"use strict"; var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) { if (k2 === undefined) k2 = k; var desc = Object.getOwnPropertyDescriptor(m, k); if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) { desc = { enumerable: true, get: function() { return m[k]; } }; } Object.defineProperty(o, k2, desc); }) : (function(o, m, k, k2) { if (k2 === undefined) k2 = k; o[k2] = m[k]; })); var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) { Object.defineProperty(o, "default", { enumerable: true, value: v }); }) : function(o, v) { o["default"] = v; }); var __importStar = (this && this.__importStar) || function (mod) { if (mod && mod.__esModule) return mod; var result = {}; if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k); __setModuleDefault(result, mod); return result; }; Object.defineProperty(exports, "__esModule", { value: true }); exports.traverseArray = exports.traverseArrayWithIndex = exports.traverseReadonlyArrayWithIndex = exports.traverseReadonlyNonEmptyArrayWithIndex = exports.ApT = exports.apSW = exports.apS = exports.Do = exports.bindW = exports.bind = exports.let = exports.bindTo = exports.Choice = exports.Strong = exports.Category = exports.Profunctor = exports.chainFirstW = exports.chainFirst = exports.Monad = exports.Chain = exports.Applicative = exports.apSecondW = exports.apSecond = exports.apFirstW = exports.apFirst = exports.Apply = exports.Pointed = exports.flap = exports.Functor = exports.URI = exports.right = exports.left = exports.second = exports.first = exports.id = exports.promap = exports.compose = exports.flatten = exports.flattenW = exports.chain = exports.chainW = exports.of = exports.ap = exports.apW = exports.map = exports.asksReader = exports.asksReaderW = exports.local = exports.asks = exports.ask = void 0; exports.getMonoid = exports.getSemigroup = exports.reader = exports.sequenceArray = void 0; /** * The `Reader` monad (also called the Environment monad). Represents a computation, which can read values from a shared environment, * pass values from function to function, and execute sub-computations in a modified environment. * Using `Reader` monad for such computations is often clearer and easier than using the `State` monad. * * In this example the `Reader` monad provides access to variable bindings. `Bindings` are a map of `number` variables. * The variable count contains number of variables in the bindings. You can see how to run a `Reader` monad and retrieve * data from it, how to access the `Reader` data with `ask` and `asks`. * * @example * import { pipe } from 'fp-ts/function' * import * as O from 'fp-ts/Option' * import * as R from 'fp-ts/Reader' * import * as RR from 'fp-ts/ReadonlyRecord' * * interface Bindings extends RR.ReadonlyRecord {} * * // The Reader monad, which implements this complicated check. * const isCountCorrect: R.Reader = pipe( * R.Do, * R.bind('count', () => R.asks(lookupVar('count'))), * R.bind('bindings', () => R.ask()), * R.map(({ count, bindings }) => count === RR.size(bindings)) * ) * * // The selector function to use with 'asks'. * // Returns value of the variable with specified name. * const lookupVar = (name: string) => (bindings: Bindings): number => * pipe( * bindings, * RR.lookup(name), * O.getOrElse(() => 0) * ) * * const sampleBindings: Bindings = { count: 3, a: 1, b: 2 } * * assert.deepStrictEqual(isCountCorrect(sampleBindings), true) * * @since 2.0.0 */ var Applicative_1 = require("./Applicative"); var Apply_1 = require("./Apply"); var Chain_1 = require("./Chain"); var E = __importStar(require("./Either")); var function_1 = require("./function"); var Functor_1 = require("./Functor"); var _ = __importStar(require("./internal")); // ------------------------------------------------------------------------------------- // constructors // ------------------------------------------------------------------------------------- /** * Reads the current context * * @category constructors * @since 2.0.0 */ var ask = function () { return function_1.identity; }; exports.ask = ask; /** * Projects a value from the global context in a Reader * * @category constructors * @since 2.0.0 */ exports.asks = function_1.identity; // ------------------------------------------------------------------------------------- // combinators // ------------------------------------------------------------------------------------- /** * Changes the value of the local context during the execution of the action `ma` (similar to `Contravariant`'s * `contramap`). * * @example * import { pipe } from 'fp-ts/function' * import * as R from 'fp-ts/Reader' * import * as string from 'fp-ts/string' * * const calculateContentLen: R.Reader = pipe( * R.Do, * R.bind('content', () => R.ask()), * R.map(({ content }) => string.size(content)) * ) * * // Calls calculateContentLen after adding a prefix to the Reader content. * const calculateModifiedContentLen: R.Reader = pipe( * calculateContentLen, * R.local((s) => 'Prefix ' + s) * ) * * const s = '12345' * * assert.deepStrictEqual( * "Modified 's' length: " + calculateModifiedContentLen(s) + '\n' + "Original 's' length: " + calculateContentLen(s), * "Modified 's' length: 12\nOriginal 's' length: 5" * ) * * @since 2.0.0 */ var local = function (f) { return function (ma) { return function (r2) { return ma(f(r2)); }; }; }; exports.local = local; /** * Less strict version of [`asksReader`](#asksreader). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @category constructors * @since 2.11.0 */ var asksReaderW = function (f) { return function (r) { return f(r)(r); }; }; exports.asksReaderW = asksReaderW; /** * Effectfully accesses the environment. * * @category constructors * @since 2.11.0 */ exports.asksReader = exports.asksReaderW; /* istanbul ignore next */ var _map = function (fa, f) { return (0, function_1.pipe)(fa, (0, exports.map)(f)); }; /* istanbul ignore next */ var _ap = function (fab, fa) { return (0, function_1.pipe)(fab, (0, exports.ap)(fa)); }; /* istanbul ignore next */ var _chain = function (ma, f) { return (0, function_1.pipe)(ma, (0, exports.chain)(f)); }; var _compose = function (bc, ab) { return (0, function_1.pipe)(bc, (0, exports.compose)(ab)); }; var _promap = function (fea, f, g) { return (0, function_1.pipe)(fea, (0, exports.promap)(f, g)); }; /** * `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 */ var map = function (f) { return function (fa) { return function (r) { return f(fa(r)); }; }; }; exports.map = map; /** * Less strict version of [`ap`](#ap). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @since 2.8.0 */ var apW = function (fa) { return function (fab) { return function (r) { return fab(r)(fa(r)); }; }; }; exports.apW = apW; /** * @since 2.0.0 */ exports.ap = exports.apW; /** * @category constructors * @since 2.0.0 */ exports.of = function_1.constant; /** * Less strict version of [`chain`](#chain). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @category sequencing * @since 2.6.0 */ var chainW = function (f) { return function (fa) { return function (r) { return f(fa(r))(r); }; }; }; exports.chainW = chainW; /** * Composes computations in sequence, using the return value of one computation to determine the next computation. * * @category sequencing * @since 2.0.0 */ exports.chain = exports.chainW; /** * Less strict version of [`flatten`](#flatten). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @category sequencing * @since 2.11.0 */ exports.flattenW = /*#__PURE__*/ (0, exports.chainW)(function_1.identity); /** * @category sequencing * @since 2.0.0 */ exports.flatten = exports.flattenW; /** * @since 2.0.0 */ var compose = function (ab) { return function (bc) { return (0, function_1.flow)(ab, bc); }; }; exports.compose = compose; /** * @since 2.0.0 */ var promap = function (f, g) { return function (fea) { return function (a) { return g(fea(f(a))); }; }; }; exports.promap = promap; /** * @category constructors * @since 2.0.0 */ var id = function () { return function_1.identity; }; exports.id = id; /** * @since 2.10.0 */ var first = function (pab) { return function (_a) { var a = _a[0], c = _a[1]; return [pab(a), c]; }; }; exports.first = first; /** * @since 2.10.0 */ var second = function (pbc) { return function (_a) { var a = _a[0], b = _a[1]; return [a, pbc(b)]; }; }; exports.second = second; /** * @since 2.10.0 */ var left = function (pab) { return E.fold(function (a) { return _.left(pab(a)); }, E.right); }; exports.left = left; /** * @since 2.10.0 */ var right = function (pbc) { return E.fold(E.left, function (b) { return _.right(pbc(b)); }); }; exports.right = right; /** * @category type lambdas * @since 2.0.0 */ exports.URI = 'Reader'; /** * @category instances * @since 2.7.0 */ exports.Functor = { URI: exports.URI, map: _map }; /** * @category mapping * @since 2.10.0 */ exports.flap = (0, Functor_1.flap)(exports.Functor); /** * @category instances * @since 2.10.0 */ exports.Pointed = { URI: exports.URI, of: exports.of }; /** * @category instances * @since 2.10.0 */ exports.Apply = { URI: exports.URI, map: _map, ap: _ap }; /** * Combine two effectful actions, keeping only the result of the first. * * @since 2.0.0 */ exports.apFirst = (0, Apply_1.apFirst)(exports.Apply); /** * Less strict version of [`apFirst`](#apfirst). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @since 2.12.0 */ exports.apFirstW = exports.apFirst; /** * Combine two effectful actions, keeping only the result of the second. * * @since 2.0.0 */ exports.apSecond = (0, Apply_1.apSecond)(exports.Apply); /** * Less strict version of [`apSecond`](#apsecond). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @since 2.12.0 */ exports.apSecondW = exports.apSecond; /** * @category instances * @since 2.7.0 */ exports.Applicative = { URI: exports.URI, map: _map, ap: _ap, of: exports.of }; /** * @category instances * @since 2.10.0 */ exports.Chain = { URI: exports.URI, map: _map, ap: _ap, chain: _chain }; /** * @category instances * @since 2.7.0 */ exports.Monad = { URI: exports.URI, map: _map, of: exports.of, ap: _ap, 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 */ exports.chainFirst = /*#__PURE__*/ (0, Chain_1.chainFirst)(exports.Chain); /** * Less strict version of [`chainFirst`](#chainfirst). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @category sequencing * @since 2.11.0 */ exports.chainFirstW = exports.chainFirst; /** * @category instances * @since 2.7.0 */ exports.Profunctor = { URI: exports.URI, map: _map, promap: _promap }; /** * @category instances * @since 2.7.0 */ exports.Category = { URI: exports.URI, compose: _compose, id: exports.id }; /** * @category instances * @since 2.8.3 */ exports.Strong = { URI: exports.URI, map: _map, promap: _promap, first: exports.first, second: exports.second }; /** * @category instances * @since 2.8.3 */ exports.Choice = { URI: exports.URI, map: _map, promap: _promap, left: exports.left, right: exports.right }; // ------------------------------------------------------------------------------------- // do notation // ------------------------------------------------------------------------------------- /** * @category do notation * @since 2.8.0 */ exports.bindTo = (0, Functor_1.bindTo)(exports.Functor); var let_ = /*#__PURE__*/ (0, Functor_1.let)(exports.Functor); exports.let = let_; /** * @category do notation * @since 2.8.0 */ exports.bind = (0, Chain_1.bind)(exports.Chain); /** * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @category do notation * @since 2.8.0 */ exports.bindW = exports.bind; /** * @category do notation * @since 2.9.0 */ exports.Do = (0, exports.of)(_.emptyRecord); /** * @category do notation * @since 2.8.0 */ exports.apS = (0, Apply_1.apS)(exports.Apply); /** * Less strict version of [`apS`](#aps). * * The `W` suffix (short for **W**idening) means that the environment types will be merged. * * @category do notation * @since 2.8.0 */ exports.apSW = exports.apS; /** * @since 2.11.0 */ exports.ApT = (0, exports.of)(_.emptyReadonlyArray); // ------------------------------------------------------------------------------------- // array utils // ------------------------------------------------------------------------------------- /** * Equivalent to `ReadonlyNonEmptyArray#traverseWithIndex(Applicative)`. * * @category traversing * @since 2.11.0 */ var traverseReadonlyNonEmptyArrayWithIndex = function (f) { return function (as) { return function (r) { var out = [f(0, _.head(as))(r)]; for (var i = 1; i < as.length; i++) { out.push(f(i, as[i])(r)); } return out; }; }; }; exports.traverseReadonlyNonEmptyArrayWithIndex = traverseReadonlyNonEmptyArrayWithIndex; /** * Equivalent to `ReadonlyArray#traverseWithIndex(Applicative)`. * * @category traversing * @since 2.11.0 */ var traverseReadonlyArrayWithIndex = function (f) { var g = (0, exports.traverseReadonlyNonEmptyArrayWithIndex)(f); return function (as) { return (_.isNonEmpty(as) ? g(as) : exports.ApT); }; }; exports.traverseReadonlyArrayWithIndex = traverseReadonlyArrayWithIndex; /** * Equivalent to `ReadonlyArray#traverseWithIndex(Applicative)`. * * @category traversing * @since 2.9.0 */ exports.traverseArrayWithIndex = exports.traverseReadonlyArrayWithIndex; /** * Equivalent to `ReadonlyArray#traverse(Applicative)`. * * @category traversing * @since 2.9.0 */ var traverseArray = function (f) { return (0, exports.traverseReadonlyArrayWithIndex)(function (_, a) { return f(a); }); }; exports.traverseArray = traverseArray; /** * Equivalent to `ReadonlyArray#sequence(Applicative)`. * * @category traversing * @since 2.9.0 */ exports.sequenceArray = /*#__PURE__*/ (0, exports.traverseArray)(function_1.identity); // ------------------------------------------------------------------------------------- // deprecated // ------------------------------------------------------------------------------------- /** * This instance is deprecated, use small, specific instances instead. * For example if a function needs a `Functor` instance, pass `R.Functor` instead of `R.reader` * (where `R` is from `import R from 'fp-ts/Reader'`) * * @category zone of death * @since 2.0.0 * @deprecated */ exports.reader = { URI: exports.URI, map: _map, of: exports.of, ap: _ap, chain: _chain, promap: _promap, compose: _compose, id: exports.id, first: exports.first, second: exports.second, left: exports.left, right: exports.right }; /** * Use [`getApplySemigroup`](./Apply.ts.html#getapplysemigroup) instead. * * @category zone of death * @since 2.0.0 * @deprecated */ exports.getSemigroup = (0, Apply_1.getApplySemigroup)(exports.Apply); /** * Use [`getApplicativeMonoid`](./Applicative.ts.html#getapplicativemonoid) instead. * * @category zone of death * @since 2.0.0 * @deprecated */ exports.getMonoid = (0, Applicative_1.getApplicativeMonoid)(exports.Applicative);