funfix-core/dist/disjunctions.js

/*!
 * Copyright (c) 2017-2018 by The Funfix Project Developers.
 * Some rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import * as std from "./std";
import { NoSuchElementError } from "./errors";
import { fantasyLandRegister } from "./internals";
/**
 * Represents a value of one of two possible types (a disjoint union).
 *
 * A common use of Either is as an alternative to [[Option]] for dealing
 * with possible missing values. In this usage [[Option.none]] is replaced
 * with [[Either.left]] which can contain useful information and
 * [[Option.some]] is replaced with [[Either.right]].
 *
 * Convention dictates that `left` is used for failure and `right` is used
 * for success. Note that this `Either` type is right-biased, meaning that
 * operations such as `map`, `flatMap` and `filter` work on the `right` value
 * and if you want to work on the `left` value, then you need to do a `swap`.
 *
 * For example, you could use `Either<String, Int>` to detect whether an
 * input is a string or an number:
 *
 * ```typescript
 * function tryParseInt(str: string): Either<string, number> {
 *   const i = parseInt(value)
 *   return isNaN(i) ? Left(str) : Right(i)
 * }
 *
 * const result = tryParseInt("not an int")
 * if (result.isRight()) {
 *   console.log(`Increment: ${result.get}`)
 * } else {
 *   console.log(`ERROR: could not parse ${result.swap.get}`)
 * }
 * ```
 *
 * @final
 */
export class Either {
    constructor(value, tag) {
        this._isRight = tag === "right";
        this.value = value;
    }
    /**
     * Returns `true` if this is a `left`, `false` otherwise.
     *
     * ```typescript
     * Left("hello").isLeft() // true
     * Right(10).isLeft() // false
     * ```
     */
    isLeft() { return !this._isRight; }
    /**
     * Returns `true` if this is a `right`, `false` otherwise.
     *
     * ```typescript
     * Left("hello").isRight() // false
     * Right(10).isRight() // true
     * ```
     */
    isRight() { return this._isRight; }
    /**
     * Returns true if this is a Right and its value is equal to `elem`
     * (as determined by the `equals` protocol), returns `false` otherwise.
     *
     * ```typescript
     * // True
     * Right("something").contains("something")
     *
     * // False because the values are different
     * Right("something").contains("anything") // false
     *
     * // False because the source is a `left`
     * Left("something").contains("something") // false
     * ```
     */
    contains(elem) {
        return this._isRight && std.is(this.value, elem);
    }
    /**
     * Returns `false` if the source is a `left`, or returns the result
     * of the application of the given predicate to the `right` value.
     *
     * ```typescript
     * // True, because it is a right and predicate holds
     * Right(20).exists(n => n > 10)
     *
     * // False, because the predicate returns false
     * Right(10).exists(n => n % 2 != 0)
     *
     * // False, because it is a left
     * Left(10).exists(n => n == 10)
     * ```
     */
    exists(p) {
        return this._isRight && p(this.value);
    }
    /**
     * Filters `right` values with the given predicate, returning
     * the value generated by `zero` in case the source is a `right`
     * value and the predicate doesn't hold.
     *
     * Possible outcomes:
     *
     *  - Returns the existing value of `right` if this is a `right` value and the
     *    given predicate `p` holds for it
     *  - Returns `Left(zero())` if this is a `right` value
     *    and the given predicate `p` does not hold
     *  - Returns the current "left" value, if the source is a `Left`
     *
     * ```typescript
     * Right(12).filterOrElse(x => x > 10, () => -1) // Right(12)
     * Right(7).filterOrElse(x => x > 10, () => -1)  // Left(-1)
     * Left(7).filterOrElse(x => false, () => -1)    // Left(7)
     * ```
     */
    filterOrElse(p, zero) {
        return this._isRight
            ? (p(this.value) ? this : Left(zero()))
            : this;
    }
    /**
     * Binds the given function across `right` values.
     *
     * This operation is the monadic "bind" operation.
     * It can be used to *chain* multiple `Either` references.
     */
    flatMap(f) {
        return this._isRight ? f(this.value) : this;
    }
    /** Alias for [[flatMap]]. */
    chain(f) {
        return this.flatMap(f);
    }
    /**
     * `Applicative` apply operator.
     *
     * Resembles {@link map}, but the passed mapping function is
     * lifted in the `Either` context.
     */
    ap(ff) {
        return ff.flatMap(f => this.map(f));
    }
    /**
     * Applies the `left` function to [[Left]] values, and the
     * `right` function to [[Right]] values and returns the result.
     *
     * ```typescript
     * const maybeNum: Either<string, number> =
     *   tryParseInt("not a number")
     *
     * const result: string =
     *   maybeNum.fold(
     *     str => `Could not parse string: ${str}`,
     *     num => `Success: ${num}`
     *   )
     * ```
     */
    fold(left, right) {
        return this._isRight ? right(this.value) : left(this.value);
    }
    /**
     * Returns true if the source is a `left` or returns
     * the result of the application of the given predicate to the
     * `right` value.
     *
     * ```typescript
     * // True, because it is a `left`
     * Left("hello").forAll(x => x > 10)
     *
     * // True, because the predicate holds
     * Right(20).forAll(x => x > 10)
     *
     * // False, it's a right and the predicate doesn't hold
     * Right(7).forAll(x => x > 10)
     * ```
     */
    forAll(p) {
        return !this._isRight || p(this.value);
    }
    /**
     * Returns the `Right` value, if the source has one,
     * otherwise throws an exception.
     *
     * WARNING!
     *
     * This function is partial, the `Either` must be a `Right`, otherwise
     * a runtime exception will get thrown. Use with care.
     *
     * @throws [[NoSuchElementError]] in case the the `Either` is a `Left`
     */
    get() {
        if (this._isRight)
            return this.value;
        throw new NoSuchElementError("left.get()");
    }
    /**
     * Returns the value from this `right` or the given `fallback`
     * value if this is a `left`.
     *
     * ```typescript
     * Right(10).getOrElse(27) // 10
     * Left(10).getOrElse(27)  // 27
     * ```
     */
    getOrElse(fallback) {
        return this._isRight ? this.value : fallback;
    }
    /**
     * Returns the value from this `right` or a value generated
     * by the given `thunk` if this is a `left`.
     *
     * ```typescript
     * Right(10).getOrElseL(() => 27) // 10
     * Left(10).getOrElseL(() => 27)  // 27
     * ```
     */
    getOrElseL(thunk) {
        return this._isRight ? this.value : thunk();
    }
    /**
     * Transform the source if it is a `right` with the given
     * mapping function.
     *
     * ```typescript
     * Right(10).map(x => x + 17) // right(27)
     * Left(10).map(x => x + 17)  // left(10)
     * ```
     */
    map(f) {
        return this._isRight
            ? Right(f(this.value))
            : this;
    }
    /**
     * Executes the given side-effecting function if the
     * source is a `right` value.
     *
     * ```typescript
     * Right(12).forAll(console.log) // prints 12
     * Left(10).forAll(console.log)  // silent
     * ```
     */
    forEach(cb) {
        if (this._isRight)
            cb(this.value);
    }
    /**
     * If this is a `left`, then return the left value as a `right`
     * or vice versa.
     *
     * ```typescript
     * Right(10).swap() // left(10)
     * Left(20).swap()  // right(20)
     * ```
     */
    swap() {
        return this._isRight
            ? Left(this.value)
            : Right(this.value);
    }
    /**
     * Returns an `Option.some(right)` if the source is a `right` value,
     * or `Option.none` in case the source is a `left` value.
     */
    toOption() {
        return this._isRight ? Some(this.value) : None;
    }
    /**
     * Implements {@link IEquals.equals}.
     *
     * @param that is the right hand side of the equality check
     */
    equals(that) {
        // tslint:disable-next-line:strict-type-predicates
        if (that == null)
            return false;
        return this._isRight === that._isRight && std.is(this.value, that.value);
    }
    /** Implements {@link IEquals.hashCode}. */
    hashCode() {
        return this._isRight
            ? std.hashCode(this.value) << 2
            : std.hashCode(this.value) << 3;
    }
    /**
     * Builds a pure `Either` value.
     *
     * This operation is the pure `Applicative` operation for lifting
     * a value in the `Either` context.
     */
    static pure(value) {
        return new TRight(value);
    }
    /**
     * Builds a left value, equivalent with {@link Left}.
     */
    static left(value) {
        return Left(value);
    }
    /**
     * Builds a right value, equivalent with {@link Right}.
     */
    static right(value) {
        return Right(value);
    }
    /**
     * Maps 2 `Either` values by the mapping function, returning a new
     * `Either` reference that is a `Right` only if both `Either` values are
     * `Right` values, otherwise it returns the first `Left` value noticed.
     *
     * ```typescript
     * // Yields Right(3)
     * Try.map2(Right(1), Right(2),
     *   (a, b) => a + b
     * )
     *
     * // Yields Left, because the second arg is a Left
     * Try.map2(Right(1), Left("error"),
     *   (a, b) => a + b
     * )
     * ```
     *
     * This operation is the `Applicative.map2`.
     */
    static map2(fa1, fa2, f) {
        if (fa1.isLeft())
            return fa1;
        if (fa2.isLeft())
            return fa2;
        return Right(f(fa1.value, fa2.value));
    }
    /**
     * Maps 3 `Either` values by the mapping function, returning a new
     * `Either` reference that is a `Right` only if all 3 `Either` values are
     * `Right` values, otherwise it returns the first `Left` value noticed.
     *
     * ```typescript
     * // Yields Right(6)
     * Try.map3(Right(1), Right(2), Right(3),
     *   (a, b, c) => a + b + c
     * )
     *
     * // Yields Left, because the second arg is a Left
     * Try.map3(Right(1), Left("error"), Right(3),
     *   (a, b, c) => a + b + c
     * )
     * ```
     */
    static map3(fa1, fa2, fa3, f) {
        if (fa1.isLeft())
            return fa1;
        if (fa2.isLeft())
            return fa2;
        if (fa3.isLeft())
            return fa3;
        return Right(f(fa1.value, fa2.value, fa3.value));
    }
    /**
     * Maps 4 `Either` values by the mapping function, returning a new
     * `Either` reference that is a `Right` only if all 4 `Either` values are
     * `Right` values, otherwise it returns the first `Left` value noticed.
     *
     * ```typescript
     * // Yields Right(10)
     * Try.map4(Right(1), Right(2), Right(3), Right(4),
     *   (a, b, c, d) => a + b + c + d
     * )
     *
     * // Yields Left, because the second arg is a Left
     * Try.map4(Right(1), Left("error"), Right(3), Right(4),
     *   (a, b, c, d) => a + b + c + d
     * )
     * ```
     */
    static map4(fa1, fa2, fa3, fa4, f) {
        if (fa1.isLeft())
            return fa1;
        if (fa2.isLeft())
            return fa2;
        if (fa3.isLeft())
            return fa3;
        if (fa4.isLeft())
            return fa4;
        return Right(f(fa1.value, fa2.value, fa3.value, fa4.value));
    }
    /**
     * Maps 5 `Either` values by the mapping function, returning a new
     * `Either` reference that is a `Right` only if all 5 `Either` values are
     * `Right` values, otherwise it returns the first `Left` value noticed.
     *
     * ```typescript
     * // Yields Right(15)
     * Try.map5(Right(1), Right(2), Right(3), Right(4), Right(5),
     *   (a, b, c, d, e) => a + b + c + d + e
     * )
     *
     * // Yields Left, because the second arg is a Left
     * Try.map5(Right(1), Left("error"), Right(3), Right(4), Right(5),
     *   (a, b, c, d, e) => a + b + c + d + e
     * )
     * ```
     */
    static map5(fa1, fa2, fa3, fa4, fa5, f) {
        if (fa1.isLeft())
            return fa1;
        if (fa2.isLeft())
            return fa2;
        if (fa3.isLeft())
            return fa3;
        if (fa4.isLeft())
            return fa4;
        if (fa5.isLeft())
            return fa5;
        return Right(f(fa1.value, fa2.value, fa3.value, fa4.value, fa5.value));
    }
    /**
     * Maps 6 `Either` values by the mapping function, returning a new
     * `Either` reference that is a `Right` only if all 6 `Either` values are
     * `Right` values, otherwise it returns the first `Left` value noticed.
     *
     * ```typescript
     * // Yields Right(21)
     * Try.map5(Right(1), Right(2), Right(3), Right(4), Right(5), Right(6),
     *   (a, b, c, d, e, f) => a + b + c + d + e + f
     * )
     *
     * // Yields Left, because the second arg is a Left
     * Try.map5(Right(1), Left("error"), Right(3), Right(4), Right(5), Right(6),
     *   (a, b, c, d, e, f) => a + b + c + d + e + f
     * )
     * ```
     */
    static map6(fa1, fa2, fa3, fa4, fa5, fa6, f) {
        if (fa1.isLeft())
            return fa1;
        if (fa2.isLeft())
            return fa2;
        if (fa3.isLeft())
            return fa3;
        if (fa4.isLeft())
            return fa4;
        if (fa5.isLeft())
            return fa5;
        if (fa6.isLeft())
            return fa6;
        return Right(f(fa1.value, fa2.value, fa3.value, fa4.value, fa5.value, fa6.value));
    }
    /**
     * Keeps calling `f` until a `Right(b)` is returned.
     *
     * Based on Phil Freeman's
     * [Stack Safety for Free]{@link http://functorial.com/stack-safety-for-free/index.pdf}.
     *
     * Described in `FlatMap.tailRecM`.
     */
    static tailRecM(a, f) {
        let cursor = a;
        while (true) {
            const result = f(cursor);
            if (!result.isRight())
                return result;
            const some = result.value;
            if (some.isRight())
                return Right(some.value);
            cursor = some.value;
        }
    }
}
/**
 * Result of the [[Left]] data constructor, representing
 * "left" values in the [[Either]] disjunction.
 *
 * @final
 */
export class TLeft extends Either {
    constructor(value) { super(value, "left"); }
}
/**
 * The `Left` data constructor represents the left side of the
 * [[Either]] disjoint union, as opposed to the [[Right]] side.
 */
export function Left(value) {
    return new TLeft(value);
}
/**
 * Result of the [[Right]] data constructor, representing
 * "right" values in the [[Either]] disjunction.
 *
 * @final
 */
export class TRight extends Either {
    constructor(value) { super(value, "right"); }
}
/**
 * The `Right` data constructor represents the right side of the
 * [[Either]] disjoint union, as opposed to the [[Left]] side.
 */
export function Right(value) {
    return new TRight(value);
}
/**
 * Type-class implementations, compatible with the `static-land`
 * and `funland` specifications.
 *
 * See [funland-js.org](https://funland-js.org).
 */
export const EitherModule = {
    // Setoid
    equals: (x, y) => x ? x.equals(y) : !y,
    // Functor
    map: (f, fa) => fa.map(f),
    // Apply
    ap: (ff, fa) => fa.ap(ff),
    // Applicative
    of: Either.pure,
    // Chain
    chain: (f, fa) => fa.flatMap(f),
    // ChainRec
    chainRec: (f, a) => Either.tailRecM(a, a => f(Either.left, Either.right, a))
};
// Registers Fantasy-Land compatible symbols
fantasyLandRegister(Either, EitherModule, EitherModule);
/**
 * Represents optional values, inspired by Scala's `Option` and by
 * Haskell's `Maybe` data types.
 *
 * Option is an immutable data type, represented as a sum type, being
 * either a [[Some]], in case it contains a single element, or a [[None]],
 * in case it is empty.
 *
 * The most idiomatic way to use an `Option` instance is to treat it
 * as a collection or monad and use `map`,`flatMap`, `filter`,
 * or `forEach`.
 *
 * @final
 */
export class Option {
    constructor(ref, isEmpty) {
        /* tslint:disable-next-line:strict-type-predicates */
        this._isEmpty = isEmpty != null ? isEmpty : (ref === null || ref === undefined);
        this.value = ref;
    }
    /**
     * Returns the option's value.
     *
     * WARNING!
     *
     * This function is partial, the option must be non-empty, otherwise
     * a runtime exception will get thrown. Use with care.
     *
     * @throws [[NoSuchElementError]] in case the option is empty
     */
    get() {
        if (!this._isEmpty)
            return this.value;
        throw new NoSuchElementError("Option.get");
    }
    /**
     * Returns the option's value if the option is nonempty, otherwise
     * return the given `fallback`.
     *
     * See [[Option.getOrElseL]] for a lazy alternative.
     */
    getOrElse(fallback) {
        if (!this._isEmpty)
            return this.value;
        else
            return fallback;
    }
    /**
     * Returns the option's value if the option is nonempty, otherwise
     * return `null`.
     * ```
     */
    orNull() {
        return !this._isEmpty ? this.value : null;
    }
    /**
     * Returns the option's value if the option is nonempty, otherwise
     * return `undefined`.
     */
    orUndefined() {
        return !this._isEmpty ? this.value : undefined;
    }
    /**
     * Returns the option's value if the option is nonempty, otherwise
     * return the result of evaluating `thunk`.
     *
     * See [[Option.getOrElse]] for a strict alternative.
     */
    getOrElseL(thunk) {
        if (!this._isEmpty)
            return this.value;
        else
            return thunk();
    }
    /**
     * Returns this option if it is nonempty, otherwise returns the
     * given `fallback`.
     */
    orElse(fallback) {
        if (!this._isEmpty)
            return this;
        else
            return fallback;
    }
    /**
     * Returns this option if it is nonempty, otherwise returns the
     * given result of evaluating the given `thunk`.
     *
     * @param thunk a no-params function that gets evaluated and
     *        whose result is returned in case this option is empty
     */
    orElseL(thunk) {
        if (!this._isEmpty)
            return this;
        else
            return thunk();
    }
    /**
     * Returns `true` if the option is empty, `false` otherwise.
     */
    isEmpty() { return this._isEmpty; }
    /**
     * Returns `true` if the option is not empty, `false` otherwise.
     */
    nonEmpty() { return !this._isEmpty; }
    /**
     * Returns an option containing the result of applying `f` to
     * this option's value, or an empty option if the source is empty.
     *
     * NOTE: this is similar with `flatMap`, except with `map` the
     * result of `f` doesn't need to be wrapped in an `Option`.
     *
     * @param f the mapping function that will transform the value
     *          of this option if nonempty.
     *
     * @return a new option instance containing the value of the
     *         source mapped by the given function
     */
    map(f) {
        return this._isEmpty ? None : Some(f(this.value));
    }
    /**
     * Returns the result of applying `f` to this option's value if
     * the option is nonempty, otherwise returns an empty option.
     *
     * NOTE: this is similar with `map`, except that `flatMap` the
     * result returned by `f` is expected to be boxed in an `Option`
     * already.
     *
     * Example:
     *
     * ```typescript
     * const opt = Option.of(10)
     *
     * opt.flatMap(num => {
     *   if (num % 2 == 0)
     *     Some(num + 1)
     *   else
     *     None
     * })
     * ```
     *
     * @param f the mapping function that will transform the value
     *          of this option if nonempty.
     *
     * @return a new option instance containing the value of the
     *         source mapped by the given function
     */
    flatMap(f) {
        if (this._isEmpty)
            return None;
        else
            return f(this.value);
    }
    /** Alias for [[flatMap]]. */
    chain(f) {
        return this.flatMap(f);
    }
    /**
     * `Applicative` apply operator.
     *
     * Resembles {@link map}, but the passed mapping function is
     * lifted in the `Either` context.
     */
    ap(ff) {
        return ff.flatMap(f => this.map(f));
    }
    filter(p) {
        if (this._isEmpty || !p(this.value))
            return None;
        else
            return this;
    }
    /**
     * Returns the result of applying `f` to this option's value,
     * or in case the option is empty, the return the result of
     * evaluating the `fallback` function.
     *
     * This function is equivalent with:
     *
     * ```typescript
     * opt.map(f).getOrElseL(fallback)
     * ```
     *
     * @param fallback is the function to be evaluated in case this
     *        option is empty
     *
     * @param f is the mapping function for transforming this option's
     *        value in case it is nonempty
     */
    fold(fallback, f) {
        if (this._isEmpty)
            return fallback();
        return f(this.value);
    }
    /**
     * Returns true if this option is nonempty and the value it
     * holds is equal to the given `elem`.
     */
    contains(elem) {
        return !this._isEmpty && std.is(this.value, elem);
    }
    /**
     * Returns `true` if this option is nonempty and the given
     * predicate returns `true` when applied on this option's value.
     *
     * @param p is the predicate function to test
     */
    exists(p) {
        return !this._isEmpty && p(this.value);
    }
    /**
     * Returns true if this option is empty or the given predicate
     * returns `true` when applied on this option's value.
     *
     * @param p is the predicate function to test
     */
    forAll(p) {
        return this._isEmpty || p(this.value);
    }
    /**
     * Apply the given procedure `cb` to the option's value if
     * this option is nonempty, otherwise do nothing.
     *
     * @param cb the procedure to apply
     */
    forEach(cb) {
        if (!this._isEmpty)
            cb(this.value);
    }
    /**
     * Implements {@link IEquals.equals}.
     *
     * @param that is the right hand side of the equality check
     */
    equals(that) {
        // tslint:disable-next-line:strict-type-predicates
        if (that == null)
            return false;
        if (this.nonEmpty() && that.nonEmpty()) {
            return std.is(this.value, that.value);
        }
        return this.isEmpty() && that.isEmpty();
    }
    // Implemented from IEquals
    hashCode() {
        if (this._isEmpty)
            return 2433880;
        else if (this.value == null)
            return 2433881 << 2;
        else
            return std.hashCode(this.value) << 2;
    }
    /**
     * Builds an [[Option]] reference that contains the given value.
     *
     * If the given value is `null` or `undefined` then the returned
     * option will be empty.
     */
    static of(value) {
        return value != null ? Some(value) : None;
    }
    /**
     * Builds an [[Option]] reference that contains the given reference.
     *
     * Note that `value` is allowed to be `null` or `undefined`, the
     * returned option will still be non-empty. Use [[Option.of]]
     * if you want to avoid this problem. This means:
     *
     * ```typescript
     * const opt = Some<number | null>(null)
     *
     * opt.isEmpty()
     * //=> false
     *
     * opt.get()
     * //=> null
     * ```
     */
    static some(value) {
        return new Option(value, false);
    }
    /**
     * Returns an empty [[Option]].
     *
     * NOTE: Because `Option` is immutable, this function returns the
     * same cached reference is on different calls.
     */
    static none() {
        return None;
    }
    /**
     * Returns an empty [[Option]].
     *
     * Similar to [[Option.none]], but this one allows specifying a
     * type parameter (in the context of TypeScript or Flow or other
     * type system).
     *
     * NOTE: Because `Option` is immutable, this function returns the
     * same cached reference is on different calls.
     */
    static empty() {
        return None;
    }
    /**
     * Alias for [[Some]].
     */
    static pure(value) { return Some(value); }
    /**
     * Maps 2 optional values by the mapping function, returning a new
     * optional reference that is `Some` only if both option values are
     * `Some`, otherwise it returns a `None`.
     *
     * ```typescript
     * // Yields Some(3)
     * Option.map2(Some(1), Some(2),
     *   (a, b) => a + b
     * )
     *
     * // Yields None, because the second arg is None
     * Option.map2(Some(1), None,
     *   (a, b) => a + b
     * )
     * ```
     *
     * This operation is the `Applicative.map2`.
     */
    static map2(fa1, fa2, f) {
        return fa1.nonEmpty() && fa2.nonEmpty()
            ? Some(f(fa1.value, fa2.value))
            : None;
    }
    /**
     * Maps 3 optional values by the mapping function, returning a new
     * optional reference that is `Some` only if all 3 option values are
     * `Some`, otherwise it returns a `None`.
     *
     * ```typescript
     * // Yields Some(6)
     * Option.map3(Some(1), Some(2), Some(3),
     *   (a, b, c) => a + b + c
     * )
     *
     * // Yields None, because the second arg is None
     * Option.map3(Some(1), None, Some(3),
     *   (a, b, c) => a + b + c
     * )
     * ```
     */
    static map3(fa1, fa2, fa3, f) {
        return fa1.nonEmpty() && fa2.nonEmpty() && fa3.nonEmpty()
            ? Some(f(fa1.value, fa2.value, fa3.value))
            : None;
    }
    /**
     * Maps 4 optional values by the mapping function, returning a new
     * optional reference that is `Some` only if all 4 option values are
     * `Some`, otherwise it returns a `None`.
     *
     * ```typescript
     * // Yields Some(10)
     * Option.map4(Some(1), Some(2), Some(3), Some(4),
     *   (a, b, c, d) => a + b + c + d
     * )
     *
     * // Yields None, because the second arg is None
     * Option.map4(Some(1), None, Some(3), Some(4),
     *   (a, b, c, d) => a + b + c + d
     * )
     * ```
     */
    static map4(fa1, fa2, fa3, fa4, f) {
        return fa1.nonEmpty() && fa2.nonEmpty() && fa3.nonEmpty() && fa4.nonEmpty()
            ? Some(f(fa1.value, fa2.value, fa3.value, fa4.value))
            : None;
    }
    /**
     * Maps 5 optional values by the mapping function, returning a new
     * optional reference that is `Some` only if all 5 option values are
     * `Some`, otherwise it returns a `None`.
     *
     * ```typescript
     * // Yields Some(15)
     * Option.map5(Some(1), Some(2), Some(3), Some(4), Some(5),
     *   (a, b, c, d, e) => a + b + c + d + e
     * )
     *
     * // Yields None, because the second arg is None
     * Option.map5(Some(1), None, Some(3), Some(4), Some(5),
     *   (a, b, c, d, e) => a + b + c + d + e
     * )
     * ```
     */
    static map5(fa1, fa2, fa3, fa4, fa5, f) {
        return fa1.nonEmpty() && fa2.nonEmpty() && fa3.nonEmpty() && fa4.nonEmpty() && fa5.nonEmpty()
            ? Some(f(fa1.value, fa2.value, fa3.value, fa4.value, fa5.value))
            : None;
    }
    /**
     * Maps 6 optional values by the mapping function, returning a new
     * optional reference that is `Some` only if all 6 option values are
     * `Some`, otherwise it returns a `None`.
     *
     * ```typescript
     * // Yields Some(21)
     * Option.map6(Some(1), Some(2), Some(3), Some(4), Some(5), Some(6),
     *   (a, b, c, d, e, f) => a + b + c + d + e + f
     * )
     *
     * // Yields None, because the second arg is None
     * Option.map6(Some(1), None, Some(3), Some(4), Some(5), Some(6),
     *   (a, b, c, d, e, f) => a + b + c + d + e + f
     * )
     * ```
     */
    static map6(fa1, fa2, fa3, fa4, fa5, fa6, f) {
        return fa1.nonEmpty() && fa2.nonEmpty() && fa3.nonEmpty() && fa4.nonEmpty() && fa5.nonEmpty() && fa6.nonEmpty()
            ? Some(f(fa1.value, fa2.value, fa3.value, fa4.value, fa5.value, fa6.value))
            : None;
    }
    /**
     * Keeps calling `f` until a `Right(b)` is returned.
     *
     * Based on Phil Freeman's
     * [Stack Safety for Free]{@link http://functorial.com/stack-safety-for-free/index.pdf}.
     *
     * Described in `FlatMap.tailRecM`.
     */
    static tailRecM(a, f) {
        let cursor = a;
        while (true) {
            const result = f(cursor);
            if (result.nonEmpty()) {
                const some = result.value;
                if (some.isRight())
                    return Some(some.value);
                cursor = some.value;
            }
            else {
                return None;
            }
        }
    }
}
/**
 * Result of the [[Some]] data constructor, representing
 * non-empty values in the [[Option]] disjunction.
 */
export class TSome extends Option {
    constructor(value) { super(value, false); }
}
/**
 * The `Some<A>` data constructor for [[Option]] represents existing
 * values of type `A`.
 *
 * Using this function is equivalent with [[Option.some]].
 */
export function Some(value) {
    return new TSome(value);
}
/**
 * Result of the [[Some]] data constructor, representing
 * non-empty values in the [[Option]] disjunction.
 */
export class TNone extends Option {
    constructor() { super(undefined, true); }
}
/**
 * The `None` data constructor for [[Option]] represents non-existing
 * values for any type.
 *
 * Using this reference directly is equivalent with [[Option.none]].
 */
export const None = new TNone();
/**
 * Type-class implementations, compatible with the `static-land`
 * and `funland` specification.
 *
 * See [funland-js.org](https://funland-js.org).
 */
export const OptionModule = {
    // Setoid
    equals: (x, y) => x ? x.equals(y) : !y,
    // Functor
    map: (f, fa) => fa.map(f),
    // Apply
    ap: (ff, fa) => fa.ap(ff),
    // Applicative
    of: Option.pure,
    // Chain
    chain: (f, fa) => fa.flatMap(f),
    // ChainRec
    chainRec: (f, a) => Option.tailRecM(a, a => f(Either.left, Either.right, a))
};
// Registers Fantasy-Land compatible symbols
fantasyLandRegister(Option, OptionModule, OptionModule);
/**
 * The `Try` type represents a computation that may either result in an
 * exception, or return a successfully computed value. It's similar to,
 * but semantically different from the [[Either]] type.
 *
 * `Try` is a sum type and so instances of `Try` are either instances
 * of [[Success]] or of [[Failure]].
 *
 * For example, `Try` can be used to perform division on a user-defined
 * input, without the need to do explicit exception-handling in all of
 * the places that an exception might occur.
 *
 * Example:
 *
 * ```typescript
 * function divide(dividendS: string, divisorS: string): string {
 *   const dividend = Try(() => parseInt(dividendS))
 *     .filter(_ => _ === _) // filter out NaN
 *   const divisor = Try(() => parseInt(divisorS))
 *     .filter(_ => _ === _)  // filter out NaN
 *
 *   // map2 executes the given function only if both results are
 *   // successful; we could also express this with flatMap / chain
 *   const result = Try.map2(dividend, divisor,
 *     (a, b) => a / b
 *   )
 *
 *   result.fold(
 *     error => `failure: ${error}`
 *     result => `result: ${result}`
 *   )
 * }
 * ```
 *
 * An important property of `Try` is its ability to pipeline, or chain,
 * operations, catching exceptions along the way. The `flatMap` and `map`
 * combinators each essentially pass off either their successfully completed
 * value, wrapped in the [[Success]] type for it to be further operated upon
 * by the next combinator in the chain, or the exception wrapped in the
 * [[Failure]] type usually to be simply passed on down the chain.
 * Combinators such as `recover` and `recoverWith` are designed to provide
 * some type of global behavior in the case of failure.
 *
 * NOTE: all `Try` combinators will catch exceptions and return failure
 * unless otherwise specified in the documentation.
 */
export class Try {
    constructor(value, tag) {
        this._isSuccess = tag === "success";
        this.value = value;
    }
    /**
     * Returns `true` if the source is a [[Success]] result,
     * or `false` in case it is a [[Failure]].
     */
    isSuccess() { return this._isSuccess; }
    /**
     * Returns `true` if the source is a [[Failure]],
     * or `false` in case it is a [[Success]] result.
     */
    isFailure() { return !this._isSuccess; }
    /**
     * Returns a Try's successful value if it's a [[Success]] reference,
     * otherwise throws an exception if it's a [[Failure]].
     *
     * WARNING!
     *
     * This function is partial, the option must be non-empty, otherwise
     * a runtime exception will get thrown. Use with care.
     */
    get() {
        if (!this._isSuccess)
            throw this.value;
        return this.value;
    }
    /**
     * Returns the value from a `Success` or the given `fallback`
     * value if this is a `Failure`.
     *
     * ```typescript
     * Success(10).getOrElse(27) // 10
     * Failure("error").getOrElse(27)  // 27
     * ```
     */
    getOrElse(fallback) {
        return this._isSuccess ? this.value : fallback;
    }
    /**
     * Returns the value from a `Success` or the value generated
     * by a given `thunk` in case this is a `Failure`.
     *
     * ```typescript
     * Success(10).getOrElseL(() => 27) // 10
     * Failure("error").getOrElseL(() => 27)  // 27
     * ```
     */
    getOrElseL(thunk) {
        return this._isSuccess ? this.value : thunk();
    }
    /**
     * Returns the current value if it's a [[Success]], or
     * if the source is a [[Failure]] then return `null`.
     *
     * ```typescript
     * Success(10).orNull()      // 10
     * Failure("error").orNull() // null
     * ```
     *
     * This can be useful for use-cases such as:
     *
     * ```typescript
     * Try.of(() => dict.user.profile.name).orNull()
     * ```
     */
    orNull() {
        return this._isSuccess ? this.value : null;
    }
    /**
     * Returns the current value if it's a [[Success]], or
     * if the source is a [[Failure]] then return `undefined`.
     *
     * ```typescript
     * Success(10).orUndefined()      // 10
     * Failure("error").orUndefined() // undefined
     * ```
     *
     * This can be useful for use-cases such as:
     *
     * ```typescript
     * Try.of(() => dict.user.profile.name).orUndefined()
     * ```
     */
    orUndefined() {
        return this._isSuccess ? this.value : undefined;
    }
    /**
     * Returns the current value if it's a [[Success]], or if
     * the source is a [[Failure]] then return the `fallback`.
     *
     * ```typescript
     * Success(10).orElse(Success(17))      // 10
     * Failure("error").orElse(Success(17)) // 17
     * ```
     */
    orElse(fallback) {
        if (this._isSuccess)
            return this;
        return fallback;
    }
    /**
     * Returns the current value if it's a [[Success]], or if the source
     * is a [[Failure]] then return the value generated by the given
     * `thunk`.
     *
     * ```typescript
     * Success(10).orElseL(() => Success(17))      // 10
     * Failure("error").orElseL(() => Success(17)) // 17
     * ```
     */
    orElseL(thunk) {
        if (this._isSuccess)
            return this;
        return thunk();
    }
    /**
     * Inverts this `Try`. If this is a [[Failure]], returns its exception wrapped
     * in a [[Success]]. If this is a `Success`, returns a `Failure` containing a
     * [[NoSuchElementError]].
     */
    failed() {
        return this._isSuccess
            ? Failure(new NoSuchElementError("try.failed()"))
            : Success(this.value);
    }
    /**
     * Applies the `failure` function to [[Failure]] values, and the
     * `success` function to [[Success]] values and returns the result.
     *
     * ```typescript
     * const maybeNum: Try<number> =
     *   tryParseInt("not a number")
     *
     * const result: string =
     *   maybeNum.fold(
     *     error => `Could not parse string: ${error}`,
     *     num => `Success: ${num}`
     *   )
     * ```
     */
    fold(failure, success) {
        return this._isSuccess
            ? success(this.value)
            : failure(this.value);
    }
    filter(p) {
        if (!this._isSuccess)
            return this;
        try {
            if (p(this.value))
                return this;
            return Failure(new NoSuchElementError(`Predicate does not hold for ${this.value}`));
        }
        catch (e) {
            return Failure(e);
        }
    }
    /**
     * Returns the given function applied to the value if this is
     * a [[Success]] or returns `this` if this is a [[Failure]].
     *
     * This operation is the monadic "bind" operation.
     * It can be used to *chain* multiple `Try` references.
     *
     * ```typescript
     * Try.of(() => parse(s1)).flatMap(num1 =>
     *   Try.of(() => parse(s2)).map(num2 =>
     *     num1 / num2
     *   ))
     * ```
     */
    flatMap(f) {
        if (!this._isSuccess)
            return this;
        try {
            return f(this.value);
        }
        catch (e) {
            return Failure(e);
        }
    }
    /** Alias for [[flatMap]]. */
    chain(f) {
        return this.flatMap(f);
    }
    /**
     * `Applicative` apply operator.
     *
     * Resembles {@link map}, but the passed mapping function is
     * lifted in the `Either` context.
     */
    ap(ff) {
        return ff.flatMap(f => this.map(f));
    }
    /**
     * Returns a `Try` containing the result of applying `f` to
     * this option's value, but only if it's a `Success`, or
     * returns the current `Failure` without any modifications.
     *
     * NOTE: this is similar with `flatMap`, except with `map` the
     * result of `f` doesn't need to be wrapped in a `Try`.
     *
     * @param f the mapping function that will transform the value
     *          of this `Try` if successful.
     *
     * @return a new `Try` instance containing the value of the
     *         source mapped by the given function
     */
    map(f) {
        return this._isSuccess
            ? Try.of(() => f(this.value))
            : this;
    }
    /**
     * Applies the given function `cb` if this is a [[Success]], otherwise
     * returns `void` if this is a [[Failure]].
     */
    forEach(cb) {
        if (this._isSuccess)
            cb(this.value);
    }
    /**
     * Applies the given function `f` if this is a `Failure`, otherwise
     * returns `this` if this is a `Success`.
     *
     * This is like `map` for the exception.
     *
     * In the following example, if the `user.profile.email` exists,
     * then it is returned as a successful value, otherwise
     *
     * ```typescript
     * Try.of(() => user.profile.email).recover(e => {
     *   // Access error? Default to empty.
     *   if (e instanceof TypeError) return ""
     *   throw e // We don't know what it is, rethrow
     * })
     *
     * Note that on rethrow, the error is being caught in `recover` and
     * it still returns it as a `Failure(e)`.
     * ```
     */
    recover(f) {
        return this._isSuccess
            ? this
            : Try.of(() => f(this.value));
    }
    /**
     * Applies the given function `f` if this is a `Failure`, otherwise
     * returns `this` if this is a `Success`.
     *
     * This is like `map` for the exception.
     *
     * In the following example, if the `user.profile.email` exists,
     * then it is returned as a successful value, otherwise
     *
     * ```typescript
     * Try.of(() => user.profile.email).recover(e => {
     *   // Access error? Default to empty.
     *   if (e instanceof TypeError) return ""
     *   throw e // We don't know what it is, rethrow
     * })
     *
     * Note that on rethrow, the error is being caught in `recover` and
     * it still returns it as a `Failure(e)`.
     * ```
     */
    recoverWith(f) {
        try {
            return this._isSuccess ? this : f(this.value);
        }
        catch (e) {
            return Failure(e);
        }
    }
    /**
     * Transforms the source into an [[Option]].
     *
     * In case the source is a `Success(v)`, then it gets translated
     * into a `Some(v)`. If the source is a `Failure(e)`, then a `None`
     * value is returned.
     *
     * ```typescript
     * Success("value").toOption() // Some("value")
     * Failure("error").toOption() // None
     * ```
     */
    toOption() {
        return this._isSuccess ? Some(this.value) : None;
    }
    /**
     * Transforms the source into an [[Either]].
     *
     * In case the source is a `Success(v)`, then it gets translated
     * into a `Right(v)`. If the source is a `Failure(e)`, then a `Left(e)`
     * value is returned.
     *
     * ```typescript
     * Success("value").toEither() // Right("value")
     * Failure("error").toEither() // Left("error")
     * ```
     */
    toEither() {
        return this._isSuccess
            ? Right(this.value)
            : Left(this.value);
    }
    /**
     * Implements {@link IEquals.equals} with overridable equality for `A`.
     */
    equals(that) {
        // tslint:disable-next-line:strict-type-predicates
        if (that == null)
            return false;
        return this._isSuccess
            ? that._isSuccess && std.is(this.value, that.value)
            : !that._isSuccess && std.is(this.value, that.value);
    }
    // Implemented from IEquals
    hashCode() {
        return this._isSuccess
            ? std.hashCode(this.value)
            : std.hashCode(this.value);
    }
    /**
     * Evaluates the given `thunk` and returns either a [[Success]],
     * in case the evaluation succeeded, or a [[Failure]], in case
     * an exception was thrown.
     *
     * Example:
     *
     * ```typescript
     * let effect = 0
     *
     * const e = Try.of(() => { effect += 1; return effect })
     * e.get() // 1
     * ```
     */
    static of(thunk) {
        try {
            return Success(thunk());
        }
        catch (e) {
            return Failure(e);
        }
    }
    /** Alias of [[Try.success]]. */
    static pure(value) {
        return Try.success(value);
    }
    /**
     * Shorthand for `now(undefined as void)`, always returning
     * the same reference as optimization.
     */
    static unit() {
        return tryUnitRef;
    }
    /**
     * Returns a [[Try]] reference that represents a successful result
     * (i.e. wrapped in [[Success]]).
     */
    static success(value) {
        return Success(value);
    }
    /**
     * Returns a [[Try]] reference that represents a failure
     * (i.e. an exception wrapped in [[Failure]]).
     */
    static failure(e) {
        return Failure(e);
    }
    /**
     * Alias for {@link Try.failure} and {@link Failure},
     * wrapping any throwable into a `Try` value.
     */
    static raise(e) {
        return Failure(e);
    }
    /**
     * Maps 2 `Try` values by the mapping function, returning a new
     * `Try` reference that is a `Success` only if both `Try` values are
     * a `Success`, otherwise it returns the first `Failure` noticed.
     *
     * ```typescript
     * // Yields Success(3)
     * Try.map2(Success(1), Success(2),
     *   (a, b) => a + b
     * )
     *
     * // Yields Failure, because the second arg is a Failure
     * Try.map2(Success(1), Failure("error"),
     *   (a, b) => a + b
     * )
     * ```
     *
     * This operation is the `Applicative.map2`.
     */
    static map2(fa1, fa2, f) {
        if (fa1.isFailure())
            return fa1;
        if (fa2.isFailure())
            return fa2;
        try {
            return Success(f(fa1.value, fa2.value));
        }
        catch (e) {
            return Failure(e);
        }
    }
    /**
     * Maps 3 `Try` values by the mapping function, returning a new
     * `Try` reference that is a `Success` only if all 3 `Try` values are
     * a `Success`, otherwise it returns the first `Failure` noticed.
     *
     * ```typescript
     * // Yields Success(6)
     * Try.map3(Success(1), Success(2), Success(3),
     *   (a, b, c) => {
     *     return a + b + c
     *   }
     * )
     *
     * // Yields Failure, because the second arg is a Failure
     * Try.map3(
     *   Success(1),
     *   Failure("error"),
     *   Success(3),
     *
     *   (a, b, c) => {
     *     return a + b + c
     *   }
     * )
     * ```
     */
    static map3(fa1, fa2, fa3, f) {
        if (fa1.isFailure())
            return fa1;
        if (fa2.isFailure())
            return fa2;
        if (fa3.isFailure())
            return fa3;
        try {
            return Success(f(fa1.value, fa2.value, fa3.value));
        }
        catch (e) {
            return Failure(e);
        }
    }
    /**
     * Maps 4 `Try` values by the mapping function, returning a new
     * `Try` reference that is a `Success` only if all 4 `Try` values are
     * a `Success`, otherwise it returns the first `Failure` noticed.
     *
     * ```typescript
     * // Yields Success(10)
     * Try.map4(Success(1), Success(2), Success(3), Success(4),
     *   (a, b, c, d) => {
     *     return a + b + c + d
     *   }
     * )
     *
     * // Yields Failure, because the second arg is a Failure
     * Try.map3(
     *   Success(1),
     *   Failure("error"),
     *   Success(3),
     *   Success(4),
     *
     *   (a, b, c, d) => {
     *     return a + b + c + d
     *   }
     * )
     * ```
     */
    static map4(fa1, fa2, fa3, fa4, f) {
        if (fa1.isFailure())
            return fa1;
        if (fa2.isFailure())
            return fa2;
        if (fa3.isFailure())
            return fa3;
        if (fa4.isFailure())
            return fa4;
        try {
            return Success(f(fa1.value, fa2.value, fa3.value, fa4.value));
        }
        catch (e) {
            return Failure(e);
        }
    }
    /**
     * Maps 5 `Try` values by the mapping function, returning a new
     * `Try` reference that is a `Success` only if all 5 `Try` values are
     * a `Success`, otherwise it returns the first `Failure` noticed.
     *
     * ```typescript
     * // Yields Success(15)
     * Try.map5(
     *   Success(1),
     *   Success(2),
     *   Success(3),
     *   Success(4),
     *   Success(5),
     *
     *   (a, b, c, d, e) => {
     *     return a + b + c + d + e
     *   }
     * )
     *
     * // Yields Failure, because the second arg is a Failure
     * Try.map5(
     *   Success(1),
     *   Failure("error"),
     *   Success(3),
     *   Success(4),
     *   Success(5),
     *
     *   (a, b, c, d, e) => {
     *     return a + b + c + d + e
     *   }
     * )
     * ```
     */
    static map5(fa1, fa2, fa3, fa4, fa5, f) {
        if (fa1.isFailure())
            return fa1;
        if (fa2.isFailure())
            return fa2;
        if (fa3.isFailure())
            return fa3;
        if (fa4.isFailure())
            return fa4;
        if (fa5.isFailure())
            return fa5;
        try {
            return Success(f(fa1.value, fa2.value, fa3.value, fa4.value, fa5.value));
        }
        catch (e) {
            return Failure(e);
        }
    }
    /**
     * Maps 6 `Try` values by the mapping function, returning a new
     * `Try` reference that is a `Success` only if all 6 `Try` values are
     * a `Success`, otherwise it returns the first `Failure` noticed.
     *
     * ```typescript
     * // Yields Success(21)
     * Try.map6(
     *   Success(1),
     *   Success(2),
     *   Success(3),
     *   Success(4),
     *   Success(5),
     *   Success(6),
     *
     *   (a, b, c, d, e, f) => {
     *     return a + b + c + d + e + f
     *   }
     * )
     *
     * // Yields Failure, because the second arg is a Failure
     * Try.map6(
     *   Success(1),
     *   Failure("error"),
     *   Success(3),
     *   Success(4),
     *   Success(5),
     *   Success(6),
     *
     *   (a, b, c, d, e, f) => {
     *     return a + b + c + d + e + f
     *   }
     * )
     * ```
     */
    static map6(fa1, fa2, fa3, fa4, fa5, fa6, f) {
        if (fa1.isFailure())
            return fa1;
        if (fa2.isFailure())
            return fa2;
        if (fa3.isFailure())
            return fa3;
        if (fa4.isFailure())
            return fa4;
        if (fa5.isFailure())
            return fa5;
        if (fa6.isFailure())
            return fa6;
        try {
            return Success(f(fa1.value, fa2.value, fa3.value, fa4.value, fa5.value, fa6.value));
        }
        catch (e) {
            return Failure(e);
        }
    }
    /**
     * Keeps calling `f` until a `Right(b)` is returned.
     *
     * Based on Phil Freeman's
     * [Stack Safety for Free]{@link http://functorial.com/stack-safety-for-free/index.pdf}.
     *
     * Described in `FlatMap.tailRecM`.
     */
    static tailRecM(a, f) {
        let cursor = a;
        while (true) {
            try {
                const result = f(cursor);
                if (result.isFailure())
                    return result;
                const some = result.get();
                if (some.isRight())
                    return Success(some.value);
                cursor = some.value;
            }
            catch (e) {
                return Failure(e);
            }
        }
    }
}
/**
 * Result of the [[Success]] data constructor, representing
 * successful values in the [[Try]] disjunction.
 *
 * @final
 */
export class TSuccess extends Try {
    constructor(value) { super(value, "success"); }
}
/**
 * The `Success` data constructor is for building [[Try]] values that
 * are successful results of computations, as opposed to [[Failure]].
 */
export function Success(value) {
    return new TSuccess(value);
}
/**
 * The `Success` data constructor is for building [[Try]] values that
 * are successful results of computations, as opposed to [[Failure]].
 *
 * @final
 */
export class TFailure extends Try {
    constructor(value) { super(value, "failure"); }
}
/**
 * The `Failure` data constructor is for building [[Try]] values that
 * represent failures, as opposed to [[Success]].
 */
export function Failure(e) {
    return new TFailure(e);
}
/**
 * Type-class implementations, compatible with the `static-land`
 * and `funland` specifications.
 *
 * See [funland-js.org](https://funland-js.org).
 */
export const TryModule = {
    // Setoid
    equals: (x, y) => x ? x.equals(y) : !y,
    // Functor
    map: (f, fa) => fa.map(f),
    // Apply
    ap: (ff, fa) => fa.ap(ff),
    // Applicative
    of: Try.pure,
    // Chain
    chain: (f, fa) => fa.flatMap(f),
    // ChainRec
    chainRec: (f, a) => Try.tailRecM(a, a => f(Either.left, Either.right, a))
};
// Registers Fantasy-Land compatible symbols
fantasyLandRegister(Try, TryModule, TryModule);
/**
 * Reusable reference, to use in {@link Try.unit}.
 *
 * @private
 * @hidden
 */
const tryUnitRef = Success(undefined);
//# sourceMappingURL=disjunctions.js.map