/** * ```ts * interface IO { * (): A * } * ``` * * `IO` represents a non-deterministic synchronous computation that can cause side effects, yields a value of * type `A` and **never fails**. * * If you want to represent a synchronous computation that may fail, please see `IOEither`. * If you want to represent a synchronous computation that may yield nothing, please see `IOOption`. * * @since 2.0.0 */ import { getApplicativeMonoid } from './Applicative'; import { apFirst as apFirst_, apS as apS_, apSecond as apSecond_, getApplySemigroup } from './Apply'; import { bind as bind_, chainFirst as chainFirst_ } from './Chain'; import { constant, identity } from './function'; import { let as let__, bindTo as bindTo_, flap as flap_ } from './Functor'; import * as _ from './internal'; var _map = function (ma, f) { return function () { return f(ma()); }; }; var _ap = function (mab, ma) { return function () { return mab()(ma()); }; }; var _chain = function (ma, f) { return function () { return f(ma())(); }; }; var _chainRec = function (a, f) { return function () { var e = f(a)(); while (e._tag === 'Left') { e = f(e.left)(); } return e.right; }; }; /** * `map` can be used to turn functions `(a: A) => B` into functions `(fa: F) => F` whose argument and return types * use the type constructor `F` to represent some computational context. * * @category mapping * @since 2.0.0 */ export var map = function (f) { return function (fa) { return _map(fa, f); }; }; /** * @since 2.0.0 */ export var ap = function (fa) { return function (fab) { return _ap(fab, fa); }; }; /** * @category constructors * @since 2.0.0 */ export var of = constant; /** * 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 = function (f) { return function (ma) { return _chain(ma, f); }; }; /** * @category sequencing * @since 2.0.0 */ export var flatten = /*#__PURE__*/ chain(identity); /** * @category type lambdas * @since 2.0.0 */ export var URI = 'IO'; /** * @category instances * @since 2.7.0 */ export var Functor = { URI: URI, map: _map }; /** * @category mapping * @since 2.10.0 */ export var flap = /*#__PURE__*/ flap_(Functor); /** * @category instances * @since 2.10.0 */ export var Pointed = { URI: URI, of: of }; /** * @category instances * @since 2.10.0 */ export var Apply = { URI: URI, map: _map, ap: _ap }; /** * Combine two effectful actions, keeping only the result of the first. * * @since 2.0.0 */ export var apFirst = /*#__PURE__*/ apFirst_(Apply); /** * Combine two effectful actions, keeping only the result of the second. * * @since 2.0.0 */ export var apSecond = /*#__PURE__*/ apSecond_(Apply); /** * @category instances * @since 2.7.0 */ export var Applicative = { URI: URI, map: _map, ap: _ap, of: of }; /** * @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 }; /** * 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); /** * @category zone of death * @since 2.7.0 * @deprecated */ export var fromIO = identity; /** * @category instances * @since 2.7.0 */ export var MonadIO = { URI: URI, map: _map, ap: _ap, of: of, chain: _chain, fromIO: fromIO }; /** * @category instances * @since 2.7.0 */ export var ChainRec = { URI: URI, map: _map, ap: _ap, chain: _chain, chainRec: _chainRec }; /** * @category instances * @since 2.10.0 */ export var FromIO = { URI: URI, fromIO: identity }; // ------------------------------------------------------------------------------------- // 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); /** * @category do notation * @since 2.8.0 */ export var apS = /*#__PURE__*/ apS_(Apply); /** * @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) { return function () { var out = [f(0, _.head(as))()]; for (var i = 1; i < as.length; i++) { out.push(f(i, as[i])()); } return 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); // ------------------------------------------------------------------------------------- // deprecated // ------------------------------------------------------------------------------------- /** * This instance is deprecated, use small, specific instances instead. * For example if a function needs a `Functor` instance, pass `IO.Functor` instead of `IO.io` * (where `IO` is from `import IO from 'fp-ts/IO'`) * * @category zone of death * @since 2.0.0 * @deprecated */ export var io = { URI: URI, map: _map, of: of, ap: _ap, chain: _chain, fromIO: fromIO, chainRec: _chainRec }; /** * Use [`getApplySemigroup`](./Apply.ts.html#getapplysemigroup) instead. * * @category zone of death * @since 2.0.0 * @deprecated */ export var getSemigroup = /*#__PURE__*/ getApplySemigroup(Apply); /** * Use [`getApplicativeMonoid`](./Applicative.ts.html#getapplicativemonoid) instead. * * @category zone of death * @since 2.0.0 * @deprecated */ export var getMonoid = /*#__PURE__*/ getApplicativeMonoid(Applicative);