Innovenergy_trunk/frontend/node_modules/fp-ts/es6/Either.js

1435 lines
36 KiB
JavaScript

import { getApplicativeMonoid } from './Applicative';
import { apFirst as apFirst_, apS as apS_, apSecond as apSecond_, getApplySemigroup as getApplySemigroup_ } from './Apply';
import { bind as bind_, chainFirst as chainFirst_ } from './Chain';
import { tailRec } from './ChainRec';
import { chainOptionK as chainOptionK_, filterOrElse as filterOrElse_, fromOption as fromOption_, fromOptionK as fromOptionK_, fromPredicate as fromPredicate_ } from './FromEither';
import { flow, identity, pipe } from './function';
import { bindTo as bindTo_, flap as flap_, let as let__ } from './Functor';
import * as _ from './internal';
import { separated } from './Separated';
import { wiltDefault, witherDefault } from './Witherable';
// -------------------------------------------------------------------------------------
// constructors
// -------------------------------------------------------------------------------------
/**
* 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 var left = _.left;
/**
* 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 var right = _.right;
var _map = function (fa, f) { return pipe(fa, map(f)); };
var _ap = function (fab, fa) { return pipe(fab, ap(fa)); };
/* istanbul ignore next */
var _chain = function (ma, f) { return pipe(ma, chain(f)); };
/* istanbul ignore next */
var _reduce = function (fa, b, f) { return pipe(fa, reduce(b, f)); };
/* istanbul ignore next */
var _foldMap = function (M) { return function (fa, f) {
var foldMapM = foldMap(M);
return pipe(fa, foldMapM(f));
}; };
/* istanbul ignore next */
var _reduceRight = function (fa, b, f) { return pipe(fa, reduceRight(b, f)); };
var _traverse = function (F) {
var traverseF = traverse(F);
return function (ta, f) { return pipe(ta, traverseF(f)); };
};
var _bimap = function (fa, f, g) { return pipe(fa, bimap(f, g)); };
var _mapLeft = function (fa, f) { return pipe(fa, mapLeft(f)); };
/* istanbul ignore next */
var _alt = function (fa, that) { return pipe(fa, alt(that)); };
/* istanbul ignore next */
var _extend = function (wa, f) { return pipe(wa, extend(f)); };
var _chainRec = function (a, f) {
return tailRec(f(a), function (e) {
return isLeft(e) ? right(left(e.left)) : isLeft(e.right) ? left(f(e.right.left)) : right(right(e.right.right));
});
};
/**
* @category type lambdas
* @since 2.0.0
*/
export var URI = 'Either';
/**
* @category instances
* @since 2.0.0
*/
export var getShow = function (SE, SA) { return ({
show: function (ma) { return (isLeft(ma) ? "left(".concat(SE.show(ma.left), ")") : "right(".concat(SA.show(ma.right), ")")); }
}); };
/**
* @category instances
* @since 2.0.0
*/
export var getEq = function (EL, EA) { return ({
equals: function (x, y) {
return x === y || (isLeft(x) ? isLeft(y) && EL.equals(x.left, y.left) : isRight(y) && EA.equals(x.right, y.right));
}
}); };
/**
* Semigroup returning the left-most non-`Left` value. If both operands are `Right`s then the inner values are
* concatenated using the provided `Semigroup`
*
* @example
* import { getSemigroup, left, right } from 'fp-ts/Either'
* import { SemigroupSum } from 'fp-ts/number'
*
* const S = getSemigroup<string, number>(SemigroupSum)
* assert.deepStrictEqual(S.concat(left('a'), left('b')), left('a'))
* assert.deepStrictEqual(S.concat(left('a'), right(2)), right(2))
* assert.deepStrictEqual(S.concat(right(1), left('b')), right(1))
* assert.deepStrictEqual(S.concat(right(1), right(2)), right(3))
*
* @category instances
* @since 2.0.0
*/
export var getSemigroup = function (S) { return ({
concat: function (x, y) { return (isLeft(y) ? x : isLeft(x) ? y : right(S.concat(x.right, y.right))); }
}); };
/**
* Builds a `Compactable` instance for `Either` given `Monoid` for the left side.
*
* @category filtering
* @since 2.10.0
*/
export var getCompactable = function (M) {
var empty = left(M.empty);
return {
URI: URI,
_E: undefined,
compact: function (ma) { return (isLeft(ma) ? ma : ma.right._tag === 'None' ? empty : right(ma.right.value)); },
separate: function (ma) {
return isLeft(ma)
? separated(ma, ma)
: isLeft(ma.right)
? separated(right(ma.right.left), empty)
: separated(empty, right(ma.right.right));
}
};
};
/**
* Builds a `Filterable` instance for `Either` given `Monoid` for the left side
*
* @category filtering
* @since 2.10.0
*/
export var getFilterable = function (M) {
var empty = left(M.empty);
var _a = getCompactable(M), compact = _a.compact, separate = _a.separate;
var filter = function (ma, predicate) {
return isLeft(ma) ? ma : predicate(ma.right) ? ma : empty;
};
var partition = function (ma, p) {
return isLeft(ma)
? separated(ma, ma)
: p(ma.right)
? separated(empty, right(ma.right))
: separated(right(ma.right), empty);
};
return {
URI: URI,
_E: undefined,
map: _map,
compact: compact,
separate: separate,
filter: filter,
filterMap: function (ma, f) {
if (isLeft(ma)) {
return ma;
}
var ob = f(ma.right);
return ob._tag === 'None' ? empty : right(ob.value);
},
partition: partition,
partitionMap: function (ma, f) {
if (isLeft(ma)) {
return separated(ma, ma);
}
var e = f(ma.right);
return isLeft(e) ? separated(right(e.left), empty) : separated(empty, right(e.right));
}
};
};
/**
* Builds `Witherable` instance for `Either` given `Monoid` for the left side
*
* @category filtering
* @since 2.0.0
*/
export var getWitherable = function (M) {
var F_ = getFilterable(M);
var C = getCompactable(M);
return {
URI: URI,
_E: undefined,
map: _map,
compact: F_.compact,
separate: F_.separate,
filter: F_.filter,
filterMap: F_.filterMap,
partition: F_.partition,
partitionMap: F_.partitionMap,
traverse: _traverse,
sequence: sequence,
reduce: _reduce,
foldMap: _foldMap,
reduceRight: _reduceRight,
wither: witherDefault(Traversable, C),
wilt: wiltDefault(Traversable, C)
};
};
/**
* The default [`Applicative`](#applicative) instance returns the first error, if you want to
* get all errors you need to provide a way to concatenate them via a `Semigroup`.
*
* @example
* import * as A from 'fp-ts/Apply'
* import * as E from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
* import * as S from 'fp-ts/Semigroup'
* import * as string from 'fp-ts/string'
*
* const parseString = (u: unknown): E.Either<string, string> =>
* typeof u === 'string' ? E.right(u) : E.left('not a string')
*
* const parseNumber = (u: unknown): E.Either<string, number> =>
* typeof u === 'number' ? E.right(u) : E.left('not a number')
*
* interface Person {
* readonly name: string
* readonly age: number
* }
*
* const parsePerson = (
* input: Record<string, unknown>
* ): E.Either<string, Person> =>
* pipe(
* E.Do,
* E.apS('name', parseString(input.name)),
* E.apS('age', parseNumber(input.age))
* )
*
* assert.deepStrictEqual(parsePerson({}), E.left('not a string')) // <= first error
*
* const Applicative = E.getApplicativeValidation(
* pipe(string.Semigroup, S.intercalate(', '))
* )
*
* const apS = A.apS(Applicative)
*
* const parsePersonAll = (
* input: Record<string, unknown>
* ): E.Either<string, Person> =>
* pipe(
* E.Do,
* apS('name', parseString(input.name)),
* apS('age', parseNumber(input.age))
* )
*
* assert.deepStrictEqual(parsePersonAll({}), E.left('not a string, not a number')) // <= all errors
*
* @category error handling
* @since 2.7.0
*/
export var getApplicativeValidation = function (SE) { return ({
URI: URI,
_E: undefined,
map: _map,
ap: function (fab, fa) {
return isLeft(fab)
? isLeft(fa)
? left(SE.concat(fab.left, fa.left))
: fab
: isLeft(fa)
? fa
: right(fab.right(fa.right));
},
of: of
}); };
/**
* The default [`Alt`](#alt) instance returns the last error, if you want to
* get all errors you need to provide a way to concatenate them via a `Semigroup`.
*
* @example
* import * as E from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
* import * as S from 'fp-ts/Semigroup'
* import * as string from 'fp-ts/string'
*
* const parseString = (u: unknown): E.Either<string, string> =>
* typeof u === 'string' ? E.right(u) : E.left('not a string')
*
* const parseNumber = (u: unknown): E.Either<string, number> =>
* typeof u === 'number' ? E.right(u) : E.left('not a number')
*
* const parse = (u: unknown): E.Either<string, string | number> =>
* pipe(
* parseString(u),
* E.alt<string, string | number>(() => parseNumber(u))
* )
*
* assert.deepStrictEqual(parse(true), E.left('not a number')) // <= last error
*
* const Alt = E.getAltValidation(pipe(string.Semigroup, S.intercalate(', ')))
*
* const parseAll = (u: unknown): E.Either<string, string | number> =>
* Alt.alt<string | number>(parseString(u), () => parseNumber(u))
*
* assert.deepStrictEqual(parseAll(true), E.left('not a string, not a number')) // <= all errors
*
* @category error handling
* @since 2.7.0
*/
export var getAltValidation = function (SE) { return ({
URI: URI,
_E: undefined,
map: _map,
alt: function (me, that) {
if (isRight(me)) {
return me;
}
var ea = that();
return isLeft(ea) ? left(SE.concat(me.left, ea.left)) : ea;
}
}); };
/**
* @category mapping
* @since 2.0.0
*/
export var map = function (f) { return function (fa) {
return isLeft(fa) ? fa : right(f(fa.right));
}; };
/**
* @category instances
* @since 2.7.0
*/
export var Functor = {
URI: URI,
map: _map
};
/**
* @category constructors
* @since 2.7.0
*/
export var of = right;
/**
* @category instances
* @since 2.10.0
*/
export var Pointed = {
URI: URI,
of: of
};
/**
* Less strict version of [`ap`](#ap).
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @since 2.8.0
*/
export var apW = function (fa) { return function (fab) {
return isLeft(fab) ? fab : isLeft(fa) ? fa : right(fab.right(fa.right));
}; };
/**
* @since 2.0.0
*/
export var ap = apW;
/**
* @category instances
* @since 2.10.0
*/
export var Apply = {
URI: URI,
map: _map,
ap: _ap
};
/**
* @category instances
* @since 2.7.0
*/
export var Applicative = {
URI: URI,
map: _map,
ap: _ap,
of: of
};
/**
* Less strict version of [`chain`](#chain).
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @example
* import * as E from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
*
* const e1: E.Either<string, number> = E.right(1)
* const e2: E.Either<number, number> = E.right(2)
*
* export const result1 = pipe(
* // @ts-expect-error
* e1,
* E.chain(() => e2)
* )
*
* // merged error types -----v-------------v
* // const result2: E.Either<string | number, number>
* export const result2 = pipe(
* e1, // no error
* E.chainW(() => e2)
* )
*
* @category sequencing
* @since 2.6.0
*/
export var chainW = function (f) {
return function (ma) {
return isLeft(ma) ? ma : f(ma.right);
};
};
/**
* Composes computations in sequence, using the return value of one computation to determine the next computation.
*
* @category sequencing
* @since 2.0.0
*/
export var chain = chainW;
/**
* @category instances
* @since 2.10.0
*/
export var Chain = {
URI: URI,
map: _map,
ap: _ap,
chain: _chain
};
/**
* @category instances
* @since 2.7.0
*/
export var Monad = {
URI: URI,
map: _map,
ap: _ap,
of: of,
chain: _chain
};
/**
* Left-associative fold of a structure.
*
* @example
* import { pipe } from 'fp-ts/function'
* import * as E from 'fp-ts/Either'
*
* const startWith = 'prefix'
* const concat = (a: string, b: string) => `${a}:${b}`
*
* assert.deepStrictEqual(
* pipe(E.right('a'), E.reduce(startWith, concat)),
* 'prefix:a'
* )
*
* assert.deepStrictEqual(
* pipe(E.left('e'), E.reduce(startWith, concat)),
* 'prefix'
* )
*
* @category folding
* @since 2.0.0
*/
export var reduce = function (b, f) { return function (fa) {
return isLeft(fa) ? b : f(b, fa.right);
}; };
/**
* Map each element of the structure to a monoid, and combine the results.
*
* @example
* import { pipe } from 'fp-ts/function'
* import * as E from 'fp-ts/Either'
* import * as S from 'fp-ts/string'
*
* const yell = (a: string) => `${a}!`
*
* assert.deepStrictEqual(
* pipe(E.right('a'), E.foldMap(S.Monoid)(yell)),
* 'a!'
* )
*
* assert.deepStrictEqual(
* pipe(E.left('e'), E.foldMap(S.Monoid)(yell)),
* S.Monoid.empty
* )
*
* @category folding
* @since 2.0.0
*/
export var foldMap = function (M) { return function (f) { return function (fa) {
return isLeft(fa) ? M.empty : f(fa.right);
}; }; };
/**
* Right-associative fold of a structure.
*
* @example
* import { pipe } from 'fp-ts/function'
* import * as E from 'fp-ts/Either'
*
* const startWith = 'postfix'
* const concat = (a: string, b: string) => `${a}:${b}`
*
* assert.deepStrictEqual(
* pipe(E.right('a'), E.reduceRight(startWith, concat)),
* 'a:postfix'
* )
*
* assert.deepStrictEqual(
* pipe(E.left('e'), E.reduceRight(startWith, concat)),
* 'postfix'
* )
*
* @category folding
* @since 2.0.0
*/
export var reduceRight = function (b, f) { return function (fa) {
return isLeft(fa) ? b : f(fa.right, b);
}; };
/**
* @category instances
* @since 2.7.0
*/
export var Foldable = {
URI: URI,
reduce: _reduce,
foldMap: _foldMap,
reduceRight: _reduceRight
};
/**
* Map each element of a structure to an action, evaluate these actions from left to right, and collect the results.
*
* @example
* import { pipe } from 'fp-ts/function'
* import * as RA from 'fp-ts/ReadonlyArray'
* import * as E from 'fp-ts/Either'
* import * as O from 'fp-ts/Option'
*
* assert.deepStrictEqual(
* pipe(E.right(['a']), E.traverse(O.Applicative)(RA.head)),
* O.some(E.right('a'))
* )
*
* assert.deepStrictEqual(
* pipe(E.right([]), E.traverse(O.Applicative)(RA.head)),
* O.none
* )
*
* @category traversing
* @since 2.6.3
*/
export var traverse = function (F) {
return function (f) {
return function (ta) {
return isLeft(ta) ? F.of(left(ta.left)) : F.map(f(ta.right), right);
};
};
};
/**
* Evaluate each monadic action in the structure from left to right, and collect the results.
*
* @example
* import { pipe } from 'fp-ts/function'
* import * as E from 'fp-ts/Either'
* import * as O from 'fp-ts/Option'
*
* assert.deepStrictEqual(
* pipe(E.right(O.some('a')), E.sequence(O.Applicative)),
* O.some(E.right('a'))
* )
*
* assert.deepStrictEqual(
* pipe(E.right(O.none), E.sequence(O.Applicative)),
* O.none
* )
*
* @category traversing
* @since 2.6.3
*/
export var sequence = function (F) {
return function (ma) {
return isLeft(ma) ? F.of(left(ma.left)) : F.map(ma.right, right);
};
};
/**
* @category instances
* @since 2.7.0
*/
export var Traversable = {
URI: URI,
map: _map,
reduce: _reduce,
foldMap: _foldMap,
reduceRight: _reduceRight,
traverse: _traverse,
sequence: sequence
};
/**
* Map a pair of functions over the two type arguments of the bifunctor.
*
* @category mapping
* @since 2.0.0
*/
export var bimap = function (f, g) { return function (fa) {
return isLeft(fa) ? left(f(fa.left)) : right(g(fa.right));
}; };
/**
* Map a function over the first type argument of a bifunctor.
*
* @category error handling
* @since 2.0.0
*/
export var mapLeft = function (f) { return function (fa) {
return isLeft(fa) ? left(f(fa.left)) : fa;
}; };
/**
* @category instances
* @since 2.7.0
*/
export var Bifunctor = {
URI: URI,
bimap: _bimap,
mapLeft: _mapLeft
};
/**
* Less strict version of [`alt`](#alt).
*
* The `W` suffix (short for **W**idening) means that the error and the return types will be merged.
*
* @category error handling
* @since 2.9.0
*/
export var altW = function (that) { return function (fa) {
return isLeft(fa) ? that() : fa;
}; };
/**
* Identifies an associative operation on a type constructor. It is similar to `Semigroup`, except that it applies to
* types of kind `* -> *`.
*
* In case of `Either` returns the left-most non-`Left` value (or the right-most `Left` value if both values are `Left`).
*
* | x | y | pipe(x, alt(() => y) |
* | -------- | -------- | -------------------- |
* | left(a) | left(b) | left(b) |
* | left(a) | right(2) | right(2) |
* | right(1) | left(b) | right(1) |
* | right(1) | right(2) | right(1) |
*
* @example
* import * as E from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(
* pipe(
* E.left('a'),
* E.alt(() => E.left('b'))
* ),
* E.left('b')
* )
* assert.deepStrictEqual(
* pipe(
* E.left('a'),
* E.alt(() => E.right(2))
* ),
* E.right(2)
* )
* assert.deepStrictEqual(
* pipe(
* E.right(1),
* E.alt(() => E.left('b'))
* ),
* E.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* E.right(1),
* E.alt(() => E.right(2))
* ),
* E.right(1)
* )
*
* @category error handling
* @since 2.0.0
*/
export var alt = altW;
/**
* @category instances
* @since 2.7.0
*/
export var Alt = {
URI: URI,
map: _map,
alt: _alt
};
/**
* @since 2.0.0
*/
export var extend = function (f) { return function (wa) {
return isLeft(wa) ? wa : right(f(wa));
}; };
/**
* @category instances
* @since 2.7.0
*/
export var Extend = {
URI: URI,
map: _map,
extend: _extend
};
/**
* @category instances
* @since 2.7.0
*/
export var ChainRec = {
URI: URI,
map: _map,
ap: _ap,
chain: _chain,
chainRec: _chainRec
};
/**
* @since 2.6.3
*/
export var throwError = left;
/**
* @category instances
* @since 2.7.0
*/
export var MonadThrow = {
URI: URI,
map: _map,
ap: _ap,
of: of,
chain: _chain,
throwError: throwError
};
/**
* @category instances
* @since 2.10.0
*/
export var FromEither = {
URI: URI,
fromEither: identity
};
/**
* @example
* import { fromPredicate, left, right } from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(
* pipe(
* 1,
* fromPredicate(
* (n) => n > 0,
* () => 'error'
* )
* ),
* right(1)
* )
* assert.deepStrictEqual(
* pipe(
* -1,
* fromPredicate(
* (n) => n > 0,
* () => 'error'
* )
* ),
* left('error')
* )
*
* @category lifting
* @since 2.0.0
*/
export var fromPredicate = /*#__PURE__*/ fromPredicate_(FromEither);
// -------------------------------------------------------------------------------------
// conversions
// -------------------------------------------------------------------------------------
/**
* @example
* import * as E from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
* import * as O from 'fp-ts/Option'
*
* assert.deepStrictEqual(
* pipe(
* O.some(1),
* E.fromOption(() => 'error')
* ),
* E.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* O.none,
* E.fromOption(() => 'error')
* ),
* E.left('error')
* )
*
* @category conversions
* @since 2.0.0
*/
export var fromOption =
/*#__PURE__*/ fromOption_(FromEither);
// -------------------------------------------------------------------------------------
// refinements
// -------------------------------------------------------------------------------------
/**
* Returns `true` if the either is an instance of `Left`, `false` otherwise.
*
* @category refinements
* @since 2.0.0
*/
export var isLeft = _.isLeft;
/**
* Returns `true` if the either is an instance of `Right`, `false` otherwise.
*
* @category refinements
* @since 2.0.0
*/
export var isRight = _.isRight;
/**
* 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 var matchW = function (onLeft, onRight) {
return function (ma) {
return isLeft(ma) ? onLeft(ma.left) : onRight(ma.right);
};
};
/**
* Alias of [`matchW`](#matchw).
*
* @category pattern matching
* @since 2.10.0
*/
export var foldW = matchW;
/**
* Takes two functions and an `Either` value, if the value is a `Left` the inner value is applied to the first function,
* if the value is a `Right` the inner value is applied to the second function.
*
* @example
* import { match, left, right } from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
*
* function onLeft(errors: Array<string>): string {
* return `Errors: ${errors.join(', ')}`
* }
*
* function onRight(value: number): string {
* return `Ok: ${value}`
* }
*
* assert.strictEqual(
* pipe(
* right(1),
* match(onLeft, onRight)
* ),
* 'Ok: 1'
* )
* assert.strictEqual(
* pipe(
* left(['error 1', 'error 2']),
* match(onLeft, onRight)
* ),
* 'Errors: error 1, error 2'
* )
*
* @category pattern matching
* @since 2.10.0
*/
export var match = matchW;
/**
* Alias of [`match`](#match).
*
* @category pattern matching
* @since 2.0.0
*/
export var fold = match;
/**
* Less strict version of [`getOrElse`](#getorelse).
*
* The `W` suffix (short for **W**idening) means that the handler return type will be merged.
*
* @category error handling
* @since 2.6.0
*/
export var getOrElseW = function (onLeft) {
return function (ma) {
return isLeft(ma) ? onLeft(ma.left) : ma.right;
};
};
/**
* Returns the wrapped value if it's a `Right` or a default value if is a `Left`.
*
* @example
* import { getOrElse, left, right } from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(
* pipe(
* right(1),
* getOrElse(() => 0)
* ),
* 1
* )
* assert.deepStrictEqual(
* pipe(
* left('error'),
* getOrElse(() => 0)
* ),
* 0
* )
*
* @category error handling
* @since 2.0.0
*/
export var getOrElse = getOrElseW;
// -------------------------------------------------------------------------------------
// combinators
// -------------------------------------------------------------------------------------
/**
* @category mapping
* @since 2.10.0
*/
export var flap = /*#__PURE__*/ flap_(Functor);
/**
* Combine two effectful actions, keeping only the result of the first.
*
* @since 2.0.0
*/
export var apFirst = /*#__PURE__*/ apFirst_(Apply);
/**
* Less strict version of [`apFirst`](#apfirst)
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @since 2.12.0
*/
export var apFirstW = apFirst;
/**
* Combine two effectful actions, keeping only the result of the second.
*
* @since 2.0.0
*/
export var apSecond = /*#__PURE__*/ apSecond_(Apply);
/**
* Less strict version of [`apSecond`](#apsecond)
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @since 2.12.0
*/
export var apSecondW = apSecond;
/**
* Composes computations in sequence, using the return value of one computation to determine the next computation and
* keeping only the result of the first.
*
* @category sequencing
* @since 2.0.0
*/
export var chainFirst =
/*#__PURE__*/ chainFirst_(Chain);
/**
* Less strict version of [`chainFirst`](#chainfirst)
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @category sequencing
* @since 2.8.0
*/
export var chainFirstW = chainFirst;
/**
* Less strict version of [`flatten`](#flatten).
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @category sequencing
* @since 2.11.0
*/
export var flattenW =
/*#__PURE__*/ chainW(identity);
/**
* The `flatten` function is the conventional monad join operator. It is used to remove one level of monadic structure, projecting its bound argument into the outer level.
*
* @example
* import * as E from 'fp-ts/Either'
*
* assert.deepStrictEqual(E.flatten(E.right(E.right('a'))), E.right('a'))
* assert.deepStrictEqual(E.flatten(E.right(E.left('e'))), E.left('e'))
* assert.deepStrictEqual(E.flatten(E.left('e')), E.left('e'))
*
* @category sequencing
* @since 2.0.0
*/
export var flatten = flattenW;
/**
* @since 2.0.0
*/
export var duplicate = /*#__PURE__*/ extend(identity);
/**
* @category lifting
* @since 2.10.0
*/
export var fromOptionK =
/*#__PURE__*/ fromOptionK_(FromEither);
/**
* @category sequencing
* @since 2.11.0
*/
export var chainOptionK = /*#__PURE__*/ chainOptionK_(FromEither, Chain);
/**
* @example
* import * as E from 'fp-ts/Either'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(
* pipe(
* E.right(1),
* E.filterOrElse(
* (n) => n > 0,
* () => 'error'
* )
* ),
* E.right(1)
* )
* assert.deepStrictEqual(
* pipe(
* E.right(-1),
* E.filterOrElse(
* (n) => n > 0,
* () => 'error'
* )
* ),
* E.left('error')
* )
* assert.deepStrictEqual(
* pipe(
* E.left('a'),
* E.filterOrElse(
* (n) => n > 0,
* () => 'error'
* )
* ),
* E.left('a')
* )
*
* @category filtering
* @since 2.0.0
*/
export var filterOrElse = /*#__PURE__*/ filterOrElse_(FromEither, Chain);
/**
* Less strict version of [`filterOrElse`](#filterorelse).
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @category filtering
* @since 2.9.0
*/
export var filterOrElseW = filterOrElse;
/**
* Returns a `Right` if is a `Left` (and vice versa).
*
* @since 2.0.0
*/
export var swap = function (ma) { return (isLeft(ma) ? right(ma.left) : left(ma.right)); };
/**
* Less strict version of [`orElse`](#orelse).
*
* The `W` suffix (short for **W**idening) means that the return types will be merged.
*
* @category error handling
* @since 2.10.0
*/
export var orElseW = function (onLeft) {
return function (ma) {
return isLeft(ma) ? onLeft(ma.left) : ma;
};
};
/**
* Useful for recovering from errors.
*
* @category error handling
* @since 2.0.0
*/
export var orElse = orElseW;
/**
* Takes a default and a nullable value, if the value is not nully, turn it into a `Right`, if the value is nully use
* the provided default as a `Left`.
*
* @example
* import { fromNullable, left, right } from 'fp-ts/Either'
*
* const parse = fromNullable('nully')
*
* assert.deepStrictEqual(parse(1), right(1))
* assert.deepStrictEqual(parse(null), left('nully'))
*
* @category conversions
* @since 2.0.0
*/
export var fromNullable = function (e) {
return function (a) {
return a == null ? left(e) : right(a);
};
};
/**
* Constructs a new `Either` from a function that might throw.
*
* See also [`tryCatchK`](#trycatchk).
*
* @example
* import * as E from 'fp-ts/Either'
*
* const unsafeHead = <A>(as: ReadonlyArray<A>): A => {
* if (as.length > 0) {
* return as[0]
* } else {
* throw new Error('empty array')
* }
* }
*
* const head = <A>(as: ReadonlyArray<A>): E.Either<Error, A> =>
* E.tryCatch(() => unsafeHead(as), e => (e instanceof Error ? e : new Error('unknown error')))
*
* assert.deepStrictEqual(head([]), E.left(new Error('empty array')))
* assert.deepStrictEqual(head([1, 2, 3]), E.right(1))
*
* @category interop
* @since 2.0.0
*/
export var tryCatch = function (f, onThrow) {
try {
return right(f());
}
catch (e) {
return left(onThrow(e));
}
};
/**
* Converts a function that may throw to one returning a `Either`.
*
* @category interop
* @since 2.10.0
*/
export var tryCatchK = function (f, onThrow) {
return function () {
var a = [];
for (var _i = 0; _i < arguments.length; _i++) {
a[_i] = arguments[_i];
}
return tryCatch(function () { return f.apply(void 0, a); }, onThrow);
};
};
/**
* @category lifting
* @since 2.9.0
*/
export var fromNullableK = function (e) {
var from = fromNullable(e);
return function (f) { return flow(f, from); };
};
/**
* @category sequencing
* @since 2.9.0
*/
export var chainNullableK = function (e) {
var from = fromNullableK(e);
return function (f) { return chain(from(f)); };
};
/**
* @category conversions
* @since 2.10.0
*/
export var toUnion = /*#__PURE__*/ foldW(identity, identity);
// -------------------------------------------------------------------------------------
// utils
// -------------------------------------------------------------------------------------
/**
* Default value for the `onError` argument of `tryCatch`
*
* @since 2.0.0
*/
export function toError(e) {
return e instanceof Error ? e : new Error(String(e));
}
export function elem(E) {
return function (a, ma) {
if (ma === undefined) {
var elemE_1 = elem(E);
return function (ma) { return elemE_1(a, ma); };
}
return isLeft(ma) ? false : E.equals(a, ma.right);
};
}
/**
* Returns `false` if `Left` or returns the result of the application of the given predicate to the `Right` value.
*
* @example
* import { exists, left, right } from 'fp-ts/Either'
*
* const gt2 = exists((n: number) => n > 2)
*
* assert.strictEqual(gt2(left('a')), false)
* assert.strictEqual(gt2(right(1)), false)
* assert.strictEqual(gt2(right(3)), true)
*
* @since 2.0.0
*/
export var exists = function (predicate) {
return function (ma) {
return isLeft(ma) ? false : predicate(ma.right);
};
};
// -------------------------------------------------------------------------------------
// do notation
// -------------------------------------------------------------------------------------
/**
* @category do notation
* @since 2.9.0
*/
export var Do = /*#__PURE__*/ of(_.emptyRecord);
/**
* @category do notation
* @since 2.8.0
*/
export var bindTo = /*#__PURE__*/ bindTo_(Functor);
var let_ = /*#__PURE__*/ let__(Functor);
export {
/**
* @category do notation
* @since 2.13.0
*/
let_ as let };
/**
* @category do notation
* @since 2.8.0
*/
export var bind = /*#__PURE__*/ bind_(Chain);
/**
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @category do notation
* @since 2.8.0
*/
export var bindW = bind;
/**
* @category do notation
* @since 2.8.0
*/
export var apS = /*#__PURE__*/ apS_(Apply);
/**
* Less strict version of [`apS`](#aps).
*
* The `W` suffix (short for **W**idening) means that the error types will be merged.
*
* @category do notation
* @since 2.8.0
*/
export var apSW = apS;
/**
* @since 2.11.0
*/
export var ApT = /*#__PURE__*/ of(_.emptyReadonlyArray);
// -------------------------------------------------------------------------------------
// array utils
// -------------------------------------------------------------------------------------
/**
* Equivalent to `ReadonlyNonEmptyArray#traverseWithIndex(Applicative)`.
*
* @category traversing
* @since 2.11.0
*/
export var traverseReadonlyNonEmptyArrayWithIndex = function (f) {
return function (as) {
var e = f(0, _.head(as));
if (isLeft(e)) {
return e;
}
var out = [e.right];
for (var i = 1; i < as.length; i++) {
var e_1 = f(i, as[i]);
if (isLeft(e_1)) {
return e_1;
}
out.push(e_1.right);
}
return right(out);
};
};
/**
* Equivalent to `ReadonlyArray#traverseWithIndex(Applicative)`.
*
* @category traversing
* @since 2.11.0
*/
export var traverseReadonlyArrayWithIndex = function (f) {
var g = traverseReadonlyNonEmptyArrayWithIndex(f);
return function (as) { return (_.isNonEmpty(as) ? g(as) : ApT); };
};
/**
* Equivalent to `ReadonlyArray#traverseWithIndex(Applicative)`.
*
* @category traversing
* @since 2.9.0
*/
export var traverseArrayWithIndex = traverseReadonlyArrayWithIndex;
/**
* Equivalent to `ReadonlyArray#traverse(Applicative)`.
*
* @category traversing
* @since 2.9.0
*/
export var traverseArray = function (f) { return traverseReadonlyArrayWithIndex(function (_, a) { return f(a); }); };
/**
* Equivalent to `ReadonlyArray#sequence(Applicative)`.
*
* @category traversing
* @since 2.9.0
*/
export var sequenceArray =
/*#__PURE__*/ traverseArray(identity);
/**
* Use [`parse`](./Json.ts.html#parse) instead.
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export function parseJSON(s, onError) {
return tryCatch(function () { return JSON.parse(s); }, onError);
}
/**
* Use [`stringify`](./Json.ts.html#stringify) instead.
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export var stringifyJSON = function (u, onError) {
return tryCatch(function () {
var s = JSON.stringify(u);
if (typeof s !== 'string') {
throw new Error('Converting unsupported structure to JSON');
}
return s;
}, onError);
};
/**
* This instance is deprecated, use small, specific instances instead.
* For example if a function needs a `Functor` instance, pass `E.Functor` instead of `E.either`
* (where `E` is from `import E from 'fp-ts/Either'`)
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export var either = {
URI: URI,
map: _map,
of: of,
ap: _ap,
chain: _chain,
reduce: _reduce,
foldMap: _foldMap,
reduceRight: _reduceRight,
traverse: _traverse,
sequence: sequence,
bimap: _bimap,
mapLeft: _mapLeft,
alt: _alt,
extend: _extend,
chainRec: _chainRec,
throwError: throwError
};
/**
* Use [`getApplySemigroup`](./Apply.ts.html#getapplysemigroup) instead.
*
* Semigroup returning the left-most `Left` value. If both operands are `Right`s then the inner values
* are concatenated using the provided `Semigroup`
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export var getApplySemigroup =
/*#__PURE__*/ getApplySemigroup_(Apply);
/**
* Use [`getApplicativeMonoid`](./Applicative.ts.html#getapplicativemonoid) instead.
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export var getApplyMonoid =
/*#__PURE__*/ getApplicativeMonoid(Applicative);
/**
* Use [`getApplySemigroup`](./Apply.ts.html#getapplysemigroup) instead.
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export var getValidationSemigroup = function (SE, SA) {
return getApplySemigroup_(getApplicativeValidation(SE))(SA);
};
/**
* Use [`getApplicativeMonoid`](./Applicative.ts.html#getapplicativemonoid) instead.
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export var getValidationMonoid = function (SE, MA) {
return getApplicativeMonoid(getApplicativeValidation(SE))(MA);
};
/**
* Use [`getApplicativeValidation`](#getapplicativevalidation) and [`getAltValidation`](#getaltvalidation) instead.
*
* @category zone of death
* @since 2.0.0
* @deprecated
*/
export function getValidation(SE) {
var ap = getApplicativeValidation(SE).ap;
var alt = getAltValidation(SE).alt;
return {
URI: URI,
_E: undefined,
map: _map,
of: of,
chain: _chain,
bimap: _bimap,
mapLeft: _mapLeft,
reduce: _reduce,
foldMap: _foldMap,
reduceRight: _reduceRight,
extend: _extend,
traverse: _traverse,
sequence: sequence,
chainRec: _chainRec,
throwError: throwError,
ap: ap,
alt: alt
};
}