import { apFirst as apFirst_, apS as apS_, apSecond as apSecond_ } from './Apply';
import { bind as bind_, chainFirst as chainFirst_ } from './Chain';
import { fromEitherK as fromEitherK_ } from './FromEither';
import { identity, pipe } from './function';
import { let as let__, bindTo as bindTo_, flap as flap_ } from './Functor';
import * as _ from './internal';
import * as NEA from './NonEmptyArray';
import * as RA from './ReadonlyArray';
import { separated } from './Separated';
import { filterE as filterE_, wiltDefault, witherDefault } from './Witherable';
import { guard as guard_ } from './Zero';
// -------------------------------------------------------------------------------------
// refinements
// -------------------------------------------------------------------------------------
/**
* Test whether an array is empty
*
* @example
* import { isEmpty } from 'fp-ts/Array'
*
* assert.strictEqual(isEmpty([]), true)
* assert.strictEqual(isEmpty(['a']), false)
*
* @category refinements
* @since 2.0.0
*/
export var isEmpty = function (as) { return as.length === 0; };
/**
* Test whether an array is non empty narrowing down the type to `NonEmptyArray`
*
* @example
* import { isNonEmpty } from 'fp-ts/Array'
*
* assert.strictEqual(isNonEmpty([]), false)
* assert.strictEqual(isNonEmpty(['a']), true)
*
* @category refinements
* @since 2.0.0
*/
export var isNonEmpty = NEA.isNonEmpty;
// -------------------------------------------------------------------------------------
// constructors
// -------------------------------------------------------------------------------------
/**
* Prepend an element to the front of a `Array`, creating a new `NonEmptyArray`.
*
* @example
* import { prepend } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(pipe([2, 3, 4], prepend(1)), [1, 2, 3, 4])
*
* @since 2.10.0
*/
export var prepend = NEA.prepend;
/**
* Less strict version of [`prepend`](#prepend).
*
* @example
* import { prependW } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(pipe([2, 3, 4], prependW("a")), ["a", 2, 3, 4]);
*
* @since 2.11.0
*/
export var prependW = NEA.prependW;
/**
* Append an element to the end of a `Array`, creating a new `NonEmptyArray`.
*
* @example
* import { append } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(pipe([1, 2, 3], append(4)), [1, 2, 3, 4])
*
* @since 2.10.0
*/
export var append = NEA.append;
/**
* Less strict version of [`append`](#append).
*
* @example
* import { appendW } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(pipe([1, 2, 3], appendW("d")), [1, 2, 3, "d"]);
*
* @since 2.11.0
*/
export var appendW = NEA.appendW;
/**
* Return a `Array` of length `n` with element `i` initialized with `f(i)`.
*
* **Note**. `n` is normalized to a non negative integer.
*
* @example
* import { makeBy } from 'fp-ts/Array'
*
* const double = (i: number): number => i * 2
* assert.deepStrictEqual(makeBy(5, double), [0, 2, 4, 6, 8])
* assert.deepStrictEqual(makeBy(-3, double), [])
* assert.deepStrictEqual(makeBy(4.32164, double), [0, 2, 4, 6])
*
* @category constructors
* @since 2.0.0
*/
export var makeBy = function (n, f) { return (n <= 0 ? [] : NEA.makeBy(f)(n)); };
/**
* Create a `Array` containing a value repeated the specified number of times.
*
* **Note**. `n` is normalized to a non negative integer.
*
* @example
* import { replicate } from 'fp-ts/Array'
*
* assert.deepStrictEqual(replicate(3, 'a'), ['a', 'a', 'a'])
* assert.deepStrictEqual(replicate(-3, 'a'), [])
* assert.deepStrictEqual(replicate(2.985647, 'a'), ['a', 'a'])
*
* @category constructors
* @since 2.0.0
*/
export var replicate = function (n, a) { return makeBy(n, function () { return a; }); };
export function fromPredicate(predicate) {
return function (a) { return (predicate(a) ? [a] : []); };
}
// -------------------------------------------------------------------------------------
// conversions
// -------------------------------------------------------------------------------------
/**
* Create an array from an `Option`. The resulting array will contain the content of the
* `Option` if it is `Some` and it will be empty if the `Option` is `None`.
*
* @example
* import { fromOption } from 'fp-ts/Array'
* import { option } from "fp-ts";
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(pipe(option.some("a"), fromOption),["a"])
* assert.deepStrictEqual(pipe(option.none, fromOption),[])
*
* @category conversions
* @since 2.11.0
*/
export var fromOption = function (ma) { return (_.isNone(ma) ? [] : [ma.value]); };
/**
* Create an array from an `Either`. The resulting array will contain the content of the
* `Either` if it is `Right` and it will be empty if the `Either` is `Left`.
*
* @example
* import { fromEither } from 'fp-ts/Array'
* import { either } from "fp-ts";
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(pipe(either.right("r"), fromEither), ["r"]);
* assert.deepStrictEqual(pipe(either.left("l"), fromEither), []);
*
* @category conversions
* @since 2.11.0
*/
export var fromEither = function (e) { return (_.isLeft(e) ? [] : [e.right]); };
/**
* Less strict version of [`match`](#match).
*
* The `W` suffix (short for **W**idening) means that the handler return types will be merged.
*
* @example
* import { matchW } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* const matcherW = matchW(
* () => "No elements",
* (as) => as.length
* );
* assert.deepStrictEqual(pipe([1, 2, 3, 4], matcherW), 4);
* assert.deepStrictEqual(pipe([], matcherW), "No elements");
*
* @category pattern matching
* @since 2.11.0
*/
export var matchW = function (onEmpty, onNonEmpty) {
return function (as) {
return isNonEmpty(as) ? onNonEmpty(as) : onEmpty();
};
};
/**
* Takes an array, if the array is empty it returns the result of `onEmpty`, otherwise
* it passes the array to `onNonEmpty` and returns the result.
*
* @example
* import { match } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* const matcher = match(
* () => "No elements",
* (as) => `Found ${as.length} element(s)`
* );
* assert.deepStrictEqual(pipe([1, 2, 3, 4], matcher), "Found 4 element(s)");
* assert.deepStrictEqual(pipe([], matcher), "No elements");
*
* @category pattern matching
* @since 2.11.0
*/
export var match = matchW;
/**
* Less strict version of [`matchLeft`](#matchleft). It will work when `onEmpty` and
* `onNonEmpty` have different return types.
*
* @example
* import { matchLeftW } from 'fp-ts/Array'
*
* const f = matchLeftW(
* () => 0,
* (head: string, tail: string[]) => `Found "${head}" followed by ${tail.length} elements`
* );
* assert.strictEqual(f(["a", "b", "c"]), 'Found "a" followed by 2 elements');
* assert.strictEqual(f([]), 0);
*
* @category pattern matching
* @since 2.11.0
*/
export var matchLeftW = function (onEmpty, onNonEmpty) {
return function (as) {
return isNonEmpty(as) ? onNonEmpty(NEA.head(as), NEA.tail(as)) : onEmpty();
};
};
/**
* Takes an array, if the array is empty it returns the result of `onEmpty`, otherwise
* it passes the array to `onNonEmpty` broken into its first element and remaining elements.
*
* @example
* import { matchLeft } from 'fp-ts/Array'
*
* const len: (as: Array) => number = matchLeft(() => 0, (_, tail) => 1 + len(tail))
* assert.strictEqual(len([1, 2, 3]), 3)
*
* @category pattern matching
* @since 2.10.0
*/
export var matchLeft = matchLeftW;
/**
* Alias of [`matchLeft`](#matchleft).
*
* @category pattern matching
* @since 2.0.0
*/
export var foldLeft = matchLeft;
/**
* Less strict version of [`matchRight`](#matchright). It will work when `onEmpty` and
* `onNonEmpty` have different return types.
*
* @example
* import { matchRightW } from 'fp-ts/Array'
*
* const f = matchRightW(
* () => 0,
* (head: string[], tail: string) => `Found ${head.length} elements folllowed by "${tail}"`
* );
* assert.strictEqual(f(["a", "b", "c"]), 'Found 2 elements folllowed by "c"');
* assert.strictEqual(f([]), 0);
*
* @category pattern matching
* @since 2.11.0
*/
export var matchRightW = function (onEmpty, onNonEmpty) {
return function (as) {
return isNonEmpty(as) ? onNonEmpty(NEA.init(as), NEA.last(as)) : onEmpty();
};
};
/**
* Takes an array, if the array is empty it returns the result of `onEmpty`, otherwise
* it passes the array to `onNonEmpty` broken into its initial elements and the last element.
*
* @example
* import { matchRight } from 'fp-ts/Array'
*
* const len: (as: Array) => number = matchRight(
* () => 0,
* (head, _) => 1 + len(head)
* );
* assert.strictEqual(len([1, 2, 3]), 3);
*
* @category pattern matching
* @since 2.10.0
*/
export var matchRight = matchRightW;
/**
* Alias of [`matchRight`](#matchright).
*
* @category pattern matching
* @since 2.0.0
*/
export var foldRight = matchRight;
// -------------------------------------------------------------------------------------
// combinators
// -------------------------------------------------------------------------------------
/**
* Same as [`chain`](#chain), but passing also the index to the iterating function.
*
* @example
* import { chainWithIndex, replicate } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* const f = (index: number, x: string) => replicate(2, `${x}${index}`);
* assert.deepStrictEqual(pipe(["a", "b", "c"], chainWithIndex(f)), ["a0", "a0", "b1", "b1", "c2", "c2"]);
*
* @category sequencing
* @since 2.7.0
*/
export var chainWithIndex = function (f) {
return function (as) {
var out = [];
for (var i = 0; i < as.length; i++) {
out.push.apply(out, f(i, as[i]));
}
return out;
};
};
/**
* Same as `reduce` but it carries over the intermediate steps
*
* @example
* import { scanLeft } from 'fp-ts/Array'
*
* assert.deepStrictEqual(scanLeft(10, (b, a: number) => b - a)([1, 2, 3]), [10, 9, 7, 4])
*
* @since 2.0.0
*/
export var scanLeft = function (b, f) {
return function (as) {
var len = as.length;
var out = new Array(len + 1);
out[0] = b;
for (var i = 0; i < len; i++) {
out[i + 1] = f(out[i], as[i]);
}
return out;
};
};
/**
* Fold an array from the right, keeping all intermediate results instead of only the final result
*
* @example
* import { scanRight } from 'fp-ts/Array'
*
* assert.deepStrictEqual(scanRight(10, (a: number, b) => b - a)([1, 2, 3]), [4, 5, 7, 10])
*
* @since 2.0.0
*/
export var scanRight = function (b, f) {
return function (as) {
var len = as.length;
var out = new Array(len + 1);
out[len] = b;
for (var i = len - 1; i >= 0; i--) {
out[i] = f(as[i], out[i + 1]);
}
return out;
};
};
/**
* Calculate the number of elements in a `Array`.
*
* @example
* import { size } from 'fp-ts/Array'
*
* assert.strictEqual(size(["a","b","c"]),3)
*
* @since 2.10.0
*/
export var size = function (as) { return as.length; };
/**
* Test whether an array contains a particular index
*
* @example
* import { isOutOfBound } from 'fp-ts/Array'
*
* assert.strictEqual(isOutOfBound(1,["a","b","c"]),false)
* assert.strictEqual(isOutOfBound(-1,["a","b","c"]),true)
* assert.strictEqual(isOutOfBound(3,["a","b","c"]),true)
*
* @since 2.0.0
*/
export var isOutOfBound = NEA.isOutOfBound;
// TODO: remove non-curried overloading in v3
/**
* This function provides a safe way to read a value at a particular index from an array.
* It returns a `none` if the index is out of bounds, and a `some` of the element if the
* index is valid.
*
* @example
* import { lookup } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(pipe([1, 2, 3], lookup(1)), some(2))
* assert.deepStrictEqual(pipe([1, 2, 3], lookup(3)), none)
*
* @since 2.0.0
*/
export var lookup = RA.lookup;
/**
* Get the first element in an array, or `None` if the array is empty
*
* @example
* import { head } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* assert.deepStrictEqual(head([1, 2, 3]), some(1))
* assert.deepStrictEqual(head([]), none)
*
* @since 2.0.0
*/
export var head = RA.head;
/**
* Get the last element in an array, or `None` if the array is empty
*
* @example
* import { last } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* assert.deepStrictEqual(last([1, 2, 3]), some(3))
* assert.deepStrictEqual(last([]), none)
*
* @since 2.0.0
*/
export var last = RA.last;
/**
* Get all but the first element of an array, creating a new array, or `None` if the array is empty
*
* @example
* import { tail } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* assert.deepStrictEqual(tail([1, 2, 3]), some([2, 3]))
* assert.deepStrictEqual(tail([]), none)
*
* @since 2.0.0
*/
export var tail = function (as) { return (isNonEmpty(as) ? _.some(NEA.tail(as)) : _.none); };
/**
* Get all but the last element of an array, creating a new array, or `None` if the array is empty
*
* @example
* import { init } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* assert.deepStrictEqual(init([1, 2, 3]), some([1, 2]))
* assert.deepStrictEqual(init([]), none)
*
* @since 2.0.0
*/
export var init = function (as) { return (isNonEmpty(as) ? _.some(NEA.init(as)) : _.none); };
/**
* Keep only a max number of elements from the start of an `Array`, creating a new `Array`.
*
* **Note**. `n` is normalized to a non negative integer.
*
* @example
* import { takeLeft } from 'fp-ts/Array'
*
* assert.deepStrictEqual(takeLeft(2)([1, 2, 3, 4, 5]), [1, 2]);
* assert.deepStrictEqual(takeLeft(7)([1, 2, 3, 4, 5]), [1, 2, 3, 4, 5]);
* assert.deepStrictEqual(takeLeft(0)([1, 2, 3, 4, 5]), []);
* assert.deepStrictEqual(takeLeft(-1)([1, 2, 3, 4, 5]), [1, 2, 3, 4, 5]);
*
* @since 2.0.0
*/
export var takeLeft = function (n) {
return function (as) {
return isOutOfBound(n, as) ? copy(as) : as.slice(0, n);
};
};
/**
* Keep only a max number of elements from the end of an `Array`, creating a new `Array`.
*
* **Note**. `n` is normalized to a non negative integer.
*
* @example
* import { takeRight } from 'fp-ts/Array'
*
* assert.deepStrictEqual(takeRight(2)([1, 2, 3, 4, 5]), [4, 5]);
* assert.deepStrictEqual(takeRight(7)([1, 2, 3, 4, 5]), [1, 2, 3, 4, 5]);
* assert.deepStrictEqual(takeRight(0)([1, 2, 3, 4, 5]), []);
* assert.deepStrictEqual(takeRight(-1)([1, 2, 3, 4, 5]), [1, 2, 3, 4, 5]);
*
* @since 2.0.0
*/
export var takeRight = function (n) {
return function (as) {
return isOutOfBound(n, as) ? copy(as) : n === 0 ? [] : as.slice(-n);
};
};
export function takeLeftWhile(predicate) {
return function (as) {
var out = [];
for (var _i = 0, as_1 = as; _i < as_1.length; _i++) {
var a = as_1[_i];
if (!predicate(a)) {
break;
}
out.push(a);
}
return out;
};
}
var spanLeftIndex = function (as, predicate) {
var l = as.length;
var i = 0;
for (; i < l; i++) {
if (!predicate(as[i])) {
break;
}
}
return i;
};
export function spanLeft(predicate) {
return function (as) {
var _a = splitAt(spanLeftIndex(as, predicate))(as), init = _a[0], rest = _a[1];
return { init: init, rest: rest };
};
}
/**
* Creates a new `Array` which is a copy of the input dropping a max number of elements from the start.
*
* **Note**. `n` is normalized to a non negative integer.
*
* @example
* import { dropLeft } from 'fp-ts/Array'
*
* assert.deepStrictEqual(dropLeft(2)([1, 2, 3]), [3]);
* assert.deepStrictEqual(dropLeft(5)([1, 2, 3]), []);
* assert.deepStrictEqual(dropLeft(0)([1, 2, 3]), [1, 2, 3]);
* assert.deepStrictEqual(dropLeft(-2)([1, 2, 3]), [1, 2, 3]);
*
* @since 2.0.0
*/
export var dropLeft = function (n) {
return function (as) {
return n <= 0 || isEmpty(as) ? copy(as) : n >= as.length ? [] : as.slice(n, as.length);
};
};
/**
* Creates a new `Array` which is a copy of the input dropping a max number of elements from the end.
*
* **Note**. `n` is normalized to a non negative integer.
*
* @example
* import { dropRight } from 'fp-ts/Array'
*
* assert.deepStrictEqual(dropRight(2)([1, 2, 3]), [1]);
* assert.deepStrictEqual(dropRight(5)([1, 2, 3]), []);
* assert.deepStrictEqual(dropRight(0)([1, 2, 3]), [1, 2, 3]);
* assert.deepStrictEqual(dropRight(-2)([1, 2, 3]), [1, 2, 3]);
*
* @since 2.0.0
*/
export var dropRight = function (n) {
return function (as) {
return n <= 0 || isEmpty(as) ? copy(as) : n >= as.length ? [] : as.slice(0, as.length - n);
};
};
export function dropLeftWhile(predicate) {
return function (as) { return as.slice(spanLeftIndex(as, predicate)); };
}
/**
* `findIndex` returns an `Option` containing the first index for which a predicate holds.
* It returns `None` if no element satisfies the predicate.
* Similar to [`findFirst`](#findFirst) but returning the index instead of the element.
*
* @example
* import { findIndex } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* assert.deepStrictEqual(findIndex((n: number) => n === 2)([1, 2, 3]), some(1))
* assert.deepStrictEqual(findIndex((n: number) => n === 2)([]), none)
*
* @since 2.0.0
*/
export var findIndex = RA.findIndex;
export function findFirst(predicate) {
return RA.findFirst(predicate);
}
/**
* Given a selector function which takes an element and returns an option,
* this function applies the selector to each element of the array and
* returns the first `Some` result. Otherwise it returns `None`.
*
* @example
* import { findFirstMap } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* interface Person {
* readonly name: string;
* readonly age: number;
* }
*
* const persons: Array = [
* { name: "John", age: 16 },
* { name: "Mary", age: 45 },
* { name: "Joey", age: 28 },
* ];
*
* const nameOfPersonAbove18 = (p: Person) => (p.age <= 18 ? none : some(p.name));
* const nameOfPersonAbove70 = (p: Person) => (p.age <= 70 ? none : some(p.name));
* assert.deepStrictEqual(findFirstMap(nameOfPersonAbove18)(persons), some("Mary"));
* assert.deepStrictEqual(findFirstMap(nameOfPersonAbove70)(persons), none);
*
* @since 2.0.0
*/
export var findFirstMap = RA.findFirstMap;
export function findLast(predicate) {
return RA.findLast(predicate);
}
/**
* Given a selector function which takes an element and returns an option,
* this function applies the selector to each element of the array starting from the
* end and returns the last `Some` result. Otherwise it returns `None`.
*
* @example
* import { findLastMap } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* interface Person {
* readonly name: string;
* readonly age: number;
* }
*
* const persons: Array = [
* { name: "John", age: 16 },
* { name: "Mary", age: 45 },
* { name: "Joey", age: 28 },
* ];
*
* const nameOfPersonAbove18 = (p: Person) => (p.age <= 18 ? none : some(p.name));
* const nameOfPersonAbove70 = (p: Person) => (p.age <= 70 ? none : some(p.name));
* assert.deepStrictEqual(findLastMap(nameOfPersonAbove18)(persons), some("Joey"));
* assert.deepStrictEqual(findLastMap(nameOfPersonAbove70)(persons), none);
*
* @since 2.0.0
*/
export var findLastMap = RA.findLastMap;
/**
* Returns the index of the last element of the list which matches the predicate.
* It returns an `Option` containing the index or `None` if not found.
*
* @example
* import { findLastIndex } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* interface X {
* readonly a: number
* readonly b: number
* }
* const xs: Array = [{ a: 1, b: 0 }, { a: 1, b: 1 }]
* assert.deepStrictEqual(findLastIndex((x: { readonly a: number }) => x.a === 1)(xs), some(1))
* assert.deepStrictEqual(findLastIndex((x: { readonly a: number }) => x.a === 4)(xs), none)
*
* @since 2.0.0
*/
export var findLastIndex = RA.findLastIndex;
/**
* This function takes an array and makes a new array containing the same elements.
*
* @since 2.0.0
*/
export var copy = function (as) { return as.slice(); };
/**
* Insert an element at the specified index, creating a new array,
* or returning `None` if the index is out of bounds.
*
* @example
* import { insertAt } from 'fp-ts/Array'
* import { some } from 'fp-ts/Option'
*
* assert.deepStrictEqual(insertAt(2, 5)([1, 2, 3, 4]), some([1, 2, 5, 3, 4]))
*
* @since 2.0.0
*/
export var insertAt = function (i, a) {
return function (as) {
return i < 0 || i > as.length ? _.none : _.some(unsafeInsertAt(i, a, as));
};
};
/**
* Change the element at the specified index, creating a new array,
* or returning `None` if the index is out of bounds.
*
* @example
* import { updateAt } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* assert.deepStrictEqual(updateAt(1, 1)([1, 2, 3]), some([1, 1, 3]))
* assert.deepStrictEqual(updateAt(1, 1)([]), none)
*
* @since 2.0.0
*/
export var updateAt = function (i, a) { return modifyAt(i, function () { return a; }); };
/**
* Delete the element at the specified index, creating a new array, or returning `None` if the index is out of bounds.
*
* @example
* import { deleteAt } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* assert.deepStrictEqual(deleteAt(0)([1, 2, 3]), some([2, 3]))
* assert.deepStrictEqual(deleteAt(1)([]), none)
*
* @since 2.0.0
*/
export var deleteAt = function (i) {
return function (as) {
return isOutOfBound(i, as) ? _.none : _.some(unsafeDeleteAt(i, as));
};
};
/**
* Apply a function to the element at the specified index, creating a new array, or returning `None` if the index is out
* of bounds.
*
* @example
* import { modifyAt } from 'fp-ts/Array'
* import { some, none } from 'fp-ts/Option'
*
* const double = (x: number): number => x * 2
* assert.deepStrictEqual(modifyAt(1, double)([1, 2, 3]), some([1, 4, 3]))
* assert.deepStrictEqual(modifyAt(1, double)([]), none)
*
* @since 2.0.0
*/
export var modifyAt = function (i, f) {
return function (as) {
return isOutOfBound(i, as) ? _.none : _.some(unsafeUpdateAt(i, f(as[i]), as));
};
};
/**
* Reverse an array, creating a new array
*
* @example
* import { reverse } from 'fp-ts/Array'
*
* assert.deepStrictEqual(reverse([1, 2, 3]), [3, 2, 1])
*
* @since 2.0.0
*/
export var reverse = function (as) { return (isEmpty(as) ? [] : as.slice().reverse()); };
/**
* Takes an `Array` of `Either` and produces a new `Array` containing
* the values of all the `Right` elements in the same order.
*
* @example
* import { rights } from 'fp-ts/Array'
* import { right, left } from 'fp-ts/Either'
*
* assert.deepStrictEqual(rights([right(1), left('foo'), right(2)]), [1, 2])
*
* @since 2.0.0
*/
export var rights = function (as) {
var r = [];
for (var i = 0; i < as.length; i++) {
var a = as[i];
if (a._tag === 'Right') {
r.push(a.right);
}
}
return r;
};
/**
* Takes an `Array` of `Either` and produces a new `Array` containing
* the values of all the `Left` elements in the same order.
*
* @example
* import { lefts } from 'fp-ts/Array'
* import { left, right } from 'fp-ts/Either'
*
* assert.deepStrictEqual(lefts([right(1), left('foo'), right(2)]), ['foo'])
*
* @since 2.0.0
*/
export var lefts = function (as) {
var r = [];
for (var i = 0; i < as.length; i++) {
var a = as[i];
if (a._tag === 'Left') {
r.push(a.left);
}
}
return r;
};
/**
* Sort the elements of an array in increasing order, creating a new array
*
* @example
* import { sort } from 'fp-ts/Array'
* import * as N from 'fp-ts/number'
*
* assert.deepStrictEqual(sort(N.Ord)([3, 2, 1]), [1, 2, 3])
*
* @since 2.0.0
*/
export var sort = function (O) {
return function (as) {
return as.length <= 1 ? copy(as) : as.slice().sort(O.compare);
};
};
/**
* Apply a function to pairs of elements at the same index in two arrays, collecting the results in a new array. If one
* input array is short, excess elements of the longer array are discarded.
*
* @example
* import { zipWith } from 'fp-ts/Array'
*
* assert.deepStrictEqual(zipWith([1, 2, 3], ['a', 'b', 'c', 'd'], (n, s) => s + n), ['a1', 'b2', 'c3'])
*
* @since 2.0.0
*/
export var zipWith = function (fa, fb, f) {
var fc = [];
var len = Math.min(fa.length, fb.length);
for (var i = 0; i < len; i++) {
fc[i] = f(fa[i], fb[i]);
}
return fc;
};
export function zip(as, bs) {
if (bs === undefined) {
return function (bs) { return zip(bs, as); };
}
return zipWith(as, bs, function (a, b) { return [a, b]; });
}
/**
* The function is reverse of `zip`. Takes an array of pairs and return two corresponding arrays
*
* @example
* import { unzip } from 'fp-ts/Array'
*
* assert.deepStrictEqual(unzip([[1, 'a'], [2, 'b'], [3, 'c']]), [[1, 2, 3], ['a', 'b', 'c']])
*
* @since 2.0.0
*/
export var unzip = function (as) {
var fa = [];
var fb = [];
for (var i = 0; i < as.length; i++) {
fa[i] = as[i][0];
fb[i] = as[i][1];
}
return [fa, fb];
};
/**
* Creates a new `Array`, prepending an element to every member of the input `Array`.
*
* @example
* import { prependAll } from 'fp-ts/Array'
*
* assert.deepStrictEqual(prependAll(9)([1, 2, 3, 4]), [9, 1, 9, 2, 9, 3, 9, 4])
*
* @since 2.10.0
*/
export var prependAll = function (middle) {
var f = NEA.prependAll(middle);
return function (as) { return (isNonEmpty(as) ? f(as) : []); };
};
/**
* Creates a new `Array` placing an element in between members of the input `Array`.
*
* @example
* import { intersperse } from 'fp-ts/Array'
*
* assert.deepStrictEqual(intersperse(9)([1, 2, 3, 4]), [1, 9, 2, 9, 3, 9, 4])
*
* @since 2.9.0
*/
export var intersperse = function (middle) {
var f = NEA.intersperse(middle);
return function (as) { return (isNonEmpty(as) ? f(as) : copy(as)); };
};
/**
* Creates a new `Array` rotating the input `Array` by `n` steps.
*
* @example
* import { rotate } from 'fp-ts/Array'
*
* assert.deepStrictEqual(rotate(2)([1, 2, 3, 4, 5]), [4, 5, 1, 2, 3])
*
* @since 2.0.0
*/
export var rotate = function (n) {
var f = NEA.rotate(n);
return function (as) { return (isNonEmpty(as) ? f(as) : copy(as)); };
};
// TODO: remove non-curried overloading in v3
/**
* Test if a value is a member of an `Array`. Takes a `Eq` as a single
* argument which returns the function to use to search for a value of type `A` in
* an `Array`.
*
* @example
* import { elem } from 'fp-ts/Array'
* import * as N from 'fp-ts/number'
* import { pipe } from 'fp-ts/function'
*
* assert.strictEqual(pipe([1, 2, 3], elem(N.Eq)(2)), true)
* assert.strictEqual(pipe([1, 2, 3], elem(N.Eq)(0)), false)
*
* @since 2.0.0
*/
export var elem = RA.elem;
/**
* Creates a new `Array` removing duplicate elements, keeping the first occurrence of an element,
* based on a `Eq`.
*
* @example
* import { uniq } from 'fp-ts/Array'
* import * as N from 'fp-ts/number'
*
* assert.deepStrictEqual(uniq(N.Eq)([1, 2, 1]), [1, 2])
*
* @since 2.0.0
*/
export var uniq = function (E) {
var f = NEA.uniq(E);
return function (as) { return (isNonEmpty(as) ? f(as) : copy(as)); };
};
/**
* Sort the elements of an array in increasing order, where elements are compared using first `ords[0]`, then `ords[1]`,
* etc...
*
* @example
* import { sortBy } from 'fp-ts/Array'
* import { contramap } from 'fp-ts/Ord'
* import * as S from 'fp-ts/string'
* import * as N from 'fp-ts/number'
* import { pipe } from 'fp-ts/function'
*
* interface Person {
* readonly name: string
* readonly age: number
* }
* const byName = pipe(S.Ord, contramap((p: Person) => p.name))
* const byAge = pipe(N.Ord, contramap((p: Person) => p.age))
*
* const sortByNameByAge = sortBy([byName, byAge])
*
* const persons = [{ name: 'a', age: 1 }, { name: 'b', age: 3 }, { name: 'c', age: 2 }, { name: 'b', age: 2 }]
* assert.deepStrictEqual(sortByNameByAge(persons), [
* { name: 'a', age: 1 },
* { name: 'b', age: 2 },
* { name: 'b', age: 3 },
* { name: 'c', age: 2 }
* ])
*
* @since 2.0.0
*/
export var sortBy = function (ords) {
var f = NEA.sortBy(ords);
return function (as) { return (isNonEmpty(as) ? f(as) : copy(as)); };
};
/**
* A useful recursion pattern for processing an array to produce a new array, often used for "chopping" up the input
* array. Typically chop is called with some function that will consume an initial prefix of the array and produce a
* value and the rest of the array.
*
* @example
* import { Eq } from 'fp-ts/Eq'
* import * as A from 'fp-ts/Array'
* import * as N from 'fp-ts/number'
* import { pipe } from 'fp-ts/function'
*
* const group = (S: Eq): ((as: Array) => Array>) => {
* return A.chop(as => {
* const { init, rest } = pipe(as, A.spanLeft((a: A) => S.equals(a, as[0])))
* return [init, rest]
* })
* }
* assert.deepStrictEqual(group(N.Eq)([1, 1, 2, 3, 3, 4]), [[1, 1], [2], [3, 3], [4]])
*
* @since 2.0.0
*/
export var chop = function (f) {
var g = NEA.chop(f);
return function (as) { return (isNonEmpty(as) ? g(as) : []); };
};
/**
* Splits an `Array` into two pieces, the first piece has max `n` elements.
*
* @example
* import { splitAt } from 'fp-ts/Array'
*
* assert.deepStrictEqual(splitAt(2)([1, 2, 3, 4, 5]), [[1, 2], [3, 4, 5]])
*
* @since 2.0.0
*/
export var splitAt = function (n) {
return function (as) {
return n >= 1 && isNonEmpty(as) ? NEA.splitAt(n)(as) : isEmpty(as) ? [copy(as), []] : [[], copy(as)];
};
};
/**
* Splits an array into length-`n` pieces. The last piece will be shorter if `n` does not evenly divide the length of
* the array. Note that `chunksOf(n)([])` is `[]`, not `[[]]`. This is intentional, and is consistent with a recursive
* definition of `chunksOf`; it satisfies the property that
*
* ```ts
* chunksOf(n)(xs).concat(chunksOf(n)(ys)) == chunksOf(n)(xs.concat(ys)))
* ```
*
* whenever `n` evenly divides the length of `xs`.
*
* @example
* import { chunksOf } from 'fp-ts/Array'
*
* assert.deepStrictEqual(chunksOf(2)([1, 2, 3, 4, 5]), [[1, 2], [3, 4], [5]])
*
* @since 2.0.0
*/
export var chunksOf = function (n) {
var f = NEA.chunksOf(n);
return function (as) { return (isNonEmpty(as) ? f(as) : []); };
};
/**
* @category lifting
* @since 2.11.0
*/
export var fromOptionK = function (f) {
return function () {
var a = [];
for (var _i = 0; _i < arguments.length; _i++) {
a[_i] = arguments[_i];
}
return fromOption(f.apply(void 0, a));
};
};
export function comprehension(input, f, g) {
if (g === void 0) { g = function () { return true; }; }
var go = function (scope, input) {
return isNonEmpty(input)
? pipe(NEA.head(input), chain(function (x) { return go(pipe(scope, append(x)), NEA.tail(input)); }))
: g.apply(void 0, scope) ? [f.apply(void 0, scope)]
: [];
};
return go([], input);
}
/**
* @since 2.11.0
*/
export var concatW = function (second) {
return function (first) {
return isEmpty(first) ? copy(second) : isEmpty(second) ? copy(first) : first.concat(second);
};
};
/**
* @since 2.11.0
*/
export var concat = concatW;
export function union(E) {
var unionE = NEA.union(E);
return function (first, second) {
if (second === undefined) {
var unionE_1 = union(E);
return function (second) { return unionE_1(second, first); };
}
return isNonEmpty(first) && isNonEmpty(second)
? unionE(second)(first)
: isNonEmpty(first)
? copy(first)
: copy(second);
};
}
export function intersection(E) {
var elemE = elem(E);
return function (xs, ys) {
if (ys === undefined) {
var intersectionE_1 = intersection(E);
return function (ys) { return intersectionE_1(ys, xs); };
}
return xs.filter(function (a) { return elemE(a, ys); });
};
}
export function difference(E) {
var elemE = elem(E);
return function (xs, ys) {
if (ys === undefined) {
var differenceE_1 = difference(E);
return function (ys) { return differenceE_1(ys, xs); };
}
return xs.filter(function (a) { return !elemE(a, ys); });
};
}
var _map = function (fa, f) { return pipe(fa, map(f)); };
/* istanbul ignore next */
var _mapWithIndex = function (fa, f) { return pipe(fa, mapWithIndex(f)); };
var _ap = function (fab, fa) { return pipe(fab, ap(fa)); };
var _chain = function (ma, f) { return pipe(ma, chain(f)); };
/* istanbul ignore next */
var _filter = function (fa, predicate) { return pipe(fa, filter(predicate)); };
/* istanbul ignore next */
var _filterMap = function (fa, f) { return pipe(fa, filterMap(f)); };
/* istanbul ignore next */
var _partition = function (fa, predicate) {
return pipe(fa, partition(predicate));
};
/* istanbul ignore next */
var _partitionMap = function (fa, f) { return pipe(fa, partitionMap(f)); };
/* istanbul ignore next */
var _partitionWithIndex = function (fa, predicateWithIndex) { return pipe(fa, partitionWithIndex(predicateWithIndex)); };
/* istanbul ignore next */
var _partitionMapWithIndex = function (fa, f) { return pipe(fa, partitionMapWithIndex(f)); };
/* istanbul ignore next */
var _alt = function (fa, that) { return pipe(fa, alt(that)); };
var _reduce = function (fa, b, f) { return pipe(fa, reduce(b, f)); };
/* istanbul ignore next */
var _foldMap = function (M) {
var foldMapM = foldMap(M);
return function (fa, f) { return pipe(fa, foldMapM(f)); };
};
/* istanbul ignore next */
var _reduceRight = function (fa, b, f) { return pipe(fa, reduceRight(b, f)); };
/* istanbul ignore next */
var _reduceWithIndex = function (fa, b, f) {
return pipe(fa, reduceWithIndex(b, f));
};
/* istanbul ignore next */
var _foldMapWithIndex = function (M) {
var foldMapWithIndexM = foldMapWithIndex(M);
return function (fa, f) { return pipe(fa, foldMapWithIndexM(f)); };
};
/* istanbul ignore next */
var _reduceRightWithIndex = function (fa, b, f) {
return pipe(fa, reduceRightWithIndex(b, f));
};
/* istanbul ignore next */
var _filterMapWithIndex = function (fa, f) { return pipe(fa, filterMapWithIndex(f)); };
/* istanbul ignore next */
var _filterWithIndex = function (fa, predicateWithIndex) { return pipe(fa, filterWithIndex(predicateWithIndex)); };
/* istanbul ignore next */
var _extend = function (fa, f) { return pipe(fa, extend(f)); };
/* istanbul ignore next */
var _traverse = function (F) {
var traverseF = traverse(F);
return function (ta, f) { return pipe(ta, traverseF(f)); };
};
/* istanbul ignore next */
var _traverseWithIndex = function (F) {
var traverseWithIndexF = traverseWithIndex(F);
return function (ta, f) { return pipe(ta, traverseWithIndexF(f)); };
};
var _chainRecDepthFirst = RA._chainRecDepthFirst;
var _chainRecBreadthFirst = RA._chainRecBreadthFirst;
/**
* Given an element of the base type, `of` builds an `Array` containing just that
* element of the base type (this is useful for building a `Monad`).
*
* @example
* import { of } from 'fp-ts/Array'
*
* assert.deepStrictEqual(of("a"), ["a"]);
*
* @category constructors
* @since 2.0.0
*/
export var of = NEA.of;
/**
* Makes an empty `Array`, useful for building a [`Monoid`](#Monoid)
*
* @since 2.7.0
*/
export var zero = function () { return []; };
/**
* `map` can be used to turn functions `(a: A) => B` into functions `(fa: Array) => Array`.
* In practice it applies the base function to each element of the array and collects the
* results in a new array.
*
* @example
* import { map } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* const f = (n: number) => n * 2;
* assert.deepStrictEqual(pipe([1, 2, 3], map(f)), [2, 4, 6]);
*
* @category mapping
* @since 2.0.0
*/
export var map = function (f) { return function (fa) { return fa.map(function (a) { return f(a); }); }; };
/**
* @example
* import { ap, map, of } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* // a curried function with 3 input parameteres
* const f = (s1: string) => (n: number) => (s2: string) => s1 + n + s2;
*
* // let's use `ap` to iterate `f` over an array for each input parameter
* assert.deepStrictEqual(pipe(["a", "b"], map(f), ap([1, 2]), ap(["😀", "😫", "😎"])), [
* "a1😀", "a1😫", "a1😎",
* "a2😀", "a2😫", "a2😎",
* "b1😀", "b1😫", "b1😎",
* "b2😀", "b2😫", "b2😎",
* ]);
*
* // given Array implements the Applicative interface with the `of` method,
* // we can write exactly the same thing in a more symmetric way
* // using `of` on `f` and `ap` on each array in input
* assert.deepStrictEqual(
* pipe(of(f), ap(["a", "b"]), ap([1, 2]), ap(["😀", "😫", "😎"])),
* pipe(["a", "b"], map(f), ap([1, 2]), ap(["😀", "😫", "😎"]))
* );
*
* @since 2.0.0
*/
export var ap = function (fa) { return chain(function (f) { return pipe(fa, map(f)); }); };
/**
* Composes computations in sequence, using the return value of one computation to
* determine the next computation.
*
* In other words it takes a function `f` that produces an array from a single element of
* the base type `A` and returns a new function which applies `f` to each element of the
* input array (like [`map`](#map)) and, instead of returning an array of arrays, concatenates the
* results into a single array (like [`flatten`](#flatten)).
*
* This is the `chain` component of the array `Monad`.
*
* @example
* import { chain, map, replicate } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* const f = (n: number) => replicate(n, `${n}`);
* assert.deepStrictEqual(pipe([1, 2, 3], map(f)), [["1"], ["2", "2"], ["3", "3", "3"]]);
* assert.deepStrictEqual(pipe([1, 2, 3], chain(f)), ["1", "2", "2", "3", "3", "3"]);
*
* @category sequencing
* @since 2.0.0
*/
export var chain = function (f) { return function (ma) {
return pipe(ma, chainWithIndex(function (_, a) { return f(a); }));
}; };
/**
* Takes an array of arrays of `A` and flattens them into an array of `A`
* by concatenating the elements of each array in order.
*
* @example
* import { flatten } from 'fp-ts/Array'
*
* assert.deepStrictEqual(flatten([["a"], ["b", "c"], ["d", "e", "f"]]), ["a", "b", "c", "d", "e", "f"]);
*
* @category sequencing
* @since 2.5.0
*/
export var flatten = /*#__PURE__*/ chain(identity);
/**
* Same as [`map`](#map), but the iterating function takes both the index and the value
* of the element.
*
* @example
* import { mapWithIndex } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* const f = (i: number, s: string) => `${s} - ${i}`;
* assert.deepStrictEqual(pipe(["a", "b", "c"], mapWithIndex(f)), ["a - 0", "b - 1", "c - 2"]);
*
* @category mapping
* @since 2.0.0
*/
export var mapWithIndex = function (f) { return function (fa) {
return fa.map(function (a, i) { return f(i, a); });
}; };
/**
* Maps an array with an iterating function that takes the index and the value of
* each element and returns an `Option`. It keeps only the `Some` values discarding
* the `None`s.
*
* Same as [`filterMap`](#filterMap), but with an iterating function which takes also
* the index as input.
*
* @example
* import { filterMapWithIndex } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
* import { option } from "fp-ts";
*
* const f = (i: number, s: string) => (i % 2 === 1 ? option.some(s.toUpperCase()) : option.none);
* assert.deepStrictEqual(pipe(["a", "no", "neither", "b"], filterMapWithIndex(f)), ["NO", "B"]);
*
* @category filtering
* @since 2.0.0
*/
export var filterMapWithIndex = function (f) {
return function (fa) {
var out = [];
for (var i = 0; i < fa.length; i++) {
var optionB = f(i, fa[i]);
if (_.isSome(optionB)) {
out.push(optionB.value);
}
}
return out;
};
};
/**
* Maps an array with an iterating function that returns an `Option`
* and it keeps only the `Some` values discarding the `None`s.
*
* @example
* import { filterMap } from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
* import { option } from "fp-ts";
*
* const f = (s: string) => s.length === 1 ? option.some(s.toUpperCase()) : option.none;
* assert.deepStrictEqual(pipe(["a", "no", "neither", "b"], filterMap(f)), ["A", "B"]);
*
* @category filtering
* @since 2.0.0
*/
export var filterMap = function (f) {
return filterMapWithIndex(function (_, a) { return f(a); });
};
/**
* Compact an array of `Option`s discarding the `None` values and
* keeping the `Some` values. It returns a new array containing the values of
* the `Some` options.
*
* @example
* import { compact } from 'fp-ts/Array'
* import { option } from "fp-ts";
*
* assert.deepStrictEqual(compact([option.some("a"), option.none, option.some("b")]), ["a", "b"]);
*
* @category filtering
* @since 2.0.0
*/
export var compact = /*#__PURE__*/ filterMap(identity);
/**
* Separate an array of `Either`s into `Left`s and `Right`s, creating two new arrays:
* one containing all the left values and one containing all the right values.
*
* @example
* import { separate } from 'fp-ts/Array'
* import { either } from "fp-ts";
*
* assert.deepStrictEqual(separate([either.right("r1"), either.left("l1"), either.right("r2")]), {
* left: ["l1"],
* right: ["r1", "r2"],
* });
*
* @category filtering
* @since 2.0.0
*/
export var separate = function (fa) {
var left = [];
var right = [];
for (var _i = 0, fa_1 = fa; _i < fa_1.length; _i++) {
var e = fa_1[_i];
if (e._tag === 'Left') {
left.push(e.left);
}
else {
right.push(e.right);
}
}
return separated(left, right);
};
/**
* Given an iterating function that is a `Predicate` or a `Refinement`,
* `filter` creates a new `Array` containing the elements of the original
* `Array` for which the iterating function is `true`.
*
* @example
* import { filter } from 'fp-ts/Array'
* import { isString } from "fp-ts/lib/string";
*
* assert.deepStrictEqual(filter(isString)(["a", 1, {}, "b", 5]), ["a", "b"]);
* assert.deepStrictEqual(filter((x:number) => x > 0)([-3, 1, -2, 5]), [1, 5]);
*
* @category filtering
* @since 2.0.0
*/
export var filter = function (predicate) {
return function (as) {
return as.filter(predicate);
};
};
/**
* Given an iterating function that is a `Predicate` or a `Refinement`,
* `partition` creates two new `Array`s: `right` containing the elements of the original
* `Array` for which the iterating function is `true`, `left` containing the elements
* for which it is false.
*
* @example
* import { partition } from 'fp-ts/Array'
* import { isString } from "fp-ts/lib/string";
*
* assert.deepStrictEqual(partition(isString)(["a", 1, {}, "b", 5]), { left: [1, {}, 5], right: ["a", "b"] });
* assert.deepStrictEqual(partition((x: number) => x > 0)([-3, 1, -2, 5]), { left: [-3, -2], right: [1, 5] });
*
* @category filtering
* @since 2.0.0
*/
export var partition = function (predicate) {
return partitionWithIndex(function (_, a) { return predicate(a); });
};
/**
* Same as [`partition`](#partition), but passing also the index to the iterating function.
*
* @example
* import { partitionWithIndex } from 'fp-ts/Array'
*
* assert.deepStrictEqual(partitionWithIndex((index, x: number) => index < 3 && x > 0)([-2, 5, 6, 7]), {
* left: [-2, 7],
* right: [5, 6],
* });
*
* @category filtering
* @since 2.0.0
*/
export var partitionWithIndex = function (predicateWithIndex) {
return function (as) {
var left = [];
var right = [];
for (var i = 0; i < as.length; i++) {
var b = as[i];
if (predicateWithIndex(i, b)) {
right.push(b);
}
else {
left.push(b);
}
}
return separated(left, right);
};
};
/**
* Given an iterating function that returns an `Either`,
* `partitionMap` applies the iterating function to each element and it creates two `Array`s:
* `right` containing the values of `Right` results, `left` containing the values of `Left` results.
*
* @example
* import { partitionMap } from 'fp-ts/Array'
* import { Either, left, right } from "fp-ts/lib/Either";
*
* const upperIfString = (x: B): Either =>
* typeof x === "string" ? right(x.toUpperCase()) : left(x);
* assert.deepStrictEqual(partitionMap(upperIfString)([-2, "hello", 6, 7, "world"]), {
* left: [-2, 6, 7],
* right: [ 'HELLO', 'WORLD' ],
* });
*
* @category filtering
* @since 2.0.0
*/
export var partitionMap = function (f) { return partitionMapWithIndex(function (_, a) { return f(a); }); };
/**
* Same as [`partitionMap`](#partitionMap), but passing also the index to the iterating function.
*
* @example
* import { partitionMapWithIndex } from 'fp-ts/Array'
* import { Either, left, right } from "fp-ts/lib/Either";
*
* const upperIfStringBefore3 = (index: number, x: B): Either =>
* index < 3 && typeof x === "string" ? right(x.toUpperCase()) : left(x);
* assert.deepStrictEqual(partitionMapWithIndex(upperIfStringBefore3)([-2, "hello", 6, 7, "world"]), {
* left: [-2, 6, 7, "world"],
* right: ["HELLO"],
* });
*
* @category filtering
* @since 2.0.0
*/
export var partitionMapWithIndex = function (f) {
return function (fa) {
var left = [];
var right = [];
for (var i = 0; i < fa.length; i++) {
var e = f(i, fa[i]);
if (e._tag === 'Left') {
left.push(e.left);
}
else {
right.push(e.right);
}
}
return separated(left, right);
};
};
/**
* Less strict version of [`alt`](#alt).
*
* The `W` suffix (short for **W**idening) means that the return types will be merged.
*
* @example
* import * as A from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(
* pipe(
* [1, 2, 3],
* A.altW(() => ['a', 'b'])
* ),
* [1, 2, 3, 'a', 'b']
* )
*
* @category error handling
* @since 2.9.0
*/
export var altW = function (that) {
return function (fa) {
return fa.concat(that());
};
};
/**
* Identifies an associative operation on a type constructor. It is similar to `Semigroup`, except that it applies to
* types of kind `* -> *`.
*
* In case of `Array` concatenates the inputs into a single array.
*
* @example
* import * as A from 'fp-ts/Array'
* import { pipe } from 'fp-ts/function'
*
* assert.deepStrictEqual(
* pipe(
* [1, 2, 3],
* A.alt(() => [4, 5])
* ),
* [1, 2, 3, 4, 5]
* )
*
* @category error handling
* @since 2.0.0
*/
export var alt = altW;
/**
* Same as [`filter`](#filter), but passing also the index to the iterating function.
*
* @example
* import { filterWithIndex } from 'fp-ts/Array';
*
* const f = (index: number, x: number) => x > 0 && index <= 2;
* assert.deepStrictEqual(filterWithIndex(f)([-3, 1, -2, 5]), [1]);
*
* @category filtering
* @since 2.0.0
*/
export var filterWithIndex = function (predicateWithIndex) {
return function (as) {
return as.filter(function (b, i) { return predicateWithIndex(i, b); });
};
};
/**
* Given an iterating function that takes `Array` as input, `extend` returns
* an array containing the results of the iterating function applied to the whole input
* `Array`, then to the input `Array` without the first element, then to the input
* `Array` without the first two elements, etc.
*
* @example
* import { extend } from 'fp-ts/Array'
*
* const f = (a: string[]) => a.join(",");
* assert.deepStrictEqual(extend(f)(["a", "b", "c"]), ["a,b,c", "b,c", "c"]);
*
* @since 2.0.0
*/
export var extend = function (f) { return function (wa) {
return wa.map(function (_, i) { return f(wa.slice(i)); });
}; };
/**
* `duplicate` returns an array containing the whole input `Array`,
* then to the input `Array` dropping the first element, then to the input
* `Array` dropping the first two elements, etc.
*
* @example
* import { duplicate } from 'fp-ts/Array'
*
* assert.deepStrictEqual(duplicate(["a", "b", "c"]), [["a", "b", "c"], ["b", "c"], ["c"]]);
*
* @since 2.0.0
*/
export var duplicate = /*#__PURE__*/ extend(identity);
/**
* Map and fold an `Array`.
* Map the `Array` passing each value to the iterating function.
* Then fold the results using the provided `Monoid`.
*
* @example
* import { foldMap } from 'fp-ts/Array'
*
* const monoid = { concat: (a: string, b: string) => a + b, empty: "" };
* const f = (s: string) => s.toUpperCase()
* assert.deepStrictEqual(foldMap(monoid)(f)(["a", "b", "c"]), "ABC");
*
* @category folding
* @since 2.0.0
*/
export var foldMap = RA.foldMap;
/**
* Same as [`foldMap`](#foldMap) but passing also the index to the iterating function.
*
* @example
* import { foldMapWithIndex } from 'fp-ts/Array'
*
* const monoid = { concat: (a: string, b: string) => a + b, empty: "" };
* const f = (index:number, s: string) => `${s.toUpperCase()}(${index})`
* assert.deepStrictEqual(foldMapWithIndex(monoid)(f)(["a", "b", "c"]), "A(0)B(1)C(2)");
*
* @category folding
* @since 2.0.0
*/
export var foldMapWithIndex = RA.foldMapWithIndex;
/**
* Reduces an `Array`.
*
* `reduce` executes the supplied iterating function on each element of the array,
* in order, passing in the element and the return value from the calculation on the preceding element.
*
* The first time that the iterating function is called there is no "return value of the
* previous calculation", the initial value is used in its place.
*
* @example
* import { reduce } from 'fp-ts/Array'
*
* assert.deepStrictEqual(reduce(5, (acc: number, cur: number) => acc * cur)([2, 3]), 5 * 2 * 3);
*
* @category folding
* @since 2.0.0
*/
export var reduce = RA.reduce;
/**
* Same as [`reduce`](#reduce) but passing also the index to the iterating function.
*
* @example
* import { reduceWithIndex } from 'fp-ts/Array'
*
* const f = (index: number, acc: string, cur: unknown) =>
* acc + (typeof cur === "string" ? cur.toUpperCase() + index : "");
* assert.deepStrictEqual(reduceWithIndex("", f)([2, "a", "b", null]), "A1B2");
*
* @category folding
* @since 2.0.0
*/
export var reduceWithIndex = RA.reduceWithIndex;
/**
* Same as [`reduce`](#reduce) but applied from the end to the start.
*
* *Note*: the iterating function in this case takes the accumulator as the last argument.
*
* @example
* import { reduceRight } from 'fp-ts/Array'
*
* assert.deepStrictEqual(reduceRight("", (cur: string, acc: string) => acc + cur)(["a", "b", "c"]), "cba");
*
* @category folding
* @since 2.0.0
*/
export var reduceRight = RA.reduceRight;
/**
* Same as [`reduceRight`](#reduceRight) but passing also the index to the iterating function.
*
* @example
* import { reduceRightWithIndex } from 'fp-ts/Array'
*
* const f = (index: number, cur: unknown, acc: string) =>
* acc + (typeof cur === "string" ? cur.toUpperCase() + index : "");
* assert.deepStrictEqual(reduceRightWithIndex("", f)([2, "a", "b", null]), "B2A1");
*
* @category folding
* @since 2.0.0
*/
export var reduceRightWithIndex = RA.reduceRightWithIndex;
/**
* Given an iterating function that returns a `HKT` (higher kinded type), `traverse`
* applies the iterating function to each element of the `Array` and then [`sequence`](#sequence)-s
* the results using the provided `Applicative`.
*
* E.g. suppose you have an `Array` and you want to format each element with a function
* that returns a result or an error as `f = (a: A) => Either`, using `traverse`
* you can apply `f` to all elements and directly obtain as a result an `Either>`
* i.e. an `Array` if all the results are `B`, or an `Error` if some of the results
* are `Error`s.
*
* @example
* import { traverse } from 'fp-ts/Array'
* import { Applicative, left, right } from "fp-ts/lib/Either";
*
* const f = (x: unknown) =>
* typeof x === "string" ? right(x.toUpperCase()) : left(new Error("not a string"));
* assert.deepStrictEqual(traverse(Applicative)(f)(["a", "b"]), right(["A", "B"]));
* assert.deepStrictEqual(traverse(Applicative)(f)(["a", 5]), left(new Error("not a string")));
*
* @category traversing
* @since 2.6.3
*/
export var traverse = function (F) {
var traverseWithIndexF = traverseWithIndex(F);
return function (f) { return traverseWithIndexF(function (_, a) { return f(a); }); };
};
/**
* `sequence` takes an `Array` where elements are `HKT` (higher kinded type) and,
* using an applicative of that `HKT`, returns an `HKT` of `Array`.
* E.g. it can turn an `Array>` into an `Either>`.
*
* `sequence` requires an `Applicative` of the `HKT` you are targeting, e.g. to turn an
* `Array>` into an `Either>`, it needs an
* `Applicative` for `Either`, to to turn an `Array