonly [TypeId]: {
readonly _R: Covariant<R>;
readonly _L: Covariant<L>;
};
[Unify.typeSymbol]?: unknown;
[Unify.unifySymbol]?: EitherUnify<this>;
[Unify.ignoreSymbol]?: EitherUnifyIgnore;
}
/**
* @category models
* @since 2.0.0
*/
export interface Right<out L, out R> extends Pipeable, Inspectable {
readonly _tag: "Right";
readonly _op: "Right";
readonly right: R;
readonly [TypeId]: {
readonly _R: Covariant<R>;
readonly _L: Covariant<L>;
};
[Unify.typeSymbol]?: unknown;
[Unify.unifySymbol]?: EitherUnify<this>;
[Unify.ignoreSymbol]?: EitherUnifyIgnore;
}
/**
* @category models
* @since 2.0.0
*/
export interface EitherUnify<A extends {
[Unify.typeSymbol]?: any;
}> {
Either?: () => A[Unify.typeSymbol] extends Either<infer R0, infer L0> | infer _ ? Either<R0, L0> : never;
}
/**
* @category models
* @since 2.0.0
*/
export interface EitherUnifyIgnore {
}
/**
* @category type lambdas
* @since 2.0.0
*/
export interface EitherTypeLambda extends TypeLambda {
readonly type: Either<this["Target"], this["Out1"]>;
}
/**
* @since 2.0.0
*/
export declare namespace Either {
/**
* @since 2.0.0
* @category type-level
*/
type Left<T extends Either<any, any>> = [T] extends [Either<infer _A, infer _E>] ? _E : never;
/**
* @since 2.0.0
* @category type-level
*/
type Right<T extends Either<any, any>> = [T] extends [Either<infer _A, infer _E>] ? _A : never;
}
/**
* Constructs a new `Either` holding a `Right` value. This usually represents a successful value due to the right bias
* of this structure.
*
* @category constructors
* @since 2.0.0
*/
export declare const right: <R>(right: R) => Either<R>;
declare const void_: Either<void>;
export {
/**
* @category constructors
* @since 3.13.0
*/
void_ as void };
/**
* Constructs a new `Either` holding a `Left` value. This usually represents a failure, due to the right-bias of this
* structure.
*
* @category constructors
* @since 2.0.0
*/
export declare const left: <L>(left: L) => Either<never, L>;
/**
* Takes a lazy default and a nullable value, if the value is not nully (`null` or `undefined`), turn it into a `Right`, if the value is nully use
* the provided default as a `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.fromNullable(1, () => 'fallback'), Either.right(1))
* assert.deepStrictEqual(Either.fromNullable(null, () => 'fallback'), Either.left('fallback'))
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const fromNullable: {
/**
* Takes a lazy default and a nullable value, if the value is not nully (`null` or `undefined`), turn it into a `Right`, if the value is nully use
* the provided default as a `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.fromNullable(1, () => 'fallback'), Either.right(1))
* assert.deepStrictEqual(Either.fromNullable(null, () => 'fallback'), Either.left('fallback'))
* ```
*
* @category constructors
* @since 2.0.0
*/
<R, L>(onNullable: (right: R) => L): (self: R) => Either<NonNullable<R>, L>;
/**
* Takes a lazy default and a nullable value, if the value is not nully (`null` or `undefined`), turn it into a `Right`, if the value is nully use
* the provided default as a `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.fromNullable(1, () => 'fallback'), Either.right(1))
* assert.deepStrictEqual(Either.fromNullable(null, () => 'fallback'), Either.left('fallback'))
* ```
*
* @category constructors
* @since 2.0.0
*/
<R, L>(self: R, onNullable: (right: R) => L): Either<NonNullable<R>, L>;
};
/**
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, Option } from "effect"
*
* assert.deepStrictEqual(Either.fromOption(Option.some(1), () => 'error'), Either.right(1))
* assert.deepStrictEqual(Either.fromOption(Option.none(), () => 'error'), Either.left('error'))
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const fromOption: {
/**
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, Option } from "effect"
*
* assert.deepStrictEqual(Either.fromOption(Option.some(1), () => 'error'), Either.right(1))
* assert.deepStrictEqual(Either.fromOption(Option.none(), () => 'error'), Either.left('error'))
* ```
*
* @category constructors
* @since 2.0.0
*/
<L>(onNone: () => L): <R>(self: Option<R>) => Either<R, L>;
/**
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, Option } from "effect"
*
* assert.deepStrictEqual(Either.fromOption(Option.some(1), () => 'error'), Either.right(1))
* assert.deepStrictEqual(Either.fromOption(Option.none(), () => 'error'), Either.left('error'))
* ```
*
* @category constructors
* @since 2.0.0
*/
<R, L>(self: Option<R>, onNone: () => L): Either<R, L>;
};
declare const try_: {
<R, L>(options: {
readonly try: LazyArg<R>;
readonly catch: (error: unknown) => L;
}): Either<R, L>;
<R>(evaluate: LazyArg<R>): Either<R, unknown>;
};
export {
/**
* Imports a synchronous side-effect into a pure `Either` value, translating any
* thrown exceptions into typed failed eithers creating with `Either.left`.
*
* @category constructors
* @since 2.0.0
*/
try_ as try };
/**
* Tests if a value is a `Either`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.isEither(Either.right(1)), true)
* assert.deepStrictEqual(Either.isEither(Either.left("a")), true)
* assert.deepStrictEqual(Either.isEither({ right: 1 }), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isEither: (input: unknown) => input is Either<unknown, unknown>;
/**
* Determine if a `Either` is a `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.isLeft(Either.right(1)), false)
* assert.deepStrictEqual(Either.isLeft(Either.left("a")), true)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isLeft: <R, L>(self: Either<R, L>) => self is Left<L, R>;
/**
* Determine if a `Either` is a `Right`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.isRight(Either.right(1)), true)
* assert.deepStrictEqual(Either.isRight(Either.left("a")), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isRight: <R, L>(self: Either<R, L>) => self is Right<L, R>;
/**
* Converts a `Either` to an `Option` discarding the `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, Option } from "effect"
*
* assert.deepStrictEqual(Either.getRight(Either.right('ok')), Option.some('ok'))
* assert.deepStrictEqual(Either.getRight(Either.left('err')), Option.none())
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const getRight: <R, L>(self: Either<R, L>) => Option<R>;
/**
* Converts a `Either` to an `Option` discarding the value.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, Option } from "effect"
*
* assert.deepStrictEqual(Either.getLeft(Either.right('ok')), Option.none())
* assert.deepStrictEqual(Either.getLeft(Either.left('err')), Option.some('err'))
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const getLeft: <R, L>(self: Either<R, L>) => Option<L>;
/**
* @category equivalence
* @since 2.0.0
*/
export declare const getEquivalence: <R, L>({ left, right }: {
right: Equivalence.Equivalence<R>;
left: Equivalence.Equivalence<L>;
}) => Equivalence.Equivalence<Either<R, L>>;
/**
* @category mapping
* @since 2.0.0
*/
export declare const mapBoth: {
/**
* @category mapping
* @since 2.0.0
*/
<L, L2, R, R2>(options: {
readonly onLeft: (left: L) => L2;
readonly onRight: (right: R) => R2;
}): (self: Either<R, L>) => Either<R2, L2>;
/**
* @category mapping
* @since 2.0.0
*/
<L, R, L2, R2>(self: Either<R, L>, options: {
readonly onLeft: (left: L) => L2;
readonly onRight: (right: R) => R2;
}): Either<R2, L2>;
};
/**
* Maps the `Left` side of an `Either` value to a new `Either` value.
*
* @category mapping
* @since 2.0.0
*/
export declare const mapLeft: {
/**
* Maps the `Left` side of an `Either` value to a new `Either` value.
*
* @category mapping
* @since 2.0.0
*/
<L, L2>(f: (left: L) => L2): <R>(self: Either<R, L>) => Either<R, L2>;
/**
* Maps the `Left` side of an `Either` value to a new `Either` value.
*
* @category mapping
* @since 2.0.0
*/
<R, L, L2>(self: Either<R, L>, f: (left: L) => L2): Either<R, L2>;
};
/**
* Maps the `Right` side of an `Either` value to a new `Either` value.
*
* @category mapping
* @since 2.0.0
*/
export declare const map: {
/**
* Maps the `Right` side of an `Either` value to a new `Either` value.
*
* @category mapping
* @since 2.0.0
*/
<R, R2>(f: (right: R) => R2): <L>(self: Either<R, L>) => Either<R2, L>;
/**
* Maps the `Right` side of an `Either` value to a new `Either` value.
*
* @category mapping
* @since 2.0.0
*/
<R, L, R2>(self: Either<R, L>, f: (right: R) => R2): Either<R2, L>;
};
/**
* Takes two functions and an `Either` value, if the value is a `Left` the inner value is applied to the `onLeft function,
* if the value is a `Right` the inner value is applied to the `onRight` function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const onLeft = (strings: ReadonlyArray<string>): string => `strings: ${strings.join(', ')}`
*
* const onRight = (value: number): string => `Ok: ${value}`
*
* assert.deepStrictEqual(pipe(Either.right(1), Either.match({ onLeft, onRight })), 'Ok: 1')
* assert.deepStrictEqual(
* pipe(Either.left(['string 1', 'string 2']), Either.match({ onLeft, onRight })),
* 'strings: string 1, string 2'
* )
* ```
*
* @category pattern matching
* @since 2.0.0
*/
export declare const match: {
/**
* Takes two functions and an `Either` value, if the value is a `Left` the inner value is applied to the `onLeft function,
* if the value is a `Right` the inner value is applied to the `onRight` function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const onLeft = (strings: ReadonlyArray<string>): string => `strings: ${strings.join(', ')}`
*
* const onRight = (value: number): string => `Ok: ${value}`
*
* assert.deepStrictEqual(pipe(Either.right(1), Either.match({ onLeft, onRight })), 'Ok: 1')
* assert.deepStrictEqual(
* pipe(Either.left(['string 1', 'string 2']), Either.match({ onLeft, onRight })),
* 'strings: string 1, string 2'
* )
* ```
*
* @category pattern matching
* @since 2.0.0
*/
<L, B, R, C = B>(options: {
readonly onLeft: (left: L) => B;
readonly onRight: (right: R) => C;
}): (self: Either<R, L>) => B | C;
/**
* Takes two functions and an `Either` value, if the value is a `Left` the inner value is applied to the `onLeft function,
* if the value is a `Right` the inner value is applied to the `onRight` function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const onLeft = (strings: ReadonlyArray<string>): string => `strings: ${strings.join(', ')}`
*
* const onRight = (value: number): string => `Ok: ${value}`
*
* assert.deepStrictEqual(pipe(Either.right(1), Either.match({ onLeft, onRight })), 'Ok: 1')
* assert.deepStrictEqual(
* pipe(Either.left(['string 1', 'string 2']), Either.match({ onLeft, onRight })),
* 'strings: string 1, string 2'
* )
* ```
*
* @category pattern matching
* @since 2.0.0
*/
<R, L, B, C = B>(self: Either<R, L>, options: {
readonly onLeft: (left: L) => B;
readonly onRight: (right: R) => C;
}): B | C;
};
/**
* Transforms a `Predicate` function into a `Right` of the input value if the predicate returns `true`
* or `Left` of the result of the provided function if the predicate returns false
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
* const isPositiveEither = Either.liftPredicate(isPositive, n => `${n} is not positive`)
*
* assert.deepStrictEqual(
* isPositiveEither(1),
* Either.right(1)
* )
* assert.deepStrictEqual(
* isPositiveEither(0),
* Either.left("0 is not positive")
* )
* ```
*
* @category lifting
* @since 3.4.0
*/
export declare const liftPredicate: {
/**
* Transforms a `Predicate` function into a `Right` of the input value if the predicate returns `true`
* or `Left` of the result of the provided function if the predicate returns false
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
* const isPositiveEither = Either.liftPredicate(isPositive, n => `${n} is not positive`)
*
* assert.deepStrictEqual(
* isPositiveEither(1),
* Either.right(1)
* )
* assert.deepStrictEqual(
* isPositiveEither(0),
* Either.left("0 is not positive")
* )
* ```
*
* @category lifting
* @since 3.4.0
*/
<A, B extends A, E>(refinement: Refinement<A, B>, orLeftWith: (a: A) => E): (a: A) => Either<B, E>;
/**
* Transforms a `Predicate` function into a `Right` of the input value if the predicate returns `true`
* or `Left` of the result of the provided function if the predicate returns false
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
* const isPositiveEither = Either.liftPredicate(isPositive, n => `${n} is not positive`)
*
* assert.deepStrictEqual(
* isPositiveEither(1),
* Either.right(1)
* )
* assert.deepStrictEqual(
* isPositiveEither(0),
* Either.left("0 is not positive")
* )
* ```
*
* @category lifting
* @since 3.4.0
*/
<B extends A, E, A = B>(predicate: Predicate<A>, orLeftWith: (a: A) => E): (a: B) => Either<B, E>;
/**
* Transforms a `Predicate` function into a `Right` of the input value if the predicate returns `true`
* or `Left` of the result of the provided function if the predicate returns false
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
* const isPositiveEither = Either.liftPredicate(isPositive, n => `${n} is not positive`)
*
* assert.deepStrictEqual(
* isPositiveEither(1),
* Either.right(1)
* )
* assert.deepStrictEqual(
* isPositiveEither(0),
* Either.left("0 is not positive")
* )
* ```
*
* @category lifting
* @since 3.4.0
*/
<A, E, B extends A>(self: A, refinement: Refinement<A, B>, orLeftWith: (a: A) => E): Either<B, E>;
/**
* Transforms a `Predicate` function into a `Right` of the input value if the predicate returns `true`
* or `Left` of the result of the provided function if the predicate returns false
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
* const isPositiveEither = Either.liftPredicate(isPositive, n => `${n} is not positive`)
*
* assert.deepStrictEqual(
* isPositiveEither(1),
* Either.right(1)
* )
* assert.deepStrictEqual(
* isPositiveEither(0),
* Either.left("0 is not positive")
* )
* ```
*
* @category lifting
* @since 3.4.0
*/
<B extends A, E, A = B>(self: B, predicate: Predicate<A>, orLeftWith: (a: A) => E): Either<B, E>;
};
/**
* Filter the right value with the provided function.
* If the predicate fails, set the left value with the result of the provided function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
*
* assert.deepStrictEqual(
* pipe(
* Either.right(1),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* Either.right(0),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.left("0 is not positive")
* )
* ```
*
* @since 2.0.0
* @category filtering & conditionals
*/
export declare const filterOrLeft: {
/**
* Filter the right value with the provided function.
* If the predicate fails, set the left value with the result of the provided function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
*
* assert.deepStrictEqual(
* pipe(
* Either.right(1),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* Either.right(0),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.left("0 is not positive")
* )
* ```
*
* @since 2.0.0
* @category filtering & conditionals
*/
<R, B extends R, L2>(refinement: Refinement<NoInfer<R>, B>, orLeftWith: (right: NoInfer<R>) => L2): <L>(self: Either<R, L>) => Either<B, L2 | L>;
/**
* Filter the right value with the provided function.
* If the predicate fails, set the left value with the result of the provided function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
*
* assert.deepStrictEqual(
* pipe(
* Either.right(1),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* Either.right(0),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.left("0 is not positive")
* )
* ```
*
* @since 2.0.0
* @category filtering & conditionals
*/
<R, L2>(predicate: Predicate<NoInfer<R>>, orLeftWith: (right: NoInfer<R>) => L2): <L>(self: Either<R, L>) => Either<R, L2 | L>;
/**
* Filter the right value with the provided function.
* If the predicate fails, set the left value with the result of the provided function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
*
* assert.deepStrictEqual(
* pipe(
* Either.right(1),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* Either.right(0),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.left("0 is not positive")
* )
* ```
*
* @since 2.0.0
* @category filtering & conditionals
*/
<R, L, B extends R, L2>(self: Either<R, L>, refinement: Refinement<R, B>, orLeftWith: (right: R) => L2): Either<B, L | L2>;
/**
* Filter the right value with the provided function.
* If the predicate fails, set the left value with the result of the provided function.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { pipe, Either } from "effect"
*
* const isPositive = (n: number): boolean => n > 0
*
* assert.deepStrictEqual(
* pipe(
* Either.right(1),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* Either.right(0),
* Either.filterOrLeft(isPositive, n => `${n} is not positive`)
* ),
* Either.left("0 is not positive")
* )
* ```
*
* @since 2.0.0
* @category filtering & conditionals
*/
<R, L, E2>(self: Either<R, L>, predicate: Predicate<R>, orLeftWith: (right: R) => E2): Either<R, L | E2>;
};
/**
* @category getters
* @since 2.0.0
*/
export declare const merge: <R, L>(self: Either<R, L>) => L | R;
/**
* Returns the wrapped value if it's a `Right` or a default value if is a `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.getOrElse(Either.right(1), (error) => error + "!"), 1)
* assert.deepStrictEqual(Either.getOrElse(Either.left("not a number"), (error) => error + "!"), "not a number!")
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const getOrElse: {
/**
* Returns the wrapped value if it's a `Right` or a default value if is a `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.getOrElse(Either.right(1), (error) => error + "!"), 1)
* assert.deepStrictEqual(Either.getOrElse(Either.left("not a number"), (error) => error + "!"), "not a number!")
* ```
*
* @category getters
* @since 2.0.0
*/
<L, R2>(onLeft: (left: L) => R2): <R>(self: Either<R, L>) => R2 | R;
/**
* Returns the wrapped value if it's a `Right` or a default value if is a `Left`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.getOrElse(Either.right(1), (error) => error + "!"), 1)
* assert.deepStrictEqual(Either.getOrElse(Either.left("not a number"), (error) => error + "!"), "not a number!")
* ```
*
* @category getters
* @since 2.0.0
*/
<R, L, R2>(self: Either<R, L>, onLeft: (left: L) => R2): R | R2;
};
/**
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.getOrNull(Either.right(1)), 1)
* assert.deepStrictEqual(Either.getOrNull(Either.left("a")), null)
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const getOrNull: <R, L>(self: Either<R, L>) => R | null;
/**
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.getOrUndefined(Either.right(1)), 1)
* assert.deepStrictEqual(Either.getOrUndefined(Either.left("a")), undefined)
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const getOrUndefined: <R, L>(self: Either<R, L>) => R | undefined;
/**
* Extracts the value of an `Either` or throws if the `Either` is `Left`.
*
* If a default error is sufficient for your use case and you don't need to configure the thrown error, see {@link getOrThrow}.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(
* Either.getOrThrowWith(Either.right(1), () => new Error('Unexpected Left')),
* 1
* )
* assert.throws(() => Either.getOrThrowWith(Either.left("error"), () => new Error('Unexpected Left')))
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const getOrThrowWith: {
/**
* Extracts the value of an `Either` or throws if the `Either` is `Left`.
*
* If a default error is sufficient for your use case and you don't need to configure the thrown error, see {@link getOrThrow}.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(
* Either.getOrThrowWith(Either.right(1), () => new Error('Unexpected Left')),
* 1
* )
* assert.throws(() => Either.getOrThrowWith(Either.left("error"), () => new Error('Unexpected Left')))
* ```
*
* @category getters
* @since 2.0.0
*/
<L>(onLeft: (left: L) => unknown): <A>(self: Either<A, L>) => A;
/**
* Extracts the value of an `Either` or throws if the `Either` is `Left`.
*
* If a default error is sufficient for your use case and you don't need to configure the thrown error, see {@link getOrThrow}.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(
* Either.getOrThrowWith(Either.right(1), () => new Error('Unexpected Left')),
* 1
* )
* assert.throws(() => Either.getOrThrowWith(Either.left("error"), () => new Error('Unexpected Left')))
* ```
*
* @category getters
* @since 2.0.0
*/
<R, L>(self: Either<R, L>, onLeft: (left: L) => unknown): R;
};
/**
* Extracts the value of an `Either` or throws if the `Either` is `Left`.
*
* The thrown error is a default error. To configure the error thrown, see {@link getOrThrowWith}.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.getOrThrow(Either.right(1)), 1)
* assert.throws(() => Either.getOrThrow(Either.left("error")))
* ```
*
* @throws `Error("getOrThrow called on a Left")`
*
* @category getters
* @since 2.0.0
*/
export declare const getOrThrow: <R, L>(self: Either<R, L>) => R;
/**
* Returns `self` if it is a `Right` or `that` otherwise.
*
* @category error handling
* @since 2.0.0
*/
export declare const orElse: {
/**
* Returns `self` if it is a `Right` or `that` otherwise.
*
* @category error handling
* @since 2.0.0
*/
<L, R2, L2>(that: (left: L) => Either<R2, L2>): <R>(self: Either<R, L>) => Either<R | R2, L2>;
/**
* Returns `self` if it is a `Right` or `that` otherwise.
*
* @category error handling
* @since 2.0.0
*/
<R, L, R2, L2>(self: Either<R, L>, that: (left: L) => Either<R2, L2>): Either<R | R2, L2>;
};
/**
* @category sequencing
* @since 2.0.0
*/
export declare const flatMap: {
/**
* @category sequencing
* @since 2.0.0
*/
<R, R2, L2>(f: (right: R) => Either<R2, L2>): <L>(self: Either<R, L>) => Either<R2, L | L2>;
/**
* @category sequencing
* @since 2.0.0
*/
<R, L, R2, L2>(self: Either<R, L>, f: (right: R) => Either<R2, L2>): Either<R2, L | L2>;
};
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
export declare const andThen: {
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R, R2, L2>(f: (right: R) => Either<R2, L2>): <L>(self: Either<R, L>) => Either<R2, L | L2>;
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R2, L2>(f: Either<R2, L2>): <L, R1>(self: Either<R1, L>) => Either<R2, L | L2>;
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R, R2>(f: (right: R) => R2): <L>(self: Either<R, L>) => Either<R2, L>;
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R2>(right: NotFunction<R2>): <R1, L>(self: Either<R1, L>) => Either<R2, L>;
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R, L, R2, L2>(self: Either<R, L>, f: (right: R) => Either<R2, L2>): Either<R2, L | L2>;
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R, L, R2, L2>(self: Either<R, L>, f: Either<R2, L2>): Either<R2, L | L2>;
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R, L, R2>(self: Either<R, L>, f: (right: R) => R2): Either<R2, L>;
/**
* Executes a sequence of two `Either`s. The second `Either` can be dependent on the result of the first `Either`.
*
* @category sequencing
* @since 2.0.0
*/
<R, L, R2>(self: Either<R, L>, f: NotFunction<R2>): Either<R2, L>;
};
/**
* @category zipping
* @since 2.0.0
*/
export declare const zipWith: {
/**
* @category zipping
* @since 2.0.0
*/
<R2, L2, R, B>(that: Either<R2, L2>, f: (right: R, right2: R2) => B): <L>(self: Either<R, L>) => Either<B, L2 | L>;
/**
* @category zipping
* @since 2.0.0
*/
<R, L, R2, L2, B>(self: Either<R, L>, that: Either<R2, L2>, f: (right: R, right2: R2) => B): Either<B, L | L2>;
};
/**
* @category combining
* @since 2.0.0
*/
export declare const ap: {
/**
* @category combining
* @since 2.0.0
*/
<R, L2>(that: Either<R, L2>): <R2, L>(self: Either<(right: R) => R2, L>) => Either<R2, L | L2>;
/**
* @category combining
* @since 2.0.0
*/
<R, R2, L, L2>(self: Either<(right: R) => R2, L>, that: Either<R, L2>): Either<R2, L | L2>;
};
/**
* Takes a structure of `Either`s and returns an `Either` of values with the same structure.
*
* - If a tuple is supplied, then the returned `Either` will contain a tuple with the same length.
* - If a struct is supplied, then the returned `Either` will contain a struct with the same keys.
* - If an iterable is supplied, then the returned `Either` will contain an array.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either } from "effect"
*
* assert.deepStrictEqual(Either.all([Either.right(1), Either.right(2)]), Either.right([1, 2]))
* assert.deepStrictEqual(Either.all({ right: Either.right(1), b: Either.right("hello") }), Either.right({ right: 1, b: "hello" }))
* assert.deepStrictEqual(Either.all({ right: Either.right(1), b: Either.left("error") }), Either.left("error"))
* ```
*
* @category combining
* @since 2.0.0
*/
export declare const all: <const I extends Iterable<Either<any, any>> | Record<string, Either<any, any>>>(input: I) => [I] extends [ReadonlyArray<Either<any, any>>] ? Either<{
-readonly [K in keyof I]: [I[K]] extends [Either<infer R, any>] ? R : never;
}, I[number] extends never ? never : [I[number]] extends [Either<any, infer L>] ? L : never> : [I] extends [Iterable<Either<infer R, infer L>>] ? Either<Array<R>, L> : Either<{
-readonly [K in keyof I]: [I[K]] extends [Either<infer R, any>] ? R : never;
}, I[keyof I] extends never ? never : [I[keyof I]] extends [Either<any, infer L>] ? L : never>;
/**
* Returns an `Either` that swaps the error/success cases. This allows you to
* use all methods on the error channel, possibly before flipping back.
*
* @since 2.0.0
* @category mapping
*/
export declare const flip: <R, L>(self: Either<R, L>) => Either<L, R>;
/**
* @category generators
* @since 2.0.0
*/
export declare const gen: Gen.Gen<EitherTypeLambda, Gen.Adapter<EitherTypeLambda>>;
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link bind}
* @see {@link bindTo}
* @see {@link let_ let}
*
* @category do notation
* @since 2.0.0
*/
export declare const Do: Either<{}>;
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link Do}
* @see {@link bindTo}
* @see {@link let_ let}
*
* @category do notation
* @since 2.0.0
*/
export declare const bind: {
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link Do}
* @see {@link bindTo}
* @see {@link let_ let}
*
* @category do notation
* @since 2.0.0
*/
<N extends string, A extends object, B, L2>(name: Exclude<N, keyof A>, f: (a: NoInfer<A>) => Either<B, L2>): <L1>(self: Either<A, L1>) => Either<{
[K in N | keyof A]: K extends keyof A ? A[K] : B;
}, L1 | L2>;
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link Do}
* @see {@link bindTo}
* @see {@link let_ let}
*
* @category do notation
* @since 2.0.0
*/
<A extends object, L1, N extends string, B, L2>(self: Either<A, L1>, name: Exclude<N, keyof A>, f: (a: NoInfer<A>) => Either<B, L2>): Either<{
[K in N | keyof A]: K extends keyof A ? A[K] : B;
}, L1 | L2>;
};
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link Do}
* @see {@link bind}
* @see {@link let_ let}
*
* @category do notation
* @since 2.0.0
*/
export declare const bindTo: {
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link Do}
* @see {@link bind}
* @see {@link let_ let}
*
* @category do notation
* @since 2.0.0
*/
<N extends string>(name: N): <R, L>(self: Either<R, L>) => Either<{
[K in N]: R;
}, L>;
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link Do}
* @see {@link bind}
* @see {@link let_ let}
*
* @category do notation
* @since 2.0.0
*/
<R, L, N extends string>(self: Either<R, L>, name: N): Either<{
[K in N]: R;
}, L>;
};
declare const let_: {
<N extends string, R extends object, B>(name: Exclude<N, keyof R>, f: (r: NoInfer<R>) => B): <L>(self: Either<R, L>) => Either<{
[K in N | keyof R]: K extends keyof R ? R[K] : B;
}, L>;
<R extends object, L, N extends string, B>(self: Either<R, L>, name: Exclude<N, keyof R>, f: (r: NoInfer<R>) => B): Either<{
[K in N | keyof R]: K extends keyof R ? R[K] : B;
}, L>;
};
export {
/**
* The "do simulation" in Effect allows you to write code in a more declarative style, similar to the "do notation" in other programming languages. It provides a way to define variables and perform operations on them using functions like `bind` and `let`.
*
* Here's how the do simulation works:
*
* 1. Start the do simulation using the `Do` value
* 2. Within the do simulation scope, you can use the `bind` function to define variables and bind them to `Either` values
* 3. You can accumulate multiple `bind` statements to define multiple variables within the scope
* 4. Inside the do simulation scope, you can also use the `let` function to define variables and bind them to simple values
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Either, pipe } from "effect"
*
* const result = pipe(
* Either.Do,
* Either.bind("x", () => Either.right(2)),
* Either.bind("y", () => Either.right(3)),
* Either.let("sum", ({ x, y }) => x + y)
* )
* assert.deepStrictEqual(result, Either.right({ x: 2, y: 3, sum: 5 }))
* ```
*
* @see {@link Do}
* @see {@link bindTo}
* @see {@link bind}
*
* @category do notation
* @since 2.0.0
*/
let_ as let };
/**
* Converts an `Option` of an `Either` into an `Either` of an `Option`.
*
* **Details**
*
* This function transforms an `Option<Either<A, E>>` into an
* `Either<Option<A>, E>`. If the `Option` is `None`, the resulting `Either`
* will be a `Right` with a `None` value. If the `Option` is `Some`, the
* inner `Either` will be executed, and its result wrapped in a `Some`.
*
* @example
* ```ts
* import { Effect, Either, Option } from "effect"
*
* // ┌─── Option<Either<number, never>>
* // ▼
* const maybe = Option.some(Either.right(42))
*
* // ┌─── Either<Option<number>, never, never>
* // ▼
* const result = Either.transposeOption(maybe)
*
* console.log(Effect.runSync(result))
* // Output: { _id: 'Option', _tag: 'Some', value: 42 }
* ```
*
* @since 3.14.0
* @category Optional Wrapping & Unwrapping
*/
export declare const transposeOption: <A = never, E = never>(self: Option<Either<A, E>>) => Either<Option<A>, E>;
/**
* Applies an `Either` on an `Option` and transposes the result.
*
* **Details**
*
* If the `Option` is `None`, the resulting `Either` will immediately succeed with a `Right` value of `None`.
* If the `Option` is `Some`, the transformation function will be applied to the inner value, and its result wrapped in a `Some`.
*
* @example
* ```ts
* import { Either, Option, pipe } from "effect"
*
* // ┌─── Either<Option<number>, never>>
* // ▼
* const noneResult = pipe(
* Option.none(),
* Either.transposeMapOption(() => Either.right(42)) // will not be executed
* )
* console.log(noneResult)
* // Output: { _id: 'Either', _tag: 'Right', right: { _id: 'Option', _tag: 'None' } }
*
* // ┌─── Either<Option<number>, never>>
* // ▼
* const someRightResult = pipe(
* Option.some(42),
* Either.transposeMapOption((value) => Either.right(value * 2))
* )
* console.log(someRightResult)
* // Output: { _id: 'Either', _tag: 'Right', right: { _id: 'Option', _tag: 'Some', value: 84 } }
* ```
*
* @since 3.15.0
* @category Optional Wrapping & Unwrapping
*/
export declare const transposeMapOption: (<A, B, E = never>(f: (self: A) => Either<B, E>) => (self: Option<A>) => Either<Option<B>, E>) & (<A, B, E = never>(self: Option<A>, f: (self: A) => Either<B, E>) => Either<Option<B>, E>);
//# sourceMappingURL=Either.d.ts.map