/**
* The `Iterable` module works with any JavaScript value that implements
* `[Symbol.iterator]`, including arrays, strings, generators, sets, and custom
* lazy sequences. It provides constructors, transformations, searches, grouping,
* and folding helpers that can be used without converting to an array first.
*
* **Mental model**
*
* - An `Iterable` creates an `Iterator` when it is consumed.
* - Transformations such as {@link map}, {@link filter}, {@link flatMap},
* {@link take}, and {@link drop} return new iterables and usually do no work
* until the result is iterated.
* - Consumers such as {@link reduce}, {@link size}, {@link head},
* {@link findFirst}, and `Array.from` pull values from an iterator.
* - Constructors such as {@link range}, {@link makeBy}, {@link repeat},
* {@link forever}, and {@link unfold} can represent unbounded sequences.
*
* **Common tasks**
*
* - Create sequences: {@link empty}, {@link of}, {@link range}, {@link makeBy},
* {@link replicate}, {@link unfold}
* - Transform values: {@link map}, {@link flatMap}, {@link flatten},
* {@link filter}, {@link filterMap}
* - Slice and search: {@link take}, {@link drop}, {@link takeWhile},
* {@link findFirst}, {@link findLast}, {@link contains}
* - Combine and group: {@link appendAll}, {@link zipWith}, {@link chunksOf},
* {@link groupBy}, {@link cartesian}
* - Fold or collect: {@link reduce}, {@link scan}, {@link countBy},
* `Array.from`
*
* **Gotchas**
*
* - Laziness depends on the operation. Functions such as {@link size} and
* {@link reduce} consume the iterable immediately.
* - Some JavaScript iterables are single-use iterators. Reusing the same value
* after it has been consumed may produce no elements.
* - Unbounded iterables must be limited before full collection, for example
* with {@link take}.
*
* **Example** (Building a lazy pipeline)
*
* ```ts
* import { Iterable } from "effect"
*
* const naturals = Iterable.range(1)
* const squares = Iterable.map(naturals, (n) => n * n)
* const evenSquares = Iterable.filter(squares, (n) => n % 2 === 0)
* const firstFive = Iterable.take(evenSquares, 5)
*
* console.log(Array.from(firstFive))
* // [4, 16, 36, 64, 100]
* ```
*
* @since 2.0.0
*/
import type { NonEmptyArray } from "./Array.ts";
import type { Option } from "./Option.ts";
import type * as Record from "./Record.ts";
import type { Result } from "./Result.ts";
import type { NoInfer } from "./Types.ts";
/**
* Creates an iterable by applying a function to consecutive integers.
*
* **Details**
*
* The function is called with each index starting from `0`. If no length is
* specified, the iterable is infinite. This is useful for generating
* sequences, patterns, or any indexed data.
*
* **Example** (Generating values by index)
*
* ```ts
* import { Iterable } from "effect"
*
* // Generate first 5 even numbers
* const evens = Iterable.makeBy((n) => n * 2, { length: 5 })
* console.log(Array.from(evens)) // [0, 2, 4, 6, 8]
*
* // Generate squares
* const squares = Iterable.makeBy((n) => n * n, { length: 4 })
* console.log(Array.from(squares)) // [0, 1, 4, 9]
*
* // Infinite sequence (be careful when consuming!)
* const naturals = Iterable.makeBy((n) => n)
* const first10 = Iterable.take(naturals, 10)
* console.log(Array.from(first10)) // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const makeBy: (f: (i: number) => A, options?: {
readonly length?: number;
}) => Iterable;
/**
* Returns an iterable of integers starting at `start` and increasing by `1`.
*
* **Details**
*
* When `end` is provided and `start <= end`, both endpoints are included. When
* `end` is omitted, the iterable is unbounded. When `start > end`, the
* iterable contains only `start`.
*
* **Example** (Creating a range)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(Array.from(Iterable.range(1, 3)), [1, 2, 3])
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const range: (start: number, end?: number) => Iterable;
/**
* Returns a `Iterable` containing a value repeated the specified number of times.
*
* **Details**
*
* `n` is normalized to an integer greater than or equal to `1`.
*
* **Example** (Repeating a value)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(Array.from(Iterable.replicate("a", 3)), ["a", "a", "a"])
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const replicate: {
/**
* Returns a `Iterable` containing a value repeated the specified number of times.
*
* **Details**
*
* `n` is normalized to an integer greater than or equal to `1`.
*
* **Example** (Repeating a value)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(Array.from(Iterable.replicate("a", 3)), ["a", "a", "a"])
* ```
*
* @category constructors
* @since 2.0.0
*/
(n: number): (a: A) => Iterable;
/**
* Returns a `Iterable` containing a value repeated the specified number of times.
*
* **Details**
*
* `n` is normalized to an integer greater than or equal to `1`.
*
* **Example** (Repeating a value)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(Array.from(Iterable.replicate("a", 3)), ["a", "a", "a"])
* ```
*
* @category constructors
* @since 2.0.0
*/
(a: A, n: number): Iterable;
};
/**
* Repeats an iterable `n` times, yielding the full contents of `self` for each
* repetition.
*
* **When to use**
*
* Use to repeat an iterable's contents a specific number of times.
*
* **Details**
*
* The result is lazy. Each repetition obtains a new iterator from `self`.
*
* @see {@link forever} for repeating without an upper bound
* @see {@link replicate} for repeating a single value
* @category constructors
* @since 4.0.0
*/
export declare const repeat: {
/**
* Repeats an iterable `n` times, yielding the full contents of `self` for each
* repetition.
*
* **When to use**
*
* Use to repeat an iterable's contents a specific number of times.
*
* **Details**
*
* The result is lazy. Each repetition obtains a new iterator from `self`.
*
* @see {@link forever} for repeating without an upper bound
* @see {@link replicate} for repeating a single value
* @category constructors
* @since 4.0.0
*/
(n: number): (self: Iterable) => Iterable;
/**
* Repeats an iterable `n` times, yielding the full contents of `self` for each
* repetition.
*
* **When to use**
*
* Use to repeat an iterable's contents a specific number of times.
*
* **Details**
*
* The result is lazy. Each repetition obtains a new iterator from `self`.
*
* @see {@link forever} for repeating without an upper bound
* @see {@link replicate} for repeating a single value
* @category constructors
* @since 4.0.0
*/
(self: Iterable, n: number): Iterable;
};
/**
* Repeats an iterable without an upper bound.
*
* **When to use**
*
* Use to cycle a reusable iterable without an upper bound when a downstream
* consumer controls how many values are taken.
*
* **Gotchas**
*
* The returned iterable is lazy and should usually be bounded with `take` or
* another terminating consumer before materializing it.
*
* @see {@link repeat} for repeating an iterable a specific number of times
* @see {@link take} for bounding the unbounded result before materializing it
*
* @category constructors
* @since 4.0.0
*/
export declare const forever: (self: Iterable) => Iterable;
/**
* Takes a record and returns an Iterable of tuples containing its keys and values.
*
* **Example** (Converting a record to entries)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* const x = { a: 1, b: 2, c: 3 }
* assert.deepStrictEqual(Array.from(Iterable.fromRecord(x)), [["a", 1], ["b", 2], [
* "c",
* 3
* ]])
* ```
*
* @category converting
* @since 2.0.0
*/
export declare const fromRecord: (self: Readonly>) => Iterable<[K, A]>;
/**
* Prepends an element to the front of an `Iterable`, creating a new `Iterable`.
*
* **Example** (Prepending an element)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 3, 4]
* const withOne = Iterable.prepend(numbers, 1)
* console.log(Array.from(withOne)) // [1, 2, 3, 4]
*
* // Works with any iterable
* const letters = "abc"
* const withZ = Iterable.prepend(letters, "z")
* console.log(Array.from(withZ)) // ["z", "a", "b", "c"]
* ```
*
* @category combining
* @since 2.0.0
*/
export declare const prepend: {
/**
* Prepends an element to the front of an `Iterable`, creating a new `Iterable`.
*
* **Example** (Prepending an element)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 3, 4]
* const withOne = Iterable.prepend(numbers, 1)
* console.log(Array.from(withOne)) // [1, 2, 3, 4]
*
* // Works with any iterable
* const letters = "abc"
* const withZ = Iterable.prepend(letters, "z")
* console.log(Array.from(withZ)) // ["z", "a", "b", "c"]
* ```
*
* @category combining
* @since 2.0.0
*/
(head: B): (self: Iterable) => Iterable;
/**
* Prepends an element to the front of an `Iterable`, creating a new `Iterable`.
*
* **Example** (Prepending an element)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 3, 4]
* const withOne = Iterable.prepend(numbers, 1)
* console.log(Array.from(withOne)) // [1, 2, 3, 4]
*
* // Works with any iterable
* const letters = "abc"
* const withZ = Iterable.prepend(letters, "z")
* console.log(Array.from(withZ)) // ["z", "a", "b", "c"]
* ```
*
* @category combining
* @since 2.0.0
*/
(self: Iterable, head: B): Iterable;
};
/**
* Prepends the specified prefix iterable to the beginning of the specified iterable.
*
* **Example** (Prepending another iterable)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(
* Array.from(Iterable.prependAll([1, 2], ["a", "b"])),
* ["a", "b", 1, 2]
* )
* ```
*
* @category combining
* @since 2.0.0
*/
export declare const prependAll: {
/**
* Prepends the specified prefix iterable to the beginning of the specified iterable.
*
* **Example** (Prepending another iterable)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(
* Array.from(Iterable.prependAll([1, 2], ["a", "b"])),
* ["a", "b", 1, 2]
* )
* ```
*
* @category combining
* @since 2.0.0
*/
(that: Iterable): (self: Iterable) => Iterable;
/**
* Prepends the specified prefix iterable to the beginning of the specified iterable.
*
* **Example** (Prepending another iterable)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(
* Array.from(Iterable.prependAll([1, 2], ["a", "b"])),
* ["a", "b", 1, 2]
* )
* ```
*
* @category combining
* @since 2.0.0
*/
(self: Iterable, that: Iterable): Iterable;
};
/**
* Appends an element to the end of an `Iterable`, creating a new `Iterable`.
*
* **When to use**
*
* Use to add one element after all elements of an iterable while keeping the
* result as a lazy `Iterable`.
*
* **Details**
*
* The result yields every element from `self` first, then yields `last` after
* `self` is exhausted.
*
* **Gotchas**
*
* If `self` is infinite or never completes, the appended element is never
* reached.
*
* **Example** (Appending an element)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3]
* const withFour = Iterable.append(numbers, 4)
* console.log(Array.from(withFour)) // [1, 2, 3, 4]
*
* // Chain multiple appends
* const result = Iterable.append(
* Iterable.append([1, 2], 3),
* 4
* )
* console.log(Array.from(result)) // [1, 2, 3, 4]
* ```
*
* @see {@link prepend} for adding one element before the existing elements
* @see {@link appendAll} for appending all elements from another iterable
*
* @category combining
* @since 2.0.0
*/
export declare const append: {
/**
* Appends an element to the end of an `Iterable`, creating a new `Iterable`.
*
* **When to use**
*
* Use to add one element after all elements of an iterable while keeping the
* result as a lazy `Iterable`.
*
* **Details**
*
* The result yields every element from `self` first, then yields `last` after
* `self` is exhausted.
*
* **Gotchas**
*
* If `self` is infinite or never completes, the appended element is never
* reached.
*
* **Example** (Appending an element)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3]
* const withFour = Iterable.append(numbers, 4)
* console.log(Array.from(withFour)) // [1, 2, 3, 4]
*
* // Chain multiple appends
* const result = Iterable.append(
* Iterable.append([1, 2], 3),
* 4
* )
* console.log(Array.from(result)) // [1, 2, 3, 4]
* ```
*
* @see {@link prepend} for adding one element before the existing elements
* @see {@link appendAll} for appending all elements from another iterable
*
* @category combining
* @since 2.0.0
*/
(last: B): (self: Iterable) => Iterable;
/**
* Appends an element to the end of an `Iterable`, creating a new `Iterable`.
*
* **When to use**
*
* Use to add one element after all elements of an iterable while keeping the
* result as a lazy `Iterable`.
*
* **Details**
*
* The result yields every element from `self` first, then yields `last` after
* `self` is exhausted.
*
* **Gotchas**
*
* If `self` is infinite or never completes, the appended element is never
* reached.
*
* **Example** (Appending an element)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3]
* const withFour = Iterable.append(numbers, 4)
* console.log(Array.from(withFour)) // [1, 2, 3, 4]
*
* // Chain multiple appends
* const result = Iterable.append(
* Iterable.append([1, 2], 3),
* 4
* )
* console.log(Array.from(result)) // [1, 2, 3, 4]
* ```
*
* @see {@link prepend} for adding one element before the existing elements
* @see {@link appendAll} for appending all elements from another iterable
*
* @category combining
* @since 2.0.0
*/
(self: Iterable, last: B): Iterable;
};
/**
* Concatenates two iterables, combining their elements.
*
* **When to use**
*
* Use to lazily concatenate two iterables while preserving order, yielding all
* elements from `self` before `that`.
*
* **Details**
*
* The result is lazy. The iterator for `that` is not created or read until
* `self` is exhausted.
*
* **Gotchas**
*
* If `self` is infinite or never completes, `that` is never reached.
*
* **Example** (Concatenating iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* const first = [1, 2, 3]
* const second = [4, 5, 6]
* const combined = Iterable.appendAll(first, second)
* console.log(Array.from(combined)) // [1, 2, 3, 4, 5, 6]
*
* // Works with different iterable types
* const numbers = [1, 2]
* const letters = "abc"
* const mixed = Iterable.appendAll(numbers, letters)
* console.log(Array.from(mixed)) // [1, 2, "a", "b", "c"]
*
* // Lazy evaluation - only consumes what's needed
* const infinite = Iterable.range(1)
* const finite = [0, -1, -2]
* const result = Iterable.take(Iterable.appendAll(finite, infinite), 5)
* console.log(Array.from(result)) // [0, -1, -2, 1, 2]
* ```
*
* @see {@link append} for appending one value instead of another iterable
* @see {@link prependAll} for yielding another iterable before `self`
*
* @category combining
* @since 2.0.0
*/
export declare const appendAll: {
/**
* Concatenates two iterables, combining their elements.
*
* **When to use**
*
* Use to lazily concatenate two iterables while preserving order, yielding all
* elements from `self` before `that`.
*
* **Details**
*
* The result is lazy. The iterator for `that` is not created or read until
* `self` is exhausted.
*
* **Gotchas**
*
* If `self` is infinite or never completes, `that` is never reached.
*
* **Example** (Concatenating iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* const first = [1, 2, 3]
* const second = [4, 5, 6]
* const combined = Iterable.appendAll(first, second)
* console.log(Array.from(combined)) // [1, 2, 3, 4, 5, 6]
*
* // Works with different iterable types
* const numbers = [1, 2]
* const letters = "abc"
* const mixed = Iterable.appendAll(numbers, letters)
* console.log(Array.from(mixed)) // [1, 2, "a", "b", "c"]
*
* // Lazy evaluation - only consumes what's needed
* const infinite = Iterable.range(1)
* const finite = [0, -1, -2]
* const result = Iterable.take(Iterable.appendAll(finite, infinite), 5)
* console.log(Array.from(result)) // [0, -1, -2, 1, 2]
* ```
*
* @see {@link append} for appending one value instead of another iterable
* @see {@link prependAll} for yielding another iterable before `self`
*
* @category combining
* @since 2.0.0
*/
(that: Iterable): (self: Iterable) => Iterable;
/**
* Concatenates two iterables, combining their elements.
*
* **When to use**
*
* Use to lazily concatenate two iterables while preserving order, yielding all
* elements from `self` before `that`.
*
* **Details**
*
* The result is lazy. The iterator for `that` is not created or read until
* `self` is exhausted.
*
* **Gotchas**
*
* If `self` is infinite or never completes, `that` is never reached.
*
* **Example** (Concatenating iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* const first = [1, 2, 3]
* const second = [4, 5, 6]
* const combined = Iterable.appendAll(first, second)
* console.log(Array.from(combined)) // [1, 2, 3, 4, 5, 6]
*
* // Works with different iterable types
* const numbers = [1, 2]
* const letters = "abc"
* const mixed = Iterable.appendAll(numbers, letters)
* console.log(Array.from(mixed)) // [1, 2, "a", "b", "c"]
*
* // Lazy evaluation - only consumes what's needed
* const infinite = Iterable.range(1)
* const finite = [0, -1, -2]
* const result = Iterable.take(Iterable.appendAll(finite, infinite), 5)
* console.log(Array.from(result)) // [0, -1, -2, 1, 2]
* ```
*
* @see {@link append} for appending one value instead of another iterable
* @see {@link prependAll} for yielding another iterable before `self`
*
* @category combining
* @since 2.0.0
*/
(self: Iterable, that: Iterable): Iterable;
};
/**
* Reduces an `Iterable` from the left, keeping all intermediate results instead of only the final result.
*
* **Example** (Tracking running results)
*
* ```ts
* import { Iterable } from "effect"
*
* // Running sum of numbers
* const numbers = [1, 2, 3, 4, 5]
* const runningSum = Iterable.scan(numbers, 0, (acc, n) => acc + n)
* console.log(Array.from(runningSum)) // [0, 1, 3, 6, 10, 15]
*
* // Build strings progressively
* const letters = ["a", "b", "c"]
* const progressive = Iterable.scan(letters, "", (acc, letter) => acc + letter)
* console.log(Array.from(progressive)) // ["", "a", "ab", "abc"]
*
* // Track maximum values seen so far
* const values = [3, 1, 4, 1, 5, 9, 2]
* const runningMax = Iterable.scan(values, -Infinity, Math.max)
* console.log(Array.from(runningMax)) // [-Infinity, 3, 3, 4, 4, 5, 9, 9]
* ```
*
* @category folding
* @since 2.0.0
*/
export declare const scan: {
/**
* Reduces an `Iterable` from the left, keeping all intermediate results instead of only the final result.
*
* **Example** (Tracking running results)
*
* ```ts
* import { Iterable } from "effect"
*
* // Running sum of numbers
* const numbers = [1, 2, 3, 4, 5]
* const runningSum = Iterable.scan(numbers, 0, (acc, n) => acc + n)
* console.log(Array.from(runningSum)) // [0, 1, 3, 6, 10, 15]
*
* // Build strings progressively
* const letters = ["a", "b", "c"]
* const progressive = Iterable.scan(letters, "", (acc, letter) => acc + letter)
* console.log(Array.from(progressive)) // ["", "a", "ab", "abc"]
*
* // Track maximum values seen so far
* const values = [3, 1, 4, 1, 5, 9, 2]
* const runningMax = Iterable.scan(values, -Infinity, Math.max)
* console.log(Array.from(runningMax)) // [-Infinity, 3, 3, 4, 4, 5, 9, 9]
* ```
*
* @category folding
* @since 2.0.0
*/
(b: B, f: (b: B, a: A) => B): (self: Iterable) => Iterable;
/**
* Reduces an `Iterable` from the left, keeping all intermediate results instead of only the final result.
*
* **Example** (Tracking running results)
*
* ```ts
* import { Iterable } from "effect"
*
* // Running sum of numbers
* const numbers = [1, 2, 3, 4, 5]
* const runningSum = Iterable.scan(numbers, 0, (acc, n) => acc + n)
* console.log(Array.from(runningSum)) // [0, 1, 3, 6, 10, 15]
*
* // Build strings progressively
* const letters = ["a", "b", "c"]
* const progressive = Iterable.scan(letters, "", (acc, letter) => acc + letter)
* console.log(Array.from(progressive)) // ["", "a", "ab", "abc"]
*
* // Track maximum values seen so far
* const values = [3, 1, 4, 1, 5, 9, 2]
* const runningMax = Iterable.scan(values, -Infinity, Math.max)
* console.log(Array.from(runningMax)) // [-Infinity, 3, 3, 4, 4, 5, 9, 9]
* ```
*
* @category folding
* @since 2.0.0
*/
(self: Iterable, b: B, f: (b: B, a: A) => B): Iterable;
};
/**
* Checks whether an `Iterable` is empty.
*
* **Example** (Checking for emptiness)
*
* ```ts
* import { Iterable } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(Iterable.isEmpty([]), true)
* assert.deepStrictEqual(Iterable.isEmpty([1, 2, 3]), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isEmpty: (self: Iterable) => self is Iterable;
/**
* Returns the number of elements in a `Iterable`.
*
* **Example** (Counting iterable elements)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* console.log(Iterable.size(numbers)) // 5
*
* const empty = Iterable.empty()
* console.log(Iterable.size(empty)) // 0
*
* // Works with any iterable
* const letters = "hello"
* console.log(Iterable.size(letters)) // 5
*
* // Note: This consumes the entire iterable
* const range = Iterable.range(1, 100)
* console.log(Iterable.size(range)) // 100
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const size: (self: Iterable) => number;
/**
* Gets the first element of a `Iterable` safely, or `None` if the `Iterable` is empty.
*
* **Example** (Getting the first element)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 2, 3]
* console.log(Iterable.head(numbers)) // Option.some(1)
*
* const empty = Iterable.empty()
* console.log(Iterable.head(empty)) // Option.none()
*
* // Safe way to get first element
* const firstEven = Iterable.head(
* Iterable.filter([1, 3, 4, 5], (x) => x % 2 === 0)
* )
* console.log(firstEven) // Option.some(4)
*
* // Use with Option methods
* const doubled = Option.map(Iterable.head([5, 10, 15]), (x) => x * 2)
* console.log(doubled) // Option.some(10)
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const head: (self: Iterable) => Option;
/**
* Gets the first element of a `Iterable`, or throw an error if the `Iterable` is empty.
*
* **Example** (Getting the first element unsafely)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3]
* console.log(Iterable.headUnsafe(numbers)) // 1
*
* const letters = "hello"
* console.log(Iterable.headUnsafe(letters)) // "h"
*
* // Iterable.headUnsafe(Iterable.empty())
* // throws Error: "headUnsafe: empty iterable"
*
* // Use only when you're certain the iterable is non-empty
* const nonEmpty = Iterable.range(1, 10)
* console.log(Iterable.headUnsafe(nonEmpty)) // 1
* ```
*
* @category getters
* @since 4.0.0
*/
export declare const headUnsafe: (self: Iterable) => A;
/**
* Keeps only a max number of elements from the start of an `Iterable`, creating a new `Iterable`.
*
* **Details**
*
* `n` is normalized to a non-negative integer.
*
* **Example** (Taking from the start)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* const firstThree = Iterable.take(numbers, 3)
* console.log(Array.from(firstThree)) // [1, 2, 3]
*
* // Taking more than available returns all elements
* const firstTen = Iterable.take(numbers, 10)
* console.log(Array.from(firstTen)) // [1, 2, 3, 4, 5]
*
* // Taking 0 or negative returns empty
* const none = Iterable.take(numbers, 0)
* console.log(Array.from(none)) // []
*
* // Useful with infinite iterables
* const naturals = Iterable.range(1)
* const firstFive = Iterable.take(naturals, 5)
* console.log(Array.from(firstFive)) // [1, 2, 3, 4, 5]
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const take: {
/**
* Keeps only a max number of elements from the start of an `Iterable`, creating a new `Iterable`.
*
* **Details**
*
* `n` is normalized to a non-negative integer.
*
* **Example** (Taking from the start)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* const firstThree = Iterable.take(numbers, 3)
* console.log(Array.from(firstThree)) // [1, 2, 3]
*
* // Taking more than available returns all elements
* const firstTen = Iterable.take(numbers, 10)
* console.log(Array.from(firstTen)) // [1, 2, 3, 4, 5]
*
* // Taking 0 or negative returns empty
* const none = Iterable.take(numbers, 0)
* console.log(Array.from(none)) // []
*
* // Useful with infinite iterables
* const naturals = Iterable.range(1)
* const firstFive = Iterable.take(naturals, 5)
* console.log(Array.from(firstFive)) // [1, 2, 3, 4, 5]
* ```
*
* @category getters
* @since 2.0.0
*/
(n: number): (self: Iterable) => Iterable;
/**
* Keeps only a max number of elements from the start of an `Iterable`, creating a new `Iterable`.
*
* **Details**
*
* `n` is normalized to a non-negative integer.
*
* **Example** (Taking from the start)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* const firstThree = Iterable.take(numbers, 3)
* console.log(Array.from(firstThree)) // [1, 2, 3]
*
* // Taking more than available returns all elements
* const firstTen = Iterable.take(numbers, 10)
* console.log(Array.from(firstTen)) // [1, 2, 3, 4, 5]
*
* // Taking 0 or negative returns empty
* const none = Iterable.take(numbers, 0)
* console.log(Array.from(none)) // []
*
* // Useful with infinite iterables
* const naturals = Iterable.range(1)
* const firstFive = Iterable.take(naturals, 5)
* console.log(Array.from(firstFive)) // [1, 2, 3, 4, 5]
* ```
*
* @category getters
* @since 2.0.0
*/
(self: Iterable, n: number): Iterable;
};
/**
* Takes the longest initial `Iterable` prefix for which all elements satisfy the
* specified predicate.
*
* **Example** (Taking while a predicate holds)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 4, 6, 8, 3, 10, 12]
* const evenPrefix = Iterable.takeWhile(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evenPrefix)) // [2, 4, 6, 8]
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const firstThreeByIndex = Iterable.takeWhile(letters, (_, i) => i < 3)
* console.log(Array.from(firstThreeByIndex)) // ["a", "b", "c"]
*
* // Stops at first non-matching element
* const mixed = [1, 3, 5, 4, 7, 9]
* const oddPrefix = Iterable.takeWhile(mixed, (x) => x % 2 === 1)
* console.log(Array.from(oddPrefix)) // [1, 3, 5]
*
* // Type refinement
* const values: Array = ["a", "b", "c", 1, "d"]
* const stringPrefix = Iterable.takeWhile(
* values,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(stringPrefix)) // ["a", "b", "c"] (typed as string[])
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const takeWhile: {
/**
* Takes the longest initial `Iterable` prefix for which all elements satisfy the
* specified predicate.
*
* **Example** (Taking while a predicate holds)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 4, 6, 8, 3, 10, 12]
* const evenPrefix = Iterable.takeWhile(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evenPrefix)) // [2, 4, 6, 8]
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const firstThreeByIndex = Iterable.takeWhile(letters, (_, i) => i < 3)
* console.log(Array.from(firstThreeByIndex)) // ["a", "b", "c"]
*
* // Stops at first non-matching element
* const mixed = [1, 3, 5, 4, 7, 9]
* const oddPrefix = Iterable.takeWhile(mixed, (x) => x % 2 === 1)
* console.log(Array.from(oddPrefix)) // [1, 3, 5]
*
* // Type refinement
* const values: Array = ["a", "b", "c", 1, "d"]
* const stringPrefix = Iterable.takeWhile(
* values,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(stringPrefix)) // ["a", "b", "c"] (typed as string[])
* ```
*
* @category getters
* @since 2.0.0
*/
(refinement: (a: NoInfer, i: number) => a is B): (self: Iterable) => Iterable;
/**
* Takes the longest initial `Iterable` prefix for which all elements satisfy the
* specified predicate.
*
* **Example** (Taking while a predicate holds)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 4, 6, 8, 3, 10, 12]
* const evenPrefix = Iterable.takeWhile(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evenPrefix)) // [2, 4, 6, 8]
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const firstThreeByIndex = Iterable.takeWhile(letters, (_, i) => i < 3)
* console.log(Array.from(firstThreeByIndex)) // ["a", "b", "c"]
*
* // Stops at first non-matching element
* const mixed = [1, 3, 5, 4, 7, 9]
* const oddPrefix = Iterable.takeWhile(mixed, (x) => x % 2 === 1)
* console.log(Array.from(oddPrefix)) // [1, 3, 5]
*
* // Type refinement
* const values: Array = ["a", "b", "c", 1, "d"]
* const stringPrefix = Iterable.takeWhile(
* values,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(stringPrefix)) // ["a", "b", "c"] (typed as string[])
* ```
*
* @category getters
* @since 2.0.0
*/
(predicate: (a: NoInfer, i: number) => boolean): (self: Iterable) => Iterable;
/**
* Takes the longest initial `Iterable` prefix for which all elements satisfy the
* specified predicate.
*
* **Example** (Taking while a predicate holds)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 4, 6, 8, 3, 10, 12]
* const evenPrefix = Iterable.takeWhile(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evenPrefix)) // [2, 4, 6, 8]
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const firstThreeByIndex = Iterable.takeWhile(letters, (_, i) => i < 3)
* console.log(Array.from(firstThreeByIndex)) // ["a", "b", "c"]
*
* // Stops at first non-matching element
* const mixed = [1, 3, 5, 4, 7, 9]
* const oddPrefix = Iterable.takeWhile(mixed, (x) => x % 2 === 1)
* console.log(Array.from(oddPrefix)) // [1, 3, 5]
*
* // Type refinement
* const values: Array = ["a", "b", "c", 1, "d"]
* const stringPrefix = Iterable.takeWhile(
* values,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(stringPrefix)) // ["a", "b", "c"] (typed as string[])
* ```
*
* @category getters
* @since 2.0.0
*/
(self: Iterable, refinement: (a: A, i: number) => a is B): Iterable;
/**
* Takes the longest initial `Iterable` prefix for which all elements satisfy the
* specified predicate.
*
* **Example** (Taking while a predicate holds)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [2, 4, 6, 8, 3, 10, 12]
* const evenPrefix = Iterable.takeWhile(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evenPrefix)) // [2, 4, 6, 8]
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const firstThreeByIndex = Iterable.takeWhile(letters, (_, i) => i < 3)
* console.log(Array.from(firstThreeByIndex)) // ["a", "b", "c"]
*
* // Stops at first non-matching element
* const mixed = [1, 3, 5, 4, 7, 9]
* const oddPrefix = Iterable.takeWhile(mixed, (x) => x % 2 === 1)
* console.log(Array.from(oddPrefix)) // [1, 3, 5]
*
* // Type refinement
* const values: Array = ["a", "b", "c", 1, "d"]
* const stringPrefix = Iterable.takeWhile(
* values,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(stringPrefix)) // ["a", "b", "c"] (typed as string[])
* ```
*
* @category getters
* @since 2.0.0
*/
(self: Iterable, predicate: (a: A, i: number) => boolean): Iterable;
};
/**
* Drops a max number of elements from the start of an `Iterable`
*
* **Details**
*
* `n` is normalized to a non-negative integer.
*
* **Example** (Dropping from the start)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* const withoutFirstTwo = Iterable.drop(numbers, 2)
* console.log(Array.from(withoutFirstTwo)) // [3, 4, 5]
*
* // Dropping more than available returns empty
* const withoutFirstTen = Iterable.drop(numbers, 10)
* console.log(Array.from(withoutFirstTen)) // []
*
* // Dropping 0 or negative returns all elements
* const all = Iterable.drop(numbers, 0)
* console.log(Array.from(all)) // [1, 2, 3, 4, 5]
*
* // Combine with take for slicing
* const slice = Iterable.take(Iterable.drop(numbers, 1), 3)
* console.log(Array.from(slice)) // [2, 3, 4]
* ```
*
* @category getters
* @since 2.0.0
*/
export declare const drop: {
/**
* Drops a max number of elements from the start of an `Iterable`
*
* **Details**
*
* `n` is normalized to a non-negative integer.
*
* **Example** (Dropping from the start)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* const withoutFirstTwo = Iterable.drop(numbers, 2)
* console.log(Array.from(withoutFirstTwo)) // [3, 4, 5]
*
* // Dropping more than available returns empty
* const withoutFirstTen = Iterable.drop(numbers, 10)
* console.log(Array.from(withoutFirstTen)) // []
*
* // Dropping 0 or negative returns all elements
* const all = Iterable.drop(numbers, 0)
* console.log(Array.from(all)) // [1, 2, 3, 4, 5]
*
* // Combine with take for slicing
* const slice = Iterable.take(Iterable.drop(numbers, 1), 3)
* console.log(Array.from(slice)) // [2, 3, 4]
* ```
*
* @category getters
* @since 2.0.0
*/
(n: number): (self: Iterable) => Iterable;
/**
* Drops a max number of elements from the start of an `Iterable`
*
* **Details**
*
* `n` is normalized to a non-negative integer.
*
* **Example** (Dropping from the start)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* const withoutFirstTwo = Iterable.drop(numbers, 2)
* console.log(Array.from(withoutFirstTwo)) // [3, 4, 5]
*
* // Dropping more than available returns empty
* const withoutFirstTen = Iterable.drop(numbers, 10)
* console.log(Array.from(withoutFirstTen)) // []
*
* // Dropping 0 or negative returns all elements
* const all = Iterable.drop(numbers, 0)
* console.log(Array.from(all)) // [1, 2, 3, 4, 5]
*
* // Combine with take for slicing
* const slice = Iterable.take(Iterable.drop(numbers, 1), 3)
* console.log(Array.from(slice)) // [2, 3, 4]
* ```
*
* @category getters
* @since 2.0.0
*/
(self: Iterable, n: number): Iterable;
};
/**
* Returns the first element that satisfies the specified
* predicate, or `None` if no such element exists.
*
* **Example** (Finding the first match)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 3, 4, 6, 8]
* const firstEven = Iterable.findFirst(numbers, (x) => x % 2 === 0)
* console.log(firstEven) // Option.some(4)
*
* const firstGreaterThan10 = Iterable.findFirst(numbers, (x) => x > 10)
* console.log(firstGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d"]
* const atEvenIndex = Iterable.findFirst(letters, (_, i) => i % 2 === 0)
* console.log(atEvenIndex) // Option.some("a")
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world"]
* const firstString = Iterable.findFirst(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(firstString) // Option.some("hello")
*
* // Transform during search
* const findSquareRoot = Iterable.findFirst([1, 4, 9, 16], (x) => {
* const sqrt = Math.sqrt(x)
* return Number.isInteger(sqrt) ? Option.some(sqrt) : Option.none()
* })
* console.log(findSquareRoot) // Option.some(1)
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const findFirst: {
/**
* Returns the first element that satisfies the specified
* predicate, or `None` if no such element exists.
*
* **Example** (Finding the first match)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 3, 4, 6, 8]
* const firstEven = Iterable.findFirst(numbers, (x) => x % 2 === 0)
* console.log(firstEven) // Option.some(4)
*
* const firstGreaterThan10 = Iterable.findFirst(numbers, (x) => x > 10)
* console.log(firstGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d"]
* const atEvenIndex = Iterable.findFirst(letters, (_, i) => i % 2 === 0)
* console.log(atEvenIndex) // Option.some("a")
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world"]
* const firstString = Iterable.findFirst(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(firstString) // Option.some("hello")
*
* // Transform during search
* const findSquareRoot = Iterable.findFirst([1, 4, 9, 16], (x) => {
* const sqrt = Math.sqrt(x)
* return Number.isInteger(sqrt) ? Option.some(sqrt) : Option.none()
* })
* console.log(findSquareRoot) // Option.some(1)
* ```
*
* @category elements
* @since 2.0.0
*/
(f: (a: NoInfer, i: number) => Option): (self: Iterable) => Option;
/**
* Returns the first element that satisfies the specified
* predicate, or `None` if no such element exists.
*
* **Example** (Finding the first match)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 3, 4, 6, 8]
* const firstEven = Iterable.findFirst(numbers, (x) => x % 2 === 0)
* console.log(firstEven) // Option.some(4)
*
* const firstGreaterThan10 = Iterable.findFirst(numbers, (x) => x > 10)
* console.log(firstGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d"]
* const atEvenIndex = Iterable.findFirst(letters, (_, i) => i % 2 === 0)
* console.log(atEvenIndex) // Option.some("a")
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world"]
* const firstString = Iterable.findFirst(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(firstString) // Option.some("hello")
*
* // Transform during search
* const findSquareRoot = Iterable.findFirst([1, 4, 9, 16], (x) => {
* const sqrt = Math.sqrt(x)
* return Number.isInteger(sqrt) ? Option.some(sqrt) : Option.none()
* })
* console.log(findSquareRoot) // Option.some(1)
* ```
*
* @category elements
* @since 2.0.0
*/
(refinement: (a: NoInfer, i: number) => a is B): (self: Iterable) => Option;
/**
* Returns the first element that satisfies the specified
* predicate, or `None` if no such element exists.
*
* **Example** (Finding the first match)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 3, 4, 6, 8]
* const firstEven = Iterable.findFirst(numbers, (x) => x % 2 === 0)
* console.log(firstEven) // Option.some(4)
*
* const firstGreaterThan10 = Iterable.findFirst(numbers, (x) => x > 10)
* console.log(firstGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d"]
* const atEvenIndex = Iterable.findFirst(letters, (_, i) => i % 2 === 0)
* console.log(atEvenIndex) // Option.some("a")
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world"]
* const firstString = Iterable.findFirst(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(firstString) // Option.some("hello")
*
* // Transform during search
* const findSquareRoot = Iterable.findFirst([1, 4, 9, 16], (x) => {
* const sqrt = Math.sqrt(x)
* return Number.isInteger(sqrt) ? Option.some(sqrt) : Option.none()
* })
* console.log(findSquareRoot) // Option.some(1)
* ```
*
* @category elements
* @since 2.0.0
*/
(predicate: (a: NoInfer, i: number) => boolean): (self: Iterable) => Option;
/**
* Returns the first element that satisfies the specified
* predicate, or `None` if no such element exists.
*
* **Example** (Finding the first match)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 3, 4, 6, 8]
* const firstEven = Iterable.findFirst(numbers, (x) => x % 2 === 0)
* console.log(firstEven) // Option.some(4)
*
* const firstGreaterThan10 = Iterable.findFirst(numbers, (x) => x > 10)
* console.log(firstGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d"]
* const atEvenIndex = Iterable.findFirst(letters, (_, i) => i % 2 === 0)
* console.log(atEvenIndex) // Option.some("a")
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world"]
* const firstString = Iterable.findFirst(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(firstString) // Option.some("hello")
*
* // Transform during search
* const findSquareRoot = Iterable.findFirst([1, 4, 9, 16], (x) => {
* const sqrt = Math.sqrt(x)
* return Number.isInteger(sqrt) ? Option.some(sqrt) : Option.none()
* })
* console.log(findSquareRoot) // Option.some(1)
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, f: (a: A, i: number) => Option): Option;
/**
* Returns the first element that satisfies the specified
* predicate, or `None` if no such element exists.
*
* **Example** (Finding the first match)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 3, 4, 6, 8]
* const firstEven = Iterable.findFirst(numbers, (x) => x % 2 === 0)
* console.log(firstEven) // Option.some(4)
*
* const firstGreaterThan10 = Iterable.findFirst(numbers, (x) => x > 10)
* console.log(firstGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d"]
* const atEvenIndex = Iterable.findFirst(letters, (_, i) => i % 2 === 0)
* console.log(atEvenIndex) // Option.some("a")
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world"]
* const firstString = Iterable.findFirst(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(firstString) // Option.some("hello")
*
* // Transform during search
* const findSquareRoot = Iterable.findFirst([1, 4, 9, 16], (x) => {
* const sqrt = Math.sqrt(x)
* return Number.isInteger(sqrt) ? Option.some(sqrt) : Option.none()
* })
* console.log(findSquareRoot) // Option.some(1)
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, refinement: (a: A, i: number) => a is B): Option;
/**
* Returns the first element that satisfies the specified
* predicate, or `None` if no such element exists.
*
* **Example** (Finding the first match)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* const numbers = [1, 3, 4, 6, 8]
* const firstEven = Iterable.findFirst(numbers, (x) => x % 2 === 0)
* console.log(firstEven) // Option.some(4)
*
* const firstGreaterThan10 = Iterable.findFirst(numbers, (x) => x > 10)
* console.log(firstGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d"]
* const atEvenIndex = Iterable.findFirst(letters, (_, i) => i % 2 === 0)
* console.log(atEvenIndex) // Option.some("a")
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world"]
* const firstString = Iterable.findFirst(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(firstString) // Option.some("hello")
*
* // Transform during search
* const findSquareRoot = Iterable.findFirst([1, 4, 9, 16], (x) => {
* const sqrt = Math.sqrt(x)
* return Number.isInteger(sqrt) ? Option.some(sqrt) : Option.none()
* })
* console.log(findSquareRoot) // Option.some(1)
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, predicate: (a: A, i: number) => boolean): Option;
};
/**
* Finds the last element for which a predicate holds.
*
* **Example** (Finding the last match)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 4, 6, 8, 2]
* const lastEven = Iterable.findLast(numbers, (x) => x % 2 === 0)
* console.log(lastEven) // Option.some(2)
*
* const lastGreaterThan10 = Iterable.findLast(numbers, (x) => x > 10)
* console.log(lastGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const lastAtEvenIndex = Iterable.findLast(letters, (_, i) => i % 2 === 0)
* console.log(lastAtEvenIndex) // Option.some("e") (index 4)
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world", 3]
* const lastString = Iterable.findLast(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(lastString) // Option.some("world")
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const findLast: {
/**
* Finds the last element for which a predicate holds.
*
* **Example** (Finding the last match)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 4, 6, 8, 2]
* const lastEven = Iterable.findLast(numbers, (x) => x % 2 === 0)
* console.log(lastEven) // Option.some(2)
*
* const lastGreaterThan10 = Iterable.findLast(numbers, (x) => x > 10)
* console.log(lastGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const lastAtEvenIndex = Iterable.findLast(letters, (_, i) => i % 2 === 0)
* console.log(lastAtEvenIndex) // Option.some("e") (index 4)
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world", 3]
* const lastString = Iterable.findLast(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(lastString) // Option.some("world")
* ```
*
* @category elements
* @since 2.0.0
*/
(f: (a: NoInfer, i: number) => Option): (self: Iterable) => Option;
/**
* Finds the last element for which a predicate holds.
*
* **Example** (Finding the last match)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 4, 6, 8, 2]
* const lastEven = Iterable.findLast(numbers, (x) => x % 2 === 0)
* console.log(lastEven) // Option.some(2)
*
* const lastGreaterThan10 = Iterable.findLast(numbers, (x) => x > 10)
* console.log(lastGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const lastAtEvenIndex = Iterable.findLast(letters, (_, i) => i % 2 === 0)
* console.log(lastAtEvenIndex) // Option.some("e") (index 4)
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world", 3]
* const lastString = Iterable.findLast(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(lastString) // Option.some("world")
* ```
*
* @category elements
* @since 2.0.0
*/
(refinement: (a: NoInfer, i: number) => a is B): (self: Iterable) => Option;
/**
* Finds the last element for which a predicate holds.
*
* **Example** (Finding the last match)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 4, 6, 8, 2]
* const lastEven = Iterable.findLast(numbers, (x) => x % 2 === 0)
* console.log(lastEven) // Option.some(2)
*
* const lastGreaterThan10 = Iterable.findLast(numbers, (x) => x > 10)
* console.log(lastGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const lastAtEvenIndex = Iterable.findLast(letters, (_, i) => i % 2 === 0)
* console.log(lastAtEvenIndex) // Option.some("e") (index 4)
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world", 3]
* const lastString = Iterable.findLast(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(lastString) // Option.some("world")
* ```
*
* @category elements
* @since 2.0.0
*/
(predicate: (a: NoInfer, i: number) => boolean): (self: Iterable) => Option;
/**
* Finds the last element for which a predicate holds.
*
* **Example** (Finding the last match)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 4, 6, 8, 2]
* const lastEven = Iterable.findLast(numbers, (x) => x % 2 === 0)
* console.log(lastEven) // Option.some(2)
*
* const lastGreaterThan10 = Iterable.findLast(numbers, (x) => x > 10)
* console.log(lastGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const lastAtEvenIndex = Iterable.findLast(letters, (_, i) => i % 2 === 0)
* console.log(lastAtEvenIndex) // Option.some("e") (index 4)
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world", 3]
* const lastString = Iterable.findLast(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(lastString) // Option.some("world")
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, f: (a: A, i: number) => Option): Option;
/**
* Finds the last element for which a predicate holds.
*
* **Example** (Finding the last match)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 4, 6, 8, 2]
* const lastEven = Iterable.findLast(numbers, (x) => x % 2 === 0)
* console.log(lastEven) // Option.some(2)
*
* const lastGreaterThan10 = Iterable.findLast(numbers, (x) => x > 10)
* console.log(lastGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const lastAtEvenIndex = Iterable.findLast(letters, (_, i) => i % 2 === 0)
* console.log(lastAtEvenIndex) // Option.some("e") (index 4)
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world", 3]
* const lastString = Iterable.findLast(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(lastString) // Option.some("world")
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, refinement: (a: A, i: number) => a is B): Option;
/**
* Finds the last element for which a predicate holds.
*
* **Example** (Finding the last match)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 4, 6, 8, 2]
* const lastEven = Iterable.findLast(numbers, (x) => x % 2 === 0)
* console.log(lastEven) // Option.some(2)
*
* const lastGreaterThan10 = Iterable.findLast(numbers, (x) => x > 10)
* console.log(lastGreaterThan10) // Option.none()
*
* // With index
* const letters = ["a", "b", "c", "d", "e"]
* const lastAtEvenIndex = Iterable.findLast(letters, (_, i) => i % 2 === 0)
* console.log(lastAtEvenIndex) // Option.some("e") (index 4)
*
* // Type refinement
* const mixed: Array = [1, "hello", 2, "world", 3]
* const lastString = Iterable.findLast(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(lastString) // Option.some("world")
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, predicate: (a: A, i: number) => boolean): Option;
};
/**
* Takes two `Iterable`s and returns an `Iterable` of corresponding pairs.
*
* **Example** (Zipping iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3]
* const letters = ["a", "b", "c"]
* const zipped = Iterable.zip(numbers, letters)
* console.log(Array.from(zipped)) // [[1, "a"], [2, "b"], [3, "c"]]
*
* // Different lengths - shorter one determines result length
* const short = [1, 2]
* const long = ["a", "b", "c", "d"]
* const partial = Iterable.zip(short, long)
* console.log(Array.from(partial)) // [[1, "a"], [2, "b"]]
*
* // Works with any iterables
* const range = Iterable.range(1, 3)
* const word = "abc"
* const mixed = Iterable.zip(range, word)
* console.log(Array.from(mixed)) // [[1, "a"], [2, "b"], [3, "c"]]
*
* // Create indexed pairs
* const values = ["apple", "banana", "cherry"]
* const indices = Iterable.range(0, 2)
* const indexed = Iterable.zip(indices, values)
* console.log(Array.from(indexed)) // [[0, "apple"], [1, "banana"], [2, "cherry"]]
* ```
*
* @category zipping
* @since 2.0.0
*/
export declare const zip: {
/**
* Takes two `Iterable`s and returns an `Iterable` of corresponding pairs.
*
* **Example** (Zipping iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3]
* const letters = ["a", "b", "c"]
* const zipped = Iterable.zip(numbers, letters)
* console.log(Array.from(zipped)) // [[1, "a"], [2, "b"], [3, "c"]]
*
* // Different lengths - shorter one determines result length
* const short = [1, 2]
* const long = ["a", "b", "c", "d"]
* const partial = Iterable.zip(short, long)
* console.log(Array.from(partial)) // [[1, "a"], [2, "b"]]
*
* // Works with any iterables
* const range = Iterable.range(1, 3)
* const word = "abc"
* const mixed = Iterable.zip(range, word)
* console.log(Array.from(mixed)) // [[1, "a"], [2, "b"], [3, "c"]]
*
* // Create indexed pairs
* const values = ["apple", "banana", "cherry"]
* const indices = Iterable.range(0, 2)
* const indexed = Iterable.zip(indices, values)
* console.log(Array.from(indexed)) // [[0, "apple"], [1, "banana"], [2, "cherry"]]
* ```
*
* @category zipping
* @since 2.0.0
*/
(that: Iterable): (self: Iterable) => Iterable<[A, B]>;
/**
* Takes two `Iterable`s and returns an `Iterable` of corresponding pairs.
*
* **Example** (Zipping iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3]
* const letters = ["a", "b", "c"]
* const zipped = Iterable.zip(numbers, letters)
* console.log(Array.from(zipped)) // [[1, "a"], [2, "b"], [3, "c"]]
*
* // Different lengths - shorter one determines result length
* const short = [1, 2]
* const long = ["a", "b", "c", "d"]
* const partial = Iterable.zip(short, long)
* console.log(Array.from(partial)) // [[1, "a"], [2, "b"]]
*
* // Works with any iterables
* const range = Iterable.range(1, 3)
* const word = "abc"
* const mixed = Iterable.zip(range, word)
* console.log(Array.from(mixed)) // [[1, "a"], [2, "b"], [3, "c"]]
*
* // Create indexed pairs
* const values = ["apple", "banana", "cherry"]
* const indices = Iterable.range(0, 2)
* const indexed = Iterable.zip(indices, values)
* console.log(Array.from(indexed)) // [[0, "apple"], [1, "banana"], [2, "cherry"]]
* ```
*
* @category zipping
* @since 2.0.0
*/
(self: Iterable, that: Iterable): Iterable<[A, B]>;
};
/**
* Applies a function to pairs of elements at the same index in two `Iterable`s, collecting the results. If one
* input `Iterable` is short, excess elements of the longer `Iterable` are discarded.
*
* **Example** (Zipping with a combining function)
*
* ```ts
* import { Iterable } from "effect"
*
* // Add corresponding elements
* const a = [1, 2, 3, 4]
* const b = [10, 20, 30, 40]
* const sums = Iterable.zipWith(a, b, (x, y) => x + y)
* console.log(Array.from(sums)) // [11, 22, 33, 44]
*
* // Combine strings
* const firstNames = ["John", "Jane", "Bob"]
* const lastNames = ["Doe", "Smith", "Johnson"]
* const fullNames = Iterable.zipWith(
* firstNames,
* lastNames,
* (first, last) => `${first} ${last}`
* )
* console.log(Array.from(fullNames)) // ["John Doe", "Jane Smith", "Bob Johnson"]
*
* // Different lengths - stops at shorter
* const short = [1, 2]
* const long = ["a", "b", "c", "d"]
* const combined = Iterable.zipWith(
* short,
* long,
* (num, letter) => `${num}${letter}`
* )
* console.log(Array.from(combined)) // ["1a", "2b"]
*
* // Complex transformations
* const prices = [10.99, 25.50, 5.00]
* const quantities = [2, 1, 3]
* const totals = Iterable.zipWith(prices, quantities, (price, qty) => {
* return Math.round(price * qty * 100) / 100 // round to 2 decimal places
* })
* console.log(Array.from(totals)) // [21.98, 25.5, 15]
* ```
*
* @category zipping
* @since 2.0.0
*/
export declare const zipWith: {
/**
* Applies a function to pairs of elements at the same index in two `Iterable`s, collecting the results. If one
* input `Iterable` is short, excess elements of the longer `Iterable` are discarded.
*
* **Example** (Zipping with a combining function)
*
* ```ts
* import { Iterable } from "effect"
*
* // Add corresponding elements
* const a = [1, 2, 3, 4]
* const b = [10, 20, 30, 40]
* const sums = Iterable.zipWith(a, b, (x, y) => x + y)
* console.log(Array.from(sums)) // [11, 22, 33, 44]
*
* // Combine strings
* const firstNames = ["John", "Jane", "Bob"]
* const lastNames = ["Doe", "Smith", "Johnson"]
* const fullNames = Iterable.zipWith(
* firstNames,
* lastNames,
* (first, last) => `${first} ${last}`
* )
* console.log(Array.from(fullNames)) // ["John Doe", "Jane Smith", "Bob Johnson"]
*
* // Different lengths - stops at shorter
* const short = [1, 2]
* const long = ["a", "b", "c", "d"]
* const combined = Iterable.zipWith(
* short,
* long,
* (num, letter) => `${num}${letter}`
* )
* console.log(Array.from(combined)) // ["1a", "2b"]
*
* // Complex transformations
* const prices = [10.99, 25.50, 5.00]
* const quantities = [2, 1, 3]
* const totals = Iterable.zipWith(prices, quantities, (price, qty) => {
* return Math.round(price * qty * 100) / 100 // round to 2 decimal places
* })
* console.log(Array.from(totals)) // [21.98, 25.5, 15]
* ```
*
* @category zipping
* @since 2.0.0
*/
(that: Iterable, f: (a: A, b: B) => C): (self: Iterable) => Iterable;
/**
* Applies a function to pairs of elements at the same index in two `Iterable`s, collecting the results. If one
* input `Iterable` is short, excess elements of the longer `Iterable` are discarded.
*
* **Example** (Zipping with a combining function)
*
* ```ts
* import { Iterable } from "effect"
*
* // Add corresponding elements
* const a = [1, 2, 3, 4]
* const b = [10, 20, 30, 40]
* const sums = Iterable.zipWith(a, b, (x, y) => x + y)
* console.log(Array.from(sums)) // [11, 22, 33, 44]
*
* // Combine strings
* const firstNames = ["John", "Jane", "Bob"]
* const lastNames = ["Doe", "Smith", "Johnson"]
* const fullNames = Iterable.zipWith(
* firstNames,
* lastNames,
* (first, last) => `${first} ${last}`
* )
* console.log(Array.from(fullNames)) // ["John Doe", "Jane Smith", "Bob Johnson"]
*
* // Different lengths - stops at shorter
* const short = [1, 2]
* const long = ["a", "b", "c", "d"]
* const combined = Iterable.zipWith(
* short,
* long,
* (num, letter) => `${num}${letter}`
* )
* console.log(Array.from(combined)) // ["1a", "2b"]
*
* // Complex transformations
* const prices = [10.99, 25.50, 5.00]
* const quantities = [2, 1, 3]
* const totals = Iterable.zipWith(prices, quantities, (price, qty) => {
* return Math.round(price * qty * 100) / 100 // round to 2 decimal places
* })
* console.log(Array.from(totals)) // [21.98, 25.5, 15]
* ```
*
* @category zipping
* @since 2.0.0
*/
(self: Iterable, that: Iterable, f: (a: A, b: B) => C): Iterable;
};
/**
* Places a separator between members of an `Iterable`.
*
* **When to use**
*
* Use to lazily insert a separator between adjacent values.
*
* **Details**
*
* If the input is a non-empty array, the result is also a non-empty array.
*
* **Example** (Interspersing separators)
*
* ```ts
* import { Iterable } from "effect"
*
* // Join numbers with separator
* const numbers = [1, 2, 3, 4]
* const withCommas = Iterable.intersperse(numbers, ",")
* console.log(Array.from(withCommas)) // [1, ",", 2, ",", 3, ",", 4]
*
* // Join words with spaces
* const words = ["hello", "world", "from", "effect"]
* const sentence = Iterable.intersperse(words, " ")
* console.log(Array.from(sentence).join("")) // "hello world from effect"
*
* // Empty iterable remains empty
* const empty = Iterable.empty()
* const stillEmpty = Iterable.intersperse(empty, "-")
* console.log(Array.from(stillEmpty)) // []
*
* // Single element has no separators added
* const single = [42]
* const noSeparator = Iterable.intersperse(single, "|")
* console.log(Array.from(noSeparator)) // [42]
*
* // Build CSS-like strings
* const styles = ["color: red", "font-size: 14px", "margin: 10px"]
* const css = Iterable.intersperse(styles, "; ")
* console.log(Array.from(css).join("")) // "color: red; font-size: 14px; margin: 10px"
* ```
*
* @category combining
* @since 2.0.0
*/
export declare const intersperse: {
/**
* Places a separator between members of an `Iterable`.
*
* **When to use**
*
* Use to lazily insert a separator between adjacent values.
*
* **Details**
*
* If the input is a non-empty array, the result is also a non-empty array.
*
* **Example** (Interspersing separators)
*
* ```ts
* import { Iterable } from "effect"
*
* // Join numbers with separator
* const numbers = [1, 2, 3, 4]
* const withCommas = Iterable.intersperse(numbers, ",")
* console.log(Array.from(withCommas)) // [1, ",", 2, ",", 3, ",", 4]
*
* // Join words with spaces
* const words = ["hello", "world", "from", "effect"]
* const sentence = Iterable.intersperse(words, " ")
* console.log(Array.from(sentence).join("")) // "hello world from effect"
*
* // Empty iterable remains empty
* const empty = Iterable.empty()
* const stillEmpty = Iterable.intersperse(empty, "-")
* console.log(Array.from(stillEmpty)) // []
*
* // Single element has no separators added
* const single = [42]
* const noSeparator = Iterable.intersperse(single, "|")
* console.log(Array.from(noSeparator)) // [42]
*
* // Build CSS-like strings
* const styles = ["color: red", "font-size: 14px", "margin: 10px"]
* const css = Iterable.intersperse(styles, "; ")
* console.log(Array.from(css).join("")) // "color: red; font-size: 14px; margin: 10px"
* ```
*
* @category combining
* @since 2.0.0
*/
(middle: B): (self: Iterable) => Iterable;
/**
* Places a separator between members of an `Iterable`.
*
* **When to use**
*
* Use to lazily insert a separator between adjacent values.
*
* **Details**
*
* If the input is a non-empty array, the result is also a non-empty array.
*
* **Example** (Interspersing separators)
*
* ```ts
* import { Iterable } from "effect"
*
* // Join numbers with separator
* const numbers = [1, 2, 3, 4]
* const withCommas = Iterable.intersperse(numbers, ",")
* console.log(Array.from(withCommas)) // [1, ",", 2, ",", 3, ",", 4]
*
* // Join words with spaces
* const words = ["hello", "world", "from", "effect"]
* const sentence = Iterable.intersperse(words, " ")
* console.log(Array.from(sentence).join("")) // "hello world from effect"
*
* // Empty iterable remains empty
* const empty = Iterable.empty()
* const stillEmpty = Iterable.intersperse(empty, "-")
* console.log(Array.from(stillEmpty)) // []
*
* // Single element has no separators added
* const single = [42]
* const noSeparator = Iterable.intersperse(single, "|")
* console.log(Array.from(noSeparator)) // [42]
*
* // Build CSS-like strings
* const styles = ["color: red", "font-size: 14px", "margin: 10px"]
* const css = Iterable.intersperse(styles, "; ")
* console.log(Array.from(css).join("")) // "color: red; font-size: 14px; margin: 10px"
* ```
*
* @category combining
* @since 2.0.0
*/
(self: Iterable, middle: B): Iterable;
};
/**
* Returns a function that checks if an `Iterable` contains a given value using a provided `isEquivalent` function.
*
* **Example** (Checking membership with custom equivalence)
*
* ```ts
* import { Iterable } from "effect"
*
* // Custom equivalence for objects
* const byId = (a: { id: number }, b: { id: number }) => a.id === b.id
* const containsById = Iterable.containsWith(byId)
*
* const users = [{ id: 1 }, { id: 2 }]
* const hasUser1 = containsById(users, { id: 1 })
* console.log(hasUser1) // true (same id)
*
* // Case-insensitive string comparison
* const caseInsensitive = (a: string, b: string) =>
* a.toLowerCase() === b.toLowerCase()
* const containsCaseInsensitive = Iterable.containsWith(caseInsensitive)
*
* const words = ["Hello", "World"]
* const hasHello = containsCaseInsensitive(words, "hello")
* console.log(hasHello) // true
*
* // Approximate number comparison
* const approxEqual = (a: number, b: number) => Math.abs(a - b) < 0.1
* const containsApprox = Iterable.containsWith(approxEqual)
*
* const values = [1.0, 2.0, 3.0]
* const hasAlmostTwo = containsApprox(values, 2.05)
* console.log(hasAlmostTwo) // true
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const containsWith: (isEquivalent: (self: A, that: A) => boolean) => {
(a: A): (self: Iterable) => boolean;
(self: Iterable, a: A): boolean;
};
/**
* Checks whether an iterable contains a value using Effect's default `Equal`
* equivalence.
*
* **Details**
*
* Can be called as `contains(self, value)` or curried as
* `contains(value)(self)`.
*
* **Example** (Checking membership)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* console.log(Iterable.contains(numbers, 3)) // true
* console.log(Iterable.contains(numbers, 6)) // false
*
* const letters = "hello"
* console.log(Iterable.contains(letters, "l")) // true
* console.log(Iterable.contains(letters, "x")) // false
*
* // Works with any iterable
* const range = Iterable.range(1, 100)
* console.log(Iterable.contains(range, 50)) // true
* console.log(Iterable.contains(range, 150)) // false
*
* // Curried version
* const containsThree = Iterable.contains(3)
* console.log(containsThree([1, 2, 3])) // true
* console.log(containsThree([4, 5, 6])) // false
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const contains: {
/**
* Checks whether an iterable contains a value using Effect's default `Equal`
* equivalence.
*
* **Details**
*
* Can be called as `contains(self, value)` or curried as
* `contains(value)(self)`.
*
* **Example** (Checking membership)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* console.log(Iterable.contains(numbers, 3)) // true
* console.log(Iterable.contains(numbers, 6)) // false
*
* const letters = "hello"
* console.log(Iterable.contains(letters, "l")) // true
* console.log(Iterable.contains(letters, "x")) // false
*
* // Works with any iterable
* const range = Iterable.range(1, 100)
* console.log(Iterable.contains(range, 50)) // true
* console.log(Iterable.contains(range, 150)) // false
*
* // Curried version
* const containsThree = Iterable.contains(3)
* console.log(containsThree([1, 2, 3])) // true
* console.log(containsThree([4, 5, 6])) // false
* ```
*
* @category elements
* @since 2.0.0
*/
(a: A): (self: Iterable) => boolean;
/**
* Checks whether an iterable contains a value using Effect's default `Equal`
* equivalence.
*
* **Details**
*
* Can be called as `contains(self, value)` or curried as
* `contains(value)(self)`.
*
* **Example** (Checking membership)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5]
* console.log(Iterable.contains(numbers, 3)) // true
* console.log(Iterable.contains(numbers, 6)) // false
*
* const letters = "hello"
* console.log(Iterable.contains(letters, "l")) // true
* console.log(Iterable.contains(letters, "x")) // false
*
* // Works with any iterable
* const range = Iterable.range(1, 100)
* console.log(Iterable.contains(range, 50)) // true
* console.log(Iterable.contains(range, 150)) // false
*
* // Curried version
* const containsThree = Iterable.contains(3)
* console.log(containsThree([1, 2, 3])) // true
* console.log(containsThree([4, 5, 6])) // false
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, a: A): boolean;
};
/**
* Splits an `Iterable` into length-`n` pieces. The last piece will be shorter if `n` does not evenly divide the length of
* the `Iterable`.
*
* **Example** (Chunking an iterable)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]
* const chunks = Iterable.chunksOf(numbers, 3)
* console.log(Array.from(chunks).map((chunk) => Array.from(chunk)))
* // [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
*
* // Last chunk can be shorter
* const uneven = [1, 2, 3, 4, 5, 6, 7]
* const chunks2 = Iterable.chunksOf(uneven, 3)
* console.log(Array.from(chunks2).map((chunk) => Array.from(chunk)))
* // [[1, 2, 3], [4, 5, 6], [7]]
*
* // Chunk size larger than iterable
* const small = [1, 2]
* const chunks3 = Iterable.chunksOf(small, 5)
* console.log(Array.from(chunks3).map((chunk) => Array.from(chunk)))
* // [[1, 2]]
*
* // Process data in batches
* const data = Iterable.range(1, 100)
* const batches = Iterable.chunksOf(data, 10)
* const batchSums = Iterable.map(
* batches,
* (batch) => Iterable.reduce(batch, 0, (sum, n) => sum + n)
* )
* console.log(Array.from(Iterable.take(batchSums, 3))) // [55, 155, 255]
* ```
*
* @category splitting
* @since 2.0.0
*/
export declare const chunksOf: {
/**
* Splits an `Iterable` into length-`n` pieces. The last piece will be shorter if `n` does not evenly divide the length of
* the `Iterable`.
*
* **Example** (Chunking an iterable)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]
* const chunks = Iterable.chunksOf(numbers, 3)
* console.log(Array.from(chunks).map((chunk) => Array.from(chunk)))
* // [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
*
* // Last chunk can be shorter
* const uneven = [1, 2, 3, 4, 5, 6, 7]
* const chunks2 = Iterable.chunksOf(uneven, 3)
* console.log(Array.from(chunks2).map((chunk) => Array.from(chunk)))
* // [[1, 2, 3], [4, 5, 6], [7]]
*
* // Chunk size larger than iterable
* const small = [1, 2]
* const chunks3 = Iterable.chunksOf(small, 5)
* console.log(Array.from(chunks3).map((chunk) => Array.from(chunk)))
* // [[1, 2]]
*
* // Process data in batches
* const data = Iterable.range(1, 100)
* const batches = Iterable.chunksOf(data, 10)
* const batchSums = Iterable.map(
* batches,
* (batch) => Iterable.reduce(batch, 0, (sum, n) => sum + n)
* )
* console.log(Array.from(Iterable.take(batchSums, 3))) // [55, 155, 255]
* ```
*
* @category splitting
* @since 2.0.0
*/
(n: number): (self: Iterable) => Iterable>;
/**
* Splits an `Iterable` into length-`n` pieces. The last piece will be shorter if `n` does not evenly divide the length of
* the `Iterable`.
*
* **Example** (Chunking an iterable)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]
* const chunks = Iterable.chunksOf(numbers, 3)
* console.log(Array.from(chunks).map((chunk) => Array.from(chunk)))
* // [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
*
* // Last chunk can be shorter
* const uneven = [1, 2, 3, 4, 5, 6, 7]
* const chunks2 = Iterable.chunksOf(uneven, 3)
* console.log(Array.from(chunks2).map((chunk) => Array.from(chunk)))
* // [[1, 2, 3], [4, 5, 6], [7]]
*
* // Chunk size larger than iterable
* const small = [1, 2]
* const chunks3 = Iterable.chunksOf(small, 5)
* console.log(Array.from(chunks3).map((chunk) => Array.from(chunk)))
* // [[1, 2]]
*
* // Process data in batches
* const data = Iterable.range(1, 100)
* const batches = Iterable.chunksOf(data, 10)
* const batchSums = Iterable.map(
* batches,
* (batch) => Iterable.reduce(batch, 0, (sum, n) => sum + n)
* )
* console.log(Array.from(Iterable.take(batchSums, 3))) // [55, 155, 255]
* ```
*
* @category splitting
* @since 2.0.0
*/
(self: Iterable, n: number): Iterable>;
};
/**
* Groups equal, consecutive elements of an `Iterable` into `NonEmptyArray`s using the provided `isEquivalent` function.
*
* **Example** (Grouping consecutive elements with custom equivalence)
*
* ```ts
* import { Iterable } from "effect"
*
* // Group consecutive equal numbers
* const numbers = [1, 1, 2, 2, 2, 3, 1, 1]
* const grouped = Iterable.groupWith(numbers, (a, b) => a === b)
* console.log(Array.from(grouped))
* // [[1, 1], [2, 2, 2], [3], [1, 1]]
*
* // Case-insensitive grouping of strings
* const words = ["Apple", "APPLE", "banana", "Banana", "cherry"]
* const caseInsensitive = (a: string, b: string) =>
* a.toLowerCase() === b.toLowerCase()
* const groupedWords = Iterable.groupWith(words, caseInsensitive)
* console.log(Array.from(groupedWords))
* // [["Apple", "APPLE"], ["banana", "Banana"], ["cherry"]]
*
* // Group by approximate equality
* const floats = [1.1, 1.12, 1.9, 2.01, 2.05, 3.5]
* const approxEqual = (a: number, b: number) => Math.abs(a - b) < 0.2
* const groupedFloats = Iterable.groupWith(floats, approxEqual)
* console.log(Array.from(groupedFloats))
* // [[1.1, 1.12], [1.9, 2.01, 2.05], [3.5]]
*
* // Only groups consecutive elements
* const scattered = [1, 2, 1, 2, 1]
* const scatteredGroups = Iterable.groupWith(scattered, (a, b) => a === b)
* console.log(Array.from(scatteredGroups))
* // [[1], [2], [1], [2], [1]] (no grouping since none are consecutive)
* ```
*
* @category grouping
* @since 2.0.0
*/
export declare const groupWith: {
/**
* Groups equal, consecutive elements of an `Iterable` into `NonEmptyArray`s using the provided `isEquivalent` function.
*
* **Example** (Grouping consecutive elements with custom equivalence)
*
* ```ts
* import { Iterable } from "effect"
*
* // Group consecutive equal numbers
* const numbers = [1, 1, 2, 2, 2, 3, 1, 1]
* const grouped = Iterable.groupWith(numbers, (a, b) => a === b)
* console.log(Array.from(grouped))
* // [[1, 1], [2, 2, 2], [3], [1, 1]]
*
* // Case-insensitive grouping of strings
* const words = ["Apple", "APPLE", "banana", "Banana", "cherry"]
* const caseInsensitive = (a: string, b: string) =>
* a.toLowerCase() === b.toLowerCase()
* const groupedWords = Iterable.groupWith(words, caseInsensitive)
* console.log(Array.from(groupedWords))
* // [["Apple", "APPLE"], ["banana", "Banana"], ["cherry"]]
*
* // Group by approximate equality
* const floats = [1.1, 1.12, 1.9, 2.01, 2.05, 3.5]
* const approxEqual = (a: number, b: number) => Math.abs(a - b) < 0.2
* const groupedFloats = Iterable.groupWith(floats, approxEqual)
* console.log(Array.from(groupedFloats))
* // [[1.1, 1.12], [1.9, 2.01, 2.05], [3.5]]
*
* // Only groups consecutive elements
* const scattered = [1, 2, 1, 2, 1]
* const scatteredGroups = Iterable.groupWith(scattered, (a, b) => a === b)
* console.log(Array.from(scatteredGroups))
* // [[1], [2], [1], [2], [1]] (no grouping since none are consecutive)
* ```
*
* @category grouping
* @since 2.0.0
*/
(isEquivalent: (self: A, that: A) => boolean): (self: Iterable) => Iterable>;
/**
* Groups equal, consecutive elements of an `Iterable` into `NonEmptyArray`s using the provided `isEquivalent` function.
*
* **Example** (Grouping consecutive elements with custom equivalence)
*
* ```ts
* import { Iterable } from "effect"
*
* // Group consecutive equal numbers
* const numbers = [1, 1, 2, 2, 2, 3, 1, 1]
* const grouped = Iterable.groupWith(numbers, (a, b) => a === b)
* console.log(Array.from(grouped))
* // [[1, 1], [2, 2, 2], [3], [1, 1]]
*
* // Case-insensitive grouping of strings
* const words = ["Apple", "APPLE", "banana", "Banana", "cherry"]
* const caseInsensitive = (a: string, b: string) =>
* a.toLowerCase() === b.toLowerCase()
* const groupedWords = Iterable.groupWith(words, caseInsensitive)
* console.log(Array.from(groupedWords))
* // [["Apple", "APPLE"], ["banana", "Banana"], ["cherry"]]
*
* // Group by approximate equality
* const floats = [1.1, 1.12, 1.9, 2.01, 2.05, 3.5]
* const approxEqual = (a: number, b: number) => Math.abs(a - b) < 0.2
* const groupedFloats = Iterable.groupWith(floats, approxEqual)
* console.log(Array.from(groupedFloats))
* // [[1.1, 1.12], [1.9, 2.01, 2.05], [3.5]]
*
* // Only groups consecutive elements
* const scattered = [1, 2, 1, 2, 1]
* const scatteredGroups = Iterable.groupWith(scattered, (a, b) => a === b)
* console.log(Array.from(scatteredGroups))
* // [[1], [2], [1], [2], [1]] (no grouping since none are consecutive)
* ```
*
* @category grouping
* @since 2.0.0
*/
(self: Iterable, isEquivalent: (self: A, that: A) => boolean): Iterable>;
};
/**
* Groups equal, consecutive elements of an `Iterable` into `NonEmptyArray`s.
*
* **Example** (Grouping consecutive elements)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 1, 2, 2, 2, 3, 1, 1]
* const grouped = Iterable.group(numbers)
* console.log(Array.from(grouped))
* // [[1, 1], [2, 2, 2], [3], [1, 1]]
*
* const letters = "aabbccaa"
* const groupedLetters = Iterable.group(letters)
* console.log(Array.from(groupedLetters))
* // [["a", "a"], ["b", "b"], ["c", "c"], ["a", "a"]]
*
* // Works with objects using deep equality
* const objects = [
* { type: "A", value: 1 },
* { type: "A", value: 1 },
* { type: "B", value: 2 },
* { type: "A", value: 1 }
* ]
* const groupedObjects = Iterable.group(objects)
* console.log(Array.from(groupedObjects).length) // 3 groups
* // Note: Only consecutive equal objects are grouped together
* ```
*
* @category grouping
* @since 2.0.0
*/
export declare const group: (self: Iterable) => Iterable>;
/**
* Groups all elements by the string or symbol key returned by `f`.
*
* **Details**
*
* Each property in the returned record contains a non-empty array of elements
* that produced that key. Unlike `group`, matching elements do not need to be
* consecutive.
*
* **Example** (Grouping by a key)
*
* ```ts
* import { Iterable } from "effect"
*
* // Group by string length
* const words = ["a", "bb", "ccc", "dd", "eee", "f"]
* const byLength = Iterable.groupBy(words, (word) => word.length.toString())
* console.log(byLength)
* // { "1": ["a", "f"], "2": ["bb", "dd"], "3": ["ccc", "eee"] }
*
* // Group by first letter
* const names = ["Alice", "Bob", "Charlie", "David", "Anna", "Betty"]
* const byFirstLetter = Iterable.groupBy(names, (name) => name[0])
* console.log(byFirstLetter)
* // { "A": ["Alice", "Anna"], "B": ["Bob", "Betty"], "C": ["Charlie"], "D": ["David"] }
*
* // Group by category
* const items = [
* { name: "apple", category: "fruit" },
* { name: "carrot", category: "vegetable" },
* { name: "banana", category: "fruit" },
* { name: "broccoli", category: "vegetable" }
* ]
* const byCategory = Iterable.groupBy(items, (item) => item.category)
* console.log(byCategory)
* // {
* // "fruit": [{ name: "apple", category: "fruit" }, { name: "banana", category: "fruit" }],
* // "vegetable": [{ name: "carrot", category: "vegetable" }, { name: "broccoli", category: "vegetable" }]
* // }
*
* // Group numbers by even/odd
* const numbers = [1, 2, 3, 4, 5, 6]
* const evenOdd = Iterable.groupBy(numbers, (n) => n % 2 === 0 ? "even" : "odd")
* console.log(evenOdd)
* // { "odd": [1, 3, 5], "even": [2, 4, 6] }
* ```
*
* @category grouping
* @since 2.0.0
*/
export declare const groupBy: {
/**
* Groups all elements by the string or symbol key returned by `f`.
*
* **Details**
*
* Each property in the returned record contains a non-empty array of elements
* that produced that key. Unlike `group`, matching elements do not need to be
* consecutive.
*
* **Example** (Grouping by a key)
*
* ```ts
* import { Iterable } from "effect"
*
* // Group by string length
* const words = ["a", "bb", "ccc", "dd", "eee", "f"]
* const byLength = Iterable.groupBy(words, (word) => word.length.toString())
* console.log(byLength)
* // { "1": ["a", "f"], "2": ["bb", "dd"], "3": ["ccc", "eee"] }
*
* // Group by first letter
* const names = ["Alice", "Bob", "Charlie", "David", "Anna", "Betty"]
* const byFirstLetter = Iterable.groupBy(names, (name) => name[0])
* console.log(byFirstLetter)
* // { "A": ["Alice", "Anna"], "B": ["Bob", "Betty"], "C": ["Charlie"], "D": ["David"] }
*
* // Group by category
* const items = [
* { name: "apple", category: "fruit" },
* { name: "carrot", category: "vegetable" },
* { name: "banana", category: "fruit" },
* { name: "broccoli", category: "vegetable" }
* ]
* const byCategory = Iterable.groupBy(items, (item) => item.category)
* console.log(byCategory)
* // {
* // "fruit": [{ name: "apple", category: "fruit" }, { name: "banana", category: "fruit" }],
* // "vegetable": [{ name: "carrot", category: "vegetable" }, { name: "broccoli", category: "vegetable" }]
* // }
*
* // Group numbers by even/odd
* const numbers = [1, 2, 3, 4, 5, 6]
* const evenOdd = Iterable.groupBy(numbers, (n) => n % 2 === 0 ? "even" : "odd")
* console.log(evenOdd)
* // { "odd": [1, 3, 5], "even": [2, 4, 6] }
* ```
*
* @category grouping
* @since 2.0.0
*/
(f: (a: A) => K): (self: Iterable) => Record, NonEmptyArray>;
/**
* Groups all elements by the string or symbol key returned by `f`.
*
* **Details**
*
* Each property in the returned record contains a non-empty array of elements
* that produced that key. Unlike `group`, matching elements do not need to be
* consecutive.
*
* **Example** (Grouping by a key)
*
* ```ts
* import { Iterable } from "effect"
*
* // Group by string length
* const words = ["a", "bb", "ccc", "dd", "eee", "f"]
* const byLength = Iterable.groupBy(words, (word) => word.length.toString())
* console.log(byLength)
* // { "1": ["a", "f"], "2": ["bb", "dd"], "3": ["ccc", "eee"] }
*
* // Group by first letter
* const names = ["Alice", "Bob", "Charlie", "David", "Anna", "Betty"]
* const byFirstLetter = Iterable.groupBy(names, (name) => name[0])
* console.log(byFirstLetter)
* // { "A": ["Alice", "Anna"], "B": ["Bob", "Betty"], "C": ["Charlie"], "D": ["David"] }
*
* // Group by category
* const items = [
* { name: "apple", category: "fruit" },
* { name: "carrot", category: "vegetable" },
* { name: "banana", category: "fruit" },
* { name: "broccoli", category: "vegetable" }
* ]
* const byCategory = Iterable.groupBy(items, (item) => item.category)
* console.log(byCategory)
* // {
* // "fruit": [{ name: "apple", category: "fruit" }, { name: "banana", category: "fruit" }],
* // "vegetable": [{ name: "carrot", category: "vegetable" }, { name: "broccoli", category: "vegetable" }]
* // }
*
* // Group numbers by even/odd
* const numbers = [1, 2, 3, 4, 5, 6]
* const evenOdd = Iterable.groupBy(numbers, (n) => n % 2 === 0 ? "even" : "odd")
* console.log(evenOdd)
* // { "odd": [1, 3, 5], "even": [2, 4, 6] }
* ```
*
* @category grouping
* @since 2.0.0
*/
(self: Iterable, f: (a: A) => K): Record, NonEmptyArray>;
};
/**
* Creates an empty iterable that yields no elements.
*
* **When to use**
*
* Use as a base case for operations or when you
* need to represent "no data" in a type-safe way.
*
* **Example** (Creating an empty iterable)
*
* ```ts
* import { Iterable } from "effect"
*
* const empty = Iterable.empty()
* console.log(Array.from(empty)) // []
* console.log(Iterable.isEmpty(empty)) // true
*
* // Useful as base case for reductions
* const hasData = true
* const result = hasData
* ? Iterable.range(1, 5)
* : Iterable.empty()
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const empty: () => Iterable;
/**
* Creates an iterable containing a single element.
*
* **When to use**
*
* Use to wrap a single value in an iterable context so it can be combined
* with other iterable operations.
*
* **Example** (Wrapping a single value)
*
* ```ts
* import { Iterable } from "effect"
*
* const single = Iterable.of(42)
* console.log(Array.from(single)) // [42]
*
* // Useful for creating homogeneous sequences
* const sequences = [
* Iterable.of("hello"),
* Iterable.range(1, 3),
* Iterable.empty()
* ]
*
* // Can be used with flatMap for conditional inclusion
* const numbers = [1, 2, 3, 4, 5]
* const evensOnly = Iterable.flatMap(
* numbers,
* (n) => n % 2 === 0 ? Iterable.of(n) : Iterable.empty()
* )
* console.log(Array.from(evensOnly)) // [2, 4]
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const of: (a: A) => Iterable;
/**
* Transforms each element of an iterable using a function.
*
* **Details**
*
* This is one of the most fundamental operations for working with iterables.
* It applies a transformation function to each element, creating a new iterable
* with the transformed values. The operation is lazy - elements are only
* transformed when the iterable is consumed.
*
* **Example** (Mapping elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Transform numbers to their squares
* const numbers = [1, 2, 3, 4, 5]
* const squares = Iterable.map(numbers, (x) => x * x)
* console.log(Array.from(squares)) // [1, 4, 9, 16, 25]
*
* // Use index in transformation
* const indexed = Iterable.map(["a", "b", "c"], (char, i) => `${i}: ${char}`)
* console.log(Array.from(indexed)) // ["0: a", "1: b", "2: c"]
*
* // Chain transformations
* const result = Iterable.map(
* Iterable.map([1, 2, 3], (x) => x * 2),
* (x) => x + 1
* )
* console.log(Array.from(result)) // [3, 5, 7]
* ```
*
* @category mapping
* @since 2.0.0
*/
export declare const map: {
/**
* Transforms each element of an iterable using a function.
*
* **Details**
*
* This is one of the most fundamental operations for working with iterables.
* It applies a transformation function to each element, creating a new iterable
* with the transformed values. The operation is lazy - elements are only
* transformed when the iterable is consumed.
*
* **Example** (Mapping elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Transform numbers to their squares
* const numbers = [1, 2, 3, 4, 5]
* const squares = Iterable.map(numbers, (x) => x * x)
* console.log(Array.from(squares)) // [1, 4, 9, 16, 25]
*
* // Use index in transformation
* const indexed = Iterable.map(["a", "b", "c"], (char, i) => `${i}: ${char}`)
* console.log(Array.from(indexed)) // ["0: a", "1: b", "2: c"]
*
* // Chain transformations
* const result = Iterable.map(
* Iterable.map([1, 2, 3], (x) => x * 2),
* (x) => x + 1
* )
* console.log(Array.from(result)) // [3, 5, 7]
* ```
*
* @category mapping
* @since 2.0.0
*/
(f: (a: NoInfer, i: number) => B): (self: Iterable) => Iterable;
/**
* Transforms each element of an iterable using a function.
*
* **Details**
*
* This is one of the most fundamental operations for working with iterables.
* It applies a transformation function to each element, creating a new iterable
* with the transformed values. The operation is lazy - elements are only
* transformed when the iterable is consumed.
*
* **Example** (Mapping elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Transform numbers to their squares
* const numbers = [1, 2, 3, 4, 5]
* const squares = Iterable.map(numbers, (x) => x * x)
* console.log(Array.from(squares)) // [1, 4, 9, 16, 25]
*
* // Use index in transformation
* const indexed = Iterable.map(["a", "b", "c"], (char, i) => `${i}: ${char}`)
* console.log(Array.from(indexed)) // ["0: a", "1: b", "2: c"]
*
* // Chain transformations
* const result = Iterable.map(
* Iterable.map([1, 2, 3], (x) => x * 2),
* (x) => x + 1
* )
* console.log(Array.from(result)) // [3, 5, 7]
* ```
*
* @category mapping
* @since 2.0.0
*/
(self: Iterable, f: (a: NoInfer, i: number) => B): Iterable;
};
/**
* Applies a function to each element in an Iterable and returns a new Iterable containing the concatenated mapped elements.
*
* **Example** (FlatMapping iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* // Expand each number to a range
* const numbers = [1, 2, 3]
* const expanded = Iterable.flatMap(numbers, (n) => Iterable.range(1, n))
* console.log(Array.from(expanded)) // [1, 1, 2, 1, 2, 3]
*
* // Split strings into characters
* const words = ["hi", "bye"]
* const chars = Iterable.flatMap(words, (word) => word)
* console.log(Array.from(chars)) // ["h", "i", "b", "y", "e"]
*
* // Conditional expansion with empty iterables
* const values = [1, 2, 3, 4, 5]
* const evenMultiples = Iterable.flatMap(
* values,
* (n) => n % 2 === 0 ? [n, n * 2, n * 3] : []
* )
* console.log(Array.from(evenMultiples)) // [2, 4, 6, 4, 8, 12]
*
* // Use index in transformation
* const letters = ["a", "b", "c"]
* const indexed = Iterable.flatMap(
* letters,
* (letter, i) => Iterable.replicate(letter, i + 1)
* )
* console.log(Array.from(indexed)) // ["a", "b", "b", "c", "c", "c"]
* ```
*
* @category sequencing
* @since 2.0.0
*/
export declare const flatMap: {
/**
* Applies a function to each element in an Iterable and returns a new Iterable containing the concatenated mapped elements.
*
* **Example** (FlatMapping iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* // Expand each number to a range
* const numbers = [1, 2, 3]
* const expanded = Iterable.flatMap(numbers, (n) => Iterable.range(1, n))
* console.log(Array.from(expanded)) // [1, 1, 2, 1, 2, 3]
*
* // Split strings into characters
* const words = ["hi", "bye"]
* const chars = Iterable.flatMap(words, (word) => word)
* console.log(Array.from(chars)) // ["h", "i", "b", "y", "e"]
*
* // Conditional expansion with empty iterables
* const values = [1, 2, 3, 4, 5]
* const evenMultiples = Iterable.flatMap(
* values,
* (n) => n % 2 === 0 ? [n, n * 2, n * 3] : []
* )
* console.log(Array.from(evenMultiples)) // [2, 4, 6, 4, 8, 12]
*
* // Use index in transformation
* const letters = ["a", "b", "c"]
* const indexed = Iterable.flatMap(
* letters,
* (letter, i) => Iterable.replicate(letter, i + 1)
* )
* console.log(Array.from(indexed)) // ["a", "b", "b", "c", "c", "c"]
* ```
*
* @category sequencing
* @since 2.0.0
*/
(f: (a: NoInfer, i: number) => Iterable): (self: Iterable) => Iterable;
/**
* Applies a function to each element in an Iterable and returns a new Iterable containing the concatenated mapped elements.
*
* **Example** (FlatMapping iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* // Expand each number to a range
* const numbers = [1, 2, 3]
* const expanded = Iterable.flatMap(numbers, (n) => Iterable.range(1, n))
* console.log(Array.from(expanded)) // [1, 1, 2, 1, 2, 3]
*
* // Split strings into characters
* const words = ["hi", "bye"]
* const chars = Iterable.flatMap(words, (word) => word)
* console.log(Array.from(chars)) // ["h", "i", "b", "y", "e"]
*
* // Conditional expansion with empty iterables
* const values = [1, 2, 3, 4, 5]
* const evenMultiples = Iterable.flatMap(
* values,
* (n) => n % 2 === 0 ? [n, n * 2, n * 3] : []
* )
* console.log(Array.from(evenMultiples)) // [2, 4, 6, 4, 8, 12]
*
* // Use index in transformation
* const letters = ["a", "b", "c"]
* const indexed = Iterable.flatMap(
* letters,
* (letter, i) => Iterable.replicate(letter, i + 1)
* )
* console.log(Array.from(indexed)) // ["a", "b", "b", "c", "c", "c"]
* ```
*
* @category sequencing
* @since 2.0.0
*/
(self: Iterable, f: (a: NoInfer, i: number) => Iterable): Iterable;
};
/**
* Flattens an Iterable of Iterables into a single Iterable
*
* **Example** (Flattening nested iterables)
*
* ```ts
* import { Iterable } from "effect"
*
* // Flatten nested arrays
* const nested = [[1, 2], [3, 4], [5, 6]]
* const flat = Iterable.flatten(nested)
* console.log(Array.from(flat)) // [1, 2, 3, 4, 5, 6]
*
* // Flatten different iterable types
* const mixed: Array> = ["ab", "cd"]
* const flatMixed = Iterable.flatten(mixed)
* console.log(Array.from(flatMixed)) // ["a", "b", "c", "d"]
*
* // Flatten deeply nested (only one level)
* const deepNested = [[[1, 2]], [[3, 4]]]
* const oneLevelFlat = Iterable.flatten(deepNested)
* console.log(Array.from(oneLevelFlat).map((arr) => Array.from(arr)))
* // [[1, 2], [3, 4]] (still contains arrays)
*
* // Empty iterables are handled correctly
* const withEmpty = [[1, 2], [], [3, 4], []]
* const flatWithEmpty = Iterable.flatten(withEmpty)
* console.log(Array.from(flatWithEmpty)) // [1, 2, 3, 4]
* ```
*
* @category sequencing
* @since 2.0.0
*/
export declare const flatten: (self: Iterable>) => Iterable;
/**
* Transforms elements of an iterable using a function that returns a `Result`, keeping only successful values.
*
* **Details**
*
* This combines mapping and filtering in a single operation - the function is applied to each element,
* and only elements that result in `Result.succeed` are included in the result.
*
* **Example** (Filtering and transforming Result values)
*
* ```ts
* import { Iterable, Result } from "effect"
*
* // Parse strings to numbers, keeping only valid ones
* const strings = ["1", "2", "invalid", "4", "not-a-number"]
* const numbers = Iterable.filterMap(strings, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? Result.failVoid : Result.succeed(num)
* })
* console.log(Array.from(numbers)) // [1, 2, 4]
*
* // Extract specific properties from objects
* const users = [
* { name: "Alice", age: 25, email: "alice@example.com" },
* { name: "Bob", age: 17, email: undefined },
* { name: "Charlie", age: 30, email: "charlie@example.com" },
* { name: "David", age: 16, email: undefined }
* ]
* const adultEmails = Iterable.filterMap(
* users,
* (user) =>
* user.age >= 18 && user.email ? Result.succeed(user.email) : Result.failVoid
* )
* console.log(Array.from(adultEmails)) // ["alice@example.com", "charlie@example.com"]
*
* // Use index in transformation
* const items = ["a", "b", "c", "d", "e"]
* const evenIndexItems = Iterable.filterMap(
* items,
* (item, i) => i % 2 === 0 ? Result.succeed(`${i}: ${item}`) : Result.failVoid
* )
* console.log(Array.from(evenIndexItems)) // ["0: a", "2: c", "4: e"]
* ```
*
* @category filtering
* @since 2.0.0
*/
export declare const filterMap: {
/**
* Transforms elements of an iterable using a function that returns a `Result`, keeping only successful values.
*
* **Details**
*
* This combines mapping and filtering in a single operation - the function is applied to each element,
* and only elements that result in `Result.succeed` are included in the result.
*
* **Example** (Filtering and transforming Result values)
*
* ```ts
* import { Iterable, Result } from "effect"
*
* // Parse strings to numbers, keeping only valid ones
* const strings = ["1", "2", "invalid", "4", "not-a-number"]
* const numbers = Iterable.filterMap(strings, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? Result.failVoid : Result.succeed(num)
* })
* console.log(Array.from(numbers)) // [1, 2, 4]
*
* // Extract specific properties from objects
* const users = [
* { name: "Alice", age: 25, email: "alice@example.com" },
* { name: "Bob", age: 17, email: undefined },
* { name: "Charlie", age: 30, email: "charlie@example.com" },
* { name: "David", age: 16, email: undefined }
* ]
* const adultEmails = Iterable.filterMap(
* users,
* (user) =>
* user.age >= 18 && user.email ? Result.succeed(user.email) : Result.failVoid
* )
* console.log(Array.from(adultEmails)) // ["alice@example.com", "charlie@example.com"]
*
* // Use index in transformation
* const items = ["a", "b", "c", "d", "e"]
* const evenIndexItems = Iterable.filterMap(
* items,
* (item, i) => i % 2 === 0 ? Result.succeed(`${i}: ${item}`) : Result.failVoid
* )
* console.log(Array.from(evenIndexItems)) // ["0: a", "2: c", "4: e"]
* ```
*
* @category filtering
* @since 2.0.0
*/
(f: (input: A, i: number) => Result): (self: Iterable) => Iterable;
/**
* Transforms elements of an iterable using a function that returns a `Result`, keeping only successful values.
*
* **Details**
*
* This combines mapping and filtering in a single operation - the function is applied to each element,
* and only elements that result in `Result.succeed` are included in the result.
*
* **Example** (Filtering and transforming Result values)
*
* ```ts
* import { Iterable, Result } from "effect"
*
* // Parse strings to numbers, keeping only valid ones
* const strings = ["1", "2", "invalid", "4", "not-a-number"]
* const numbers = Iterable.filterMap(strings, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? Result.failVoid : Result.succeed(num)
* })
* console.log(Array.from(numbers)) // [1, 2, 4]
*
* // Extract specific properties from objects
* const users = [
* { name: "Alice", age: 25, email: "alice@example.com" },
* { name: "Bob", age: 17, email: undefined },
* { name: "Charlie", age: 30, email: "charlie@example.com" },
* { name: "David", age: 16, email: undefined }
* ]
* const adultEmails = Iterable.filterMap(
* users,
* (user) =>
* user.age >= 18 && user.email ? Result.succeed(user.email) : Result.failVoid
* )
* console.log(Array.from(adultEmails)) // ["alice@example.com", "charlie@example.com"]
*
* // Use index in transformation
* const items = ["a", "b", "c", "d", "e"]
* const evenIndexItems = Iterable.filterMap(
* items,
* (item, i) => i % 2 === 0 ? Result.succeed(`${i}: ${item}`) : Result.failVoid
* )
* console.log(Array.from(evenIndexItems)) // ["0: a", "2: c", "4: e"]
* ```
*
* @category filtering
* @since 2.0.0
*/
(self: Iterable, f: (input: A, i: number) => Result): Iterable;
};
/**
* Transforms all elements of the `Iterable` for as long as the specified function succeeds.
*
* **Example** (Filtering and transforming until failure)
*
* ```ts
* import { Iterable, Result } from "effect"
*
* // Parse numbers until we hit an invalid one
* const strings = ["1", "2", "3", "invalid", "4", "5"]
* const numbers = Iterable.filterMapWhile(strings, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? Result.failVoid : Result.succeed(num)
* })
* console.log(Array.from(numbers)) // [1, 2, 3] (stops at "invalid")
*
* // Take elements while they meet a condition and transform them
* const values = [2, 4, 6, 7, 8, 10]
* const doubledEvens = Iterable.filterMapWhile(
* values,
* (n) => n % 2 === 0 ? Result.succeed(n * 2) : Result.failVoid
* )
* console.log(Array.from(doubledEvens)) // [4, 8, 12] (stops at 7)
*
* // Process with index until condition fails
* const letters = ["a", "b", "c", "d", "e"]
* const indexedUntilC = Iterable.filterMapWhile(
* letters,
* (letter, i) => letter !== "c" ? Result.succeed(`${i}: ${letter}`) : Result.failVoid
* )
* console.log(Array.from(indexedUntilC)) // ["0: a", "1: b"] (stops at "c")
* ```
*
* @category filtering
* @since 2.0.0
*/
export declare const filterMapWhile: {
/**
* Transforms all elements of the `Iterable` for as long as the specified function succeeds.
*
* **Example** (Filtering and transforming until failure)
*
* ```ts
* import { Iterable, Result } from "effect"
*
* // Parse numbers until we hit an invalid one
* const strings = ["1", "2", "3", "invalid", "4", "5"]
* const numbers = Iterable.filterMapWhile(strings, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? Result.failVoid : Result.succeed(num)
* })
* console.log(Array.from(numbers)) // [1, 2, 3] (stops at "invalid")
*
* // Take elements while they meet a condition and transform them
* const values = [2, 4, 6, 7, 8, 10]
* const doubledEvens = Iterable.filterMapWhile(
* values,
* (n) => n % 2 === 0 ? Result.succeed(n * 2) : Result.failVoid
* )
* console.log(Array.from(doubledEvens)) // [4, 8, 12] (stops at 7)
*
* // Process with index until condition fails
* const letters = ["a", "b", "c", "d", "e"]
* const indexedUntilC = Iterable.filterMapWhile(
* letters,
* (letter, i) => letter !== "c" ? Result.succeed(`${i}: ${letter}`) : Result.failVoid
* )
* console.log(Array.from(indexedUntilC)) // ["0: a", "1: b"] (stops at "c")
* ```
*
* @category filtering
* @since 2.0.0
*/
(f: (input: A, i: number) => Result): (self: Iterable) => Iterable;
/**
* Transforms all elements of the `Iterable` for as long as the specified function succeeds.
*
* **Example** (Filtering and transforming until failure)
*
* ```ts
* import { Iterable, Result } from "effect"
*
* // Parse numbers until we hit an invalid one
* const strings = ["1", "2", "3", "invalid", "4", "5"]
* const numbers = Iterable.filterMapWhile(strings, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? Result.failVoid : Result.succeed(num)
* })
* console.log(Array.from(numbers)) // [1, 2, 3] (stops at "invalid")
*
* // Take elements while they meet a condition and transform them
* const values = [2, 4, 6, 7, 8, 10]
* const doubledEvens = Iterable.filterMapWhile(
* values,
* (n) => n % 2 === 0 ? Result.succeed(n * 2) : Result.failVoid
* )
* console.log(Array.from(doubledEvens)) // [4, 8, 12] (stops at 7)
*
* // Process with index until condition fails
* const letters = ["a", "b", "c", "d", "e"]
* const indexedUntilC = Iterable.filterMapWhile(
* letters,
* (letter, i) => letter !== "c" ? Result.succeed(`${i}: ${letter}`) : Result.failVoid
* )
* console.log(Array.from(indexedUntilC)) // ["0: a", "1: b"] (stops at "c")
* ```
*
* @category filtering
* @since 2.0.0
*/
(self: Iterable, f: (input: A, i: number) => Result): Iterable;
};
/**
* Retrieves the `Some` values from an `Iterable` of `Option`s.
*
* **Example** (Extracting Some values)
*
* ```ts
* import { Iterable, Option } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(
* Array.from(
* Iterable.getSomes([Option.some(1), Option.none(), Option.some(2)])
* ),
* [1, 2]
* )
* ```
*
* @category filtering
* @since 2.0.0
*/
export declare const getSomes: (self: Iterable>) => Iterable;
/**
* Returns a lazy iterable containing the failure values from an iterable of
* `Result`s, skipping successful results.
*
* **Example** (Extracting failures)
*
* ```ts
* import { Iterable, Result } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(
* Array.from(
* Iterable.getFailures([
* Result.succeed(1),
* Result.fail("err"),
* Result.succeed(2)
* ])
* ),
* ["err"]
* )
* ```
*
* @category filtering
* @since 4.0.0
*/
export declare const getFailures: (self: Iterable>) => Iterable;
/**
* Returns a lazy iterable containing the success values from an iterable of
* `Result`s, skipping failed results.
*
* **Example** (Extracting successes)
*
* ```ts
* import { Iterable, Result } from "effect"
* import * as assert from "node:assert"
*
* assert.deepStrictEqual(
* Array.from(
* Iterable.getSuccesses([
* Result.succeed(1),
* Result.fail("err"),
* Result.succeed(2)
* ])
* ),
* [1, 2]
* )
* ```
*
* @category filtering
* @since 4.0.0
*/
export declare const getSuccesses: (self: Iterable>) => Iterable;
/**
* Filters an iterable to only include elements that match a predicate.
*
* **Details**
*
* This function creates a new iterable containing only the elements for which
* the predicate function returns true. Like map, this operation is lazy and
* elements are only tested when the iterable is consumed.
*
* **Example** (Filtering elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Filter even numbers
* const numbers = [1, 2, 3, 4, 5, 6]
* const evens = Iterable.filter(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evens)) // [2, 4, 6]
*
* // Filter with index
* const items = ["a", "b", "c", "d"]
* const oddPositions = Iterable.filter(items, (_, i) => i % 2 === 1)
* console.log(Array.from(oddPositions)) // ["b", "d"]
*
* // Type refinement
* const mixed: Array = ["hello", 42, "world", 100]
* const onlyStrings = Iterable.filter(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(onlyStrings)) // ["hello", "world"] (typed as string[])
*
* // Combine with map
* const processed = Iterable.map(
* Iterable.filter([1, 2, 3, 4, 5], (x) => x > 2),
* (x) => x * 10
* )
* console.log(Array.from(processed)) // [30, 40, 50]
* ```
*
* @category filtering
* @since 2.0.0
*/
export declare const filter: {
/**
* Filters an iterable to only include elements that match a predicate.
*
* **Details**
*
* This function creates a new iterable containing only the elements for which
* the predicate function returns true. Like map, this operation is lazy and
* elements are only tested when the iterable is consumed.
*
* **Example** (Filtering elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Filter even numbers
* const numbers = [1, 2, 3, 4, 5, 6]
* const evens = Iterable.filter(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evens)) // [2, 4, 6]
*
* // Filter with index
* const items = ["a", "b", "c", "d"]
* const oddPositions = Iterable.filter(items, (_, i) => i % 2 === 1)
* console.log(Array.from(oddPositions)) // ["b", "d"]
*
* // Type refinement
* const mixed: Array = ["hello", 42, "world", 100]
* const onlyStrings = Iterable.filter(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(onlyStrings)) // ["hello", "world"] (typed as string[])
*
* // Combine with map
* const processed = Iterable.map(
* Iterable.filter([1, 2, 3, 4, 5], (x) => x > 2),
* (x) => x * 10
* )
* console.log(Array.from(processed)) // [30, 40, 50]
* ```
*
* @category filtering
* @since 2.0.0
*/
(refinement: (a: NoInfer, i: number) => a is B): (self: Iterable) => Iterable;
/**
* Filters an iterable to only include elements that match a predicate.
*
* **Details**
*
* This function creates a new iterable containing only the elements for which
* the predicate function returns true. Like map, this operation is lazy and
* elements are only tested when the iterable is consumed.
*
* **Example** (Filtering elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Filter even numbers
* const numbers = [1, 2, 3, 4, 5, 6]
* const evens = Iterable.filter(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evens)) // [2, 4, 6]
*
* // Filter with index
* const items = ["a", "b", "c", "d"]
* const oddPositions = Iterable.filter(items, (_, i) => i % 2 === 1)
* console.log(Array.from(oddPositions)) // ["b", "d"]
*
* // Type refinement
* const mixed: Array = ["hello", 42, "world", 100]
* const onlyStrings = Iterable.filter(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(onlyStrings)) // ["hello", "world"] (typed as string[])
*
* // Combine with map
* const processed = Iterable.map(
* Iterable.filter([1, 2, 3, 4, 5], (x) => x > 2),
* (x) => x * 10
* )
* console.log(Array.from(processed)) // [30, 40, 50]
* ```
*
* @category filtering
* @since 2.0.0
*/
(predicate: (a: NoInfer, i: number) => boolean): (self: Iterable) => Iterable;
/**
* Filters an iterable to only include elements that match a predicate.
*
* **Details**
*
* This function creates a new iterable containing only the elements for which
* the predicate function returns true. Like map, this operation is lazy and
* elements are only tested when the iterable is consumed.
*
* **Example** (Filtering elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Filter even numbers
* const numbers = [1, 2, 3, 4, 5, 6]
* const evens = Iterable.filter(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evens)) // [2, 4, 6]
*
* // Filter with index
* const items = ["a", "b", "c", "d"]
* const oddPositions = Iterable.filter(items, (_, i) => i % 2 === 1)
* console.log(Array.from(oddPositions)) // ["b", "d"]
*
* // Type refinement
* const mixed: Array = ["hello", 42, "world", 100]
* const onlyStrings = Iterable.filter(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(onlyStrings)) // ["hello", "world"] (typed as string[])
*
* // Combine with map
* const processed = Iterable.map(
* Iterable.filter([1, 2, 3, 4, 5], (x) => x > 2),
* (x) => x * 10
* )
* console.log(Array.from(processed)) // [30, 40, 50]
* ```
*
* @category filtering
* @since 2.0.0
*/
(self: Iterable, refinement: (a: A, i: number) => a is B): Iterable;
/**
* Filters an iterable to only include elements that match a predicate.
*
* **Details**
*
* This function creates a new iterable containing only the elements for which
* the predicate function returns true. Like map, this operation is lazy and
* elements are only tested when the iterable is consumed.
*
* **Example** (Filtering elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Filter even numbers
* const numbers = [1, 2, 3, 4, 5, 6]
* const evens = Iterable.filter(numbers, (x) => x % 2 === 0)
* console.log(Array.from(evens)) // [2, 4, 6]
*
* // Filter with index
* const items = ["a", "b", "c", "d"]
* const oddPositions = Iterable.filter(items, (_, i) => i % 2 === 1)
* console.log(Array.from(oddPositions)) // ["b", "d"]
*
* // Type refinement
* const mixed: Array = ["hello", 42, "world", 100]
* const onlyStrings = Iterable.filter(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(Array.from(onlyStrings)) // ["hello", "world"] (typed as string[])
*
* // Combine with map
* const processed = Iterable.map(
* Iterable.filter([1, 2, 3, 4, 5], (x) => x > 2),
* (x) => x * 10
* )
* console.log(Array.from(processed)) // [30, 40, 50]
* ```
*
* @category filtering
* @since 2.0.0
*/
(self: Iterable, predicate: (a: A, i: number) => boolean): Iterable;
};
/**
* Transforms elements using a function that may return null or undefined, filtering out the null/undefined results.
*
* **When to use**
*
* Use when working with APIs or functions that return nullable values,
* providing a clean way to filter out null or undefined while transforming.
*
* **Example** (FlatMapping nullable results)
*
* ```ts
* import { Iterable } from "effect"
*
* // Extract valid elements from nullable function results
* const data = ["1", "2", "invalid", "4"]
* const parsed = Iterable.flatMapNullishOr(data, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? null : num * 2
* })
* console.log(Array.from(parsed)) // [2, 4, 8]
*
* // Safe property access
* const objects = [
* { nested: { value: 10 } },
* { nested: null },
* { nested: { value: 20 } },
* {}
* ]
* const values = Iterable.flatMapNullishOr(objects, (obj) => obj.nested?.value)
* console.log(Array.from(values)) // [10, 20]
*
* // Working with Map.get (returns undefined for missing keys)
* const map = new Map([
* ["a", 1],
* ["b", 2],
* ["c", 3]
* ])
* const keys = ["a", "x", "b", "y", "c"]
* const foundValues = Iterable.flatMapNullishOr(keys, (key) => map.get(key))
* console.log(Array.from(foundValues)) // [1, 2, 3]
* ```
*
* @category sequencing
* @since 4.0.0
*/
export declare const flatMapNullishOr: {
/**
* Transforms elements using a function that may return null or undefined, filtering out the null/undefined results.
*
* **When to use**
*
* Use when working with APIs or functions that return nullable values,
* providing a clean way to filter out null or undefined while transforming.
*
* **Example** (FlatMapping nullable results)
*
* ```ts
* import { Iterable } from "effect"
*
* // Extract valid elements from nullable function results
* const data = ["1", "2", "invalid", "4"]
* const parsed = Iterable.flatMapNullishOr(data, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? null : num * 2
* })
* console.log(Array.from(parsed)) // [2, 4, 8]
*
* // Safe property access
* const objects = [
* { nested: { value: 10 } },
* { nested: null },
* { nested: { value: 20 } },
* {}
* ]
* const values = Iterable.flatMapNullishOr(objects, (obj) => obj.nested?.value)
* console.log(Array.from(values)) // [10, 20]
*
* // Working with Map.get (returns undefined for missing keys)
* const map = new Map([
* ["a", 1],
* ["b", 2],
* ["c", 3]
* ])
* const keys = ["a", "x", "b", "y", "c"]
* const foundValues = Iterable.flatMapNullishOr(keys, (key) => map.get(key))
* console.log(Array.from(foundValues)) // [1, 2, 3]
* ```
*
* @category sequencing
* @since 4.0.0
*/
(f: (a: A) => B): (self: Iterable) => Iterable>;
/**
* Transforms elements using a function that may return null or undefined, filtering out the null/undefined results.
*
* **When to use**
*
* Use when working with APIs or functions that return nullable values,
* providing a clean way to filter out null or undefined while transforming.
*
* **Example** (FlatMapping nullable results)
*
* ```ts
* import { Iterable } from "effect"
*
* // Extract valid elements from nullable function results
* const data = ["1", "2", "invalid", "4"]
* const parsed = Iterable.flatMapNullishOr(data, (s) => {
* const num = parseInt(s)
* return isNaN(num) ? null : num * 2
* })
* console.log(Array.from(parsed)) // [2, 4, 8]
*
* // Safe property access
* const objects = [
* { nested: { value: 10 } },
* { nested: null },
* { nested: { value: 20 } },
* {}
* ]
* const values = Iterable.flatMapNullishOr(objects, (obj) => obj.nested?.value)
* console.log(Array.from(values)) // [10, 20]
*
* // Working with Map.get (returns undefined for missing keys)
* const map = new Map([
* ["a", 1],
* ["b", 2],
* ["c", 3]
* ])
* const keys = ["a", "x", "b", "y", "c"]
* const foundValues = Iterable.flatMapNullishOr(keys, (key) => map.get(key))
* console.log(Array.from(foundValues)) // [1, 2, 3]
* ```
*
* @category sequencing
* @since 4.0.0
*/
(self: Iterable, f: (a: A) => B): Iterable>;
};
/**
* Checks whether a predicate holds true for some `Iterable` element.
*
* **Example** (Checking whether some element matches)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 5, 7, 8]
* const hasEven = Iterable.some(numbers, (x) => x % 2 === 0)
* console.log(hasEven) // true (because of 8)
*
* const allOdd = [1, 3, 5, 7]
* const hasEvenInAllOdd = Iterable.some(allOdd, (x) => x % 2 === 0)
* console.log(hasEvenInAllOdd) // false
*
* // With index
* const letters = ["a", "b", "c"]
* const hasElementAtIndex2 = Iterable.some(letters, (_, i) => i === 2)
* console.log(hasElementAtIndex2) // true
*
* // Early termination - stops at first match
* const infiniteOdds = Iterable.filter(Iterable.range(1), (x) => x % 2 === 1)
* const hasEvenInInfiniteOdds = Iterable.some(
* Iterable.take(infiniteOdds, 1000),
* (x) => x % 2 === 0
* )
* console.log(hasEvenInInfiniteOdds) // false (quickly, doesn't check all 1000)
*
* // Type guard usage
* const mixed: Array = [1, 2, "hello"]
* const hasString = Iterable.some(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(hasString) // true
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const some: {
/**
* Checks whether a predicate holds true for some `Iterable` element.
*
* **Example** (Checking whether some element matches)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 5, 7, 8]
* const hasEven = Iterable.some(numbers, (x) => x % 2 === 0)
* console.log(hasEven) // true (because of 8)
*
* const allOdd = [1, 3, 5, 7]
* const hasEvenInAllOdd = Iterable.some(allOdd, (x) => x % 2 === 0)
* console.log(hasEvenInAllOdd) // false
*
* // With index
* const letters = ["a", "b", "c"]
* const hasElementAtIndex2 = Iterable.some(letters, (_, i) => i === 2)
* console.log(hasElementAtIndex2) // true
*
* // Early termination - stops at first match
* const infiniteOdds = Iterable.filter(Iterable.range(1), (x) => x % 2 === 1)
* const hasEvenInInfiniteOdds = Iterable.some(
* Iterable.take(infiniteOdds, 1000),
* (x) => x % 2 === 0
* )
* console.log(hasEvenInInfiniteOdds) // false (quickly, doesn't check all 1000)
*
* // Type guard usage
* const mixed: Array = [1, 2, "hello"]
* const hasString = Iterable.some(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(hasString) // true
* ```
*
* @category elements
* @since 2.0.0
*/
(predicate: (a: A, i: number) => boolean): (self: Iterable) => boolean;
/**
* Checks whether a predicate holds true for some `Iterable` element.
*
* **Example** (Checking whether some element matches)
*
* ```ts
* import { Iterable } from "effect"
*
* const numbers = [1, 3, 5, 7, 8]
* const hasEven = Iterable.some(numbers, (x) => x % 2 === 0)
* console.log(hasEven) // true (because of 8)
*
* const allOdd = [1, 3, 5, 7]
* const hasEvenInAllOdd = Iterable.some(allOdd, (x) => x % 2 === 0)
* console.log(hasEvenInAllOdd) // false
*
* // With index
* const letters = ["a", "b", "c"]
* const hasElementAtIndex2 = Iterable.some(letters, (_, i) => i === 2)
* console.log(hasElementAtIndex2) // true
*
* // Early termination - stops at first match
* const infiniteOdds = Iterable.filter(Iterable.range(1), (x) => x % 2 === 1)
* const hasEvenInInfiniteOdds = Iterable.some(
* Iterable.take(infiniteOdds, 1000),
* (x) => x % 2 === 0
* )
* console.log(hasEvenInInfiniteOdds) // false (quickly, doesn't check all 1000)
*
* // Type guard usage
* const mixed: Array = [1, 2, "hello"]
* const hasString = Iterable.some(
* mixed,
* (x): x is string => typeof x === "string"
* )
* console.log(hasString) // true
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, predicate: (a: A, i: number) => boolean): boolean;
};
/**
* Generates an iterable by repeatedly applying a function that produces the
* next element and state.
*
* **Details**
*
* This is useful for creating iterables from a generating function that
* maintains state. The function should return `Option.some([value, nextState])`
* to continue or `Option.none()` to stop.
*
* **Example** (Unfolding state into values)
*
* ```ts
* import { Iterable, Option } from "effect"
*
* // Generate Fibonacci sequence
* const fibonacci = Iterable.unfold([0, 1], ([a, b]) => Option.some([a, [b, a + b]]))
* const first10Fib = Iterable.take(fibonacci, 10)
* console.log(Array.from(first10Fib)) // [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
*
* // Generate powers of 2 up to a limit
* const powersOf2 = Iterable.unfold(1, (n) => n <= 1000 ? Option.some([n, n * 2]) : Option.none())
* console.log(Array.from(powersOf2)) // [1, 2, 4, 8, 16, 32, 64, 128, 256, 512]
*
* // Generate countdown
* const countdown = Iterable.unfold(5, (n) => n > 0 ? Option.some([n, n - 1]) : Option.none())
* console.log(Array.from(countdown)) // [5, 4, 3, 2, 1]
*
* // Generate collatz sequence
* const collatz = Iterable.unfold(7, (n) => {
* if (n === 1) return Option.none()
* const next = n % 2 === 0 ? n / 2 : n * 3 + 1
* return Option.some([n, next])
* })
* console.log(Array.from(collatz)) // [7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2]
* ```
*
* @category constructors
* @since 2.0.0
*/
export declare const unfold: (b: B, f: (b: B) => Option) => Iterable;
/**
* Iterates over the `Iterable`, applying `f` to each element.
*
* **Example** (Iterating with side effects)
*
* ```ts
* import { Iterable } from "effect"
*
* // Print each element
* const numbers = [1, 2, 3, 4, 5]
* Iterable.forEach(numbers, (n) => console.log(n))
* // Prints: 1, 2, 3, 4, 5
*
* // Use index in the callback
* const letters = ["a", "b", "c"]
* Iterable.forEach(letters, (letter, i) => {
* console.log(`${i}: ${letter}`)
* })
* // Prints: "0: a", "1: b", "2: c"
*
* // Side effects with any iterable
* const results: Array = []
* Iterable.forEach(Iterable.range(1, 5), (n) => {
* results.push(n * n)
* })
* console.log(results) // [1, 4, 9, 16, 25]
*
* // Process in chunks
* const data = Iterable.chunksOf([1, 2, 3, 4, 5, 6], 2)
* Iterable.forEach(data, (chunk) => {
* console.log(`Processing chunk: ${Array.from(chunk)}`)
* })
* // Prints: "Processing chunk: 1,2", "Processing chunk: 3,4", "Processing chunk: 5,6"
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const forEach: {
/**
* Iterates over the `Iterable`, applying `f` to each element.
*
* **Example** (Iterating with side effects)
*
* ```ts
* import { Iterable } from "effect"
*
* // Print each element
* const numbers = [1, 2, 3, 4, 5]
* Iterable.forEach(numbers, (n) => console.log(n))
* // Prints: 1, 2, 3, 4, 5
*
* // Use index in the callback
* const letters = ["a", "b", "c"]
* Iterable.forEach(letters, (letter, i) => {
* console.log(`${i}: ${letter}`)
* })
* // Prints: "0: a", "1: b", "2: c"
*
* // Side effects with any iterable
* const results: Array = []
* Iterable.forEach(Iterable.range(1, 5), (n) => {
* results.push(n * n)
* })
* console.log(results) // [1, 4, 9, 16, 25]
*
* // Process in chunks
* const data = Iterable.chunksOf([1, 2, 3, 4, 5, 6], 2)
* Iterable.forEach(data, (chunk) => {
* console.log(`Processing chunk: ${Array.from(chunk)}`)
* })
* // Prints: "Processing chunk: 1,2", "Processing chunk: 3,4", "Processing chunk: 5,6"
* ```
*
* @category elements
* @since 2.0.0
*/
(f: (a: A, i: number) => void): (self: Iterable) => void;
/**
* Iterates over the `Iterable`, applying `f` to each element.
*
* **Example** (Iterating with side effects)
*
* ```ts
* import { Iterable } from "effect"
*
* // Print each element
* const numbers = [1, 2, 3, 4, 5]
* Iterable.forEach(numbers, (n) => console.log(n))
* // Prints: 1, 2, 3, 4, 5
*
* // Use index in the callback
* const letters = ["a", "b", "c"]
* Iterable.forEach(letters, (letter, i) => {
* console.log(`${i}: ${letter}`)
* })
* // Prints: "0: a", "1: b", "2: c"
*
* // Side effects with any iterable
* const results: Array = []
* Iterable.forEach(Iterable.range(1, 5), (n) => {
* results.push(n * n)
* })
* console.log(results) // [1, 4, 9, 16, 25]
*
* // Process in chunks
* const data = Iterable.chunksOf([1, 2, 3, 4, 5, 6], 2)
* Iterable.forEach(data, (chunk) => {
* console.log(`Processing chunk: ${Array.from(chunk)}`)
* })
* // Prints: "Processing chunk: 1,2", "Processing chunk: 3,4", "Processing chunk: 5,6"
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, f: (a: A, i: number) => void): void;
};
/**
* Reduces an iterable to a single value by applying a function to each element and accumulating the result.
*
* **Details**
*
* This function applies a reducing function against an accumulator and each element
* of the iterable (from left to right) to reduce it to a single value.
*
* **Example** (Reducing an iterable)
*
* ```ts
* import { Iterable } from "effect"
*
* // Sum all numbers
* const numbers = [1, 2, 3, 4, 5]
* const sum = Iterable.reduce(numbers, 0, (acc, n) => acc + n)
* console.log(sum) // 15
*
* // Find maximum value
* const values = [3, 1, 4, 1, 5, 9, 2]
* const max = Iterable.reduce(values, -Infinity, Math.max)
* console.log(max) // 9
*
* // Build an object from key-value pairs
* const pairs = [["a", 1], ["b", 2], ["c", 3]] as const
* const obj = Iterable.reduce(
* pairs,
* {} as Record,
* (acc, [key, value]) => {
* acc[key] = value
* return acc
* }
* )
* console.log(obj) // { a: 1, b: 2, c: 3 }
*
* // Use index in the reducer
* const letters = ["a", "b", "c"]
* const indexed = Iterable.reduce(
* letters,
* [] as Array,
* (acc, letter, i) => {
* acc.push(`${i}: ${letter}`)
* return acc
* }
* )
* console.log(indexed) // ["0: a", "1: b", "2: c"]
* ```
*
* @category folding
* @since 2.0.0
*/
export declare const reduce: {
/**
* Reduces an iterable to a single value by applying a function to each element and accumulating the result.
*
* **Details**
*
* This function applies a reducing function against an accumulator and each element
* of the iterable (from left to right) to reduce it to a single value.
*
* **Example** (Reducing an iterable)
*
* ```ts
* import { Iterable } from "effect"
*
* // Sum all numbers
* const numbers = [1, 2, 3, 4, 5]
* const sum = Iterable.reduce(numbers, 0, (acc, n) => acc + n)
* console.log(sum) // 15
*
* // Find maximum value
* const values = [3, 1, 4, 1, 5, 9, 2]
* const max = Iterable.reduce(values, -Infinity, Math.max)
* console.log(max) // 9
*
* // Build an object from key-value pairs
* const pairs = [["a", 1], ["b", 2], ["c", 3]] as const
* const obj = Iterable.reduce(
* pairs,
* {} as Record,
* (acc, [key, value]) => {
* acc[key] = value
* return acc
* }
* )
* console.log(obj) // { a: 1, b: 2, c: 3 }
*
* // Use index in the reducer
* const letters = ["a", "b", "c"]
* const indexed = Iterable.reduce(
* letters,
* [] as Array,
* (acc, letter, i) => {
* acc.push(`${i}: ${letter}`)
* return acc
* }
* )
* console.log(indexed) // ["0: a", "1: b", "2: c"]
* ```
*
* @category folding
* @since 2.0.0
*/
(b: B, f: (b: B, a: A, i: number) => B): (self: Iterable) => B;
/**
* Reduces an iterable to a single value by applying a function to each element and accumulating the result.
*
* **Details**
*
* This function applies a reducing function against an accumulator and each element
* of the iterable (from left to right) to reduce it to a single value.
*
* **Example** (Reducing an iterable)
*
* ```ts
* import { Iterable } from "effect"
*
* // Sum all numbers
* const numbers = [1, 2, 3, 4, 5]
* const sum = Iterable.reduce(numbers, 0, (acc, n) => acc + n)
* console.log(sum) // 15
*
* // Find maximum value
* const values = [3, 1, 4, 1, 5, 9, 2]
* const max = Iterable.reduce(values, -Infinity, Math.max)
* console.log(max) // 9
*
* // Build an object from key-value pairs
* const pairs = [["a", 1], ["b", 2], ["c", 3]] as const
* const obj = Iterable.reduce(
* pairs,
* {} as Record,
* (acc, [key, value]) => {
* acc[key] = value
* return acc
* }
* )
* console.log(obj) // { a: 1, b: 2, c: 3 }
*
* // Use index in the reducer
* const letters = ["a", "b", "c"]
* const indexed = Iterable.reduce(
* letters,
* [] as Array,
* (acc, letter, i) => {
* acc.push(`${i}: ${letter}`)
* return acc
* }
* )
* console.log(indexed) // ["0: a", "1: b", "2: c"]
* ```
*
* @category folding
* @since 2.0.0
*/
(self: Iterable, b: B, f: (b: B, a: A, i: number) => B): B;
};
/**
* Deduplicates adjacent elements that are identical using the provided `isEquivalent` function.
*
* **Example** (Deduplicating adjacent elements with custom equivalence)
*
* ```ts
* import { Iterable } from "effect"
*
* // Remove adjacent duplicates with custom equality
* const numbers = [1, 1, 2, 2, 3, 1, 1]
* const dedupedNumbers = Iterable.dedupeAdjacentWith(numbers, (a, b) => a === b)
* console.log(Array.from(dedupedNumbers)) // [1, 2, 3, 1]
*
* // Case-insensitive deduplication
* const words = ["Hello", "HELLO", "world", "World", "test"]
* const caseInsensitive = (a: string, b: string) =>
* a.toLowerCase() === b.toLowerCase()
* const dedupedWords = Iterable.dedupeAdjacentWith(words, caseInsensitive)
* console.log(Array.from(dedupedWords)) // ["Hello", "world", "test"]
*
* // Deduplication by object property
* const users = [
* { id: 1, name: "Alice" },
* { id: 1, name: "Alice Updated" }, // different name, same id
* { id: 2, name: "Bob" },
* { id: 2, name: "Bob" },
* { id: 3, name: "Charlie" }
* ]
* const byId = (a: typeof users[0], b: typeof users[0]) => a.id === b.id
* const dedupedUsers = Iterable.dedupeAdjacentWith(users, byId)
* console.log(Array.from(dedupedUsers).map((u) => u.id)) // [1, 2, 3]
*
* // Approximate numeric equality
* const floats = [1.0, 1.01, 1.02, 2.0, 2.01, 3.0]
* const approxEqual = (a: number, b: number) => Math.abs(a - b) < 0.1
* const dedupedFloats = Iterable.dedupeAdjacentWith(floats, approxEqual)
* console.log(Array.from(dedupedFloats)) // [1.0, 2.0, 3.0]
* ```
*
* @category filtering
* @since 2.0.0
*/
export declare const dedupeAdjacentWith: {
/**
* Deduplicates adjacent elements that are identical using the provided `isEquivalent` function.
*
* **Example** (Deduplicating adjacent elements with custom equivalence)
*
* ```ts
* import { Iterable } from "effect"
*
* // Remove adjacent duplicates with custom equality
* const numbers = [1, 1, 2, 2, 3, 1, 1]
* const dedupedNumbers = Iterable.dedupeAdjacentWith(numbers, (a, b) => a === b)
* console.log(Array.from(dedupedNumbers)) // [1, 2, 3, 1]
*
* // Case-insensitive deduplication
* const words = ["Hello", "HELLO", "world", "World", "test"]
* const caseInsensitive = (a: string, b: string) =>
* a.toLowerCase() === b.toLowerCase()
* const dedupedWords = Iterable.dedupeAdjacentWith(words, caseInsensitive)
* console.log(Array.from(dedupedWords)) // ["Hello", "world", "test"]
*
* // Deduplication by object property
* const users = [
* { id: 1, name: "Alice" },
* { id: 1, name: "Alice Updated" }, // different name, same id
* { id: 2, name: "Bob" },
* { id: 2, name: "Bob" },
* { id: 3, name: "Charlie" }
* ]
* const byId = (a: typeof users[0], b: typeof users[0]) => a.id === b.id
* const dedupedUsers = Iterable.dedupeAdjacentWith(users, byId)
* console.log(Array.from(dedupedUsers).map((u) => u.id)) // [1, 2, 3]
*
* // Approximate numeric equality
* const floats = [1.0, 1.01, 1.02, 2.0, 2.01, 3.0]
* const approxEqual = (a: number, b: number) => Math.abs(a - b) < 0.1
* const dedupedFloats = Iterable.dedupeAdjacentWith(floats, approxEqual)
* console.log(Array.from(dedupedFloats)) // [1.0, 2.0, 3.0]
* ```
*
* @category filtering
* @since 2.0.0
*/
(isEquivalent: (self: A, that: A) => boolean): (self: Iterable) => Iterable;
/**
* Deduplicates adjacent elements that are identical using the provided `isEquivalent` function.
*
* **Example** (Deduplicating adjacent elements with custom equivalence)
*
* ```ts
* import { Iterable } from "effect"
*
* // Remove adjacent duplicates with custom equality
* const numbers = [1, 1, 2, 2, 3, 1, 1]
* const dedupedNumbers = Iterable.dedupeAdjacentWith(numbers, (a, b) => a === b)
* console.log(Array.from(dedupedNumbers)) // [1, 2, 3, 1]
*
* // Case-insensitive deduplication
* const words = ["Hello", "HELLO", "world", "World", "test"]
* const caseInsensitive = (a: string, b: string) =>
* a.toLowerCase() === b.toLowerCase()
* const dedupedWords = Iterable.dedupeAdjacentWith(words, caseInsensitive)
* console.log(Array.from(dedupedWords)) // ["Hello", "world", "test"]
*
* // Deduplication by object property
* const users = [
* { id: 1, name: "Alice" },
* { id: 1, name: "Alice Updated" }, // different name, same id
* { id: 2, name: "Bob" },
* { id: 2, name: "Bob" },
* { id: 3, name: "Charlie" }
* ]
* const byId = (a: typeof users[0], b: typeof users[0]) => a.id === b.id
* const dedupedUsers = Iterable.dedupeAdjacentWith(users, byId)
* console.log(Array.from(dedupedUsers).map((u) => u.id)) // [1, 2, 3]
*
* // Approximate numeric equality
* const floats = [1.0, 1.01, 1.02, 2.0, 2.01, 3.0]
* const approxEqual = (a: number, b: number) => Math.abs(a - b) < 0.1
* const dedupedFloats = Iterable.dedupeAdjacentWith(floats, approxEqual)
* console.log(Array.from(dedupedFloats)) // [1.0, 2.0, 3.0]
* ```
*
* @category filtering
* @since 2.0.0
*/
(self: Iterable, isEquivalent: (self: A, that: A) => boolean): Iterable;
};
/**
* Deduplicates adjacent elements that are identical.
*
* **Example** (Deduplicating adjacent elements)
*
* ```ts
* import { Iterable } from "effect"
*
* // Remove adjacent duplicate numbers
* const numbers = [1, 1, 2, 2, 2, 3, 1, 1]
* const deduped = Iterable.dedupeAdjacent(numbers)
* console.log(Array.from(deduped)) // [1, 2, 3, 1]
*
* // Remove adjacent duplicate characters
* const letters = "aabbccaa"
* const dedupedLetters = Iterable.dedupeAdjacent(letters)
* console.log(Array.from(dedupedLetters)) // ["a", "b", "c", "a"]
*
* // Works with objects using deep equality
* const objects = [
* { type: "A" },
* { type: "A" },
* { type: "B" },
* { type: "B" },
* { type: "A" }
* ]
* const dedupedObjects = Iterable.dedupeAdjacent(objects)
* console.log(Array.from(dedupedObjects).map((o) => o.type)) // ["A", "B", "A"]
*
* // Clean up streaming data
* const sensorData = [100, 100, 100, 101, 101, 102, 102, 102, 100]
* const cleanedData = Iterable.dedupeAdjacent(sensorData)
* console.log(Array.from(cleanedData)) // [100, 101, 102, 100]
* ```
*
* @category filtering
* @since 2.0.0
*/
export declare const dedupeAdjacent: (self: Iterable) => Iterable;
/**
* Zips this Iterable crosswise with the specified Iterable using the specified combiner.
*
* **Example** (Combining cartesian products)
*
* ```ts
* import { Iterable } from "effect"
*
* // Create coordinate pairs
* const xs = [1, 2]
* const ys = ["a", "b", "c"]
* const coordinates = Iterable.cartesianWith(xs, ys, (x, y) => `(${x},${y})`)
* console.log(Array.from(coordinates)) // ["(1,a)", "(1,b)", "(1,c)", "(2,a)", "(2,b)", "(2,c)"]
*
* // Generate all combinations of options
* const sizes = ["S", "M", "L"]
* const colors = ["red", "blue"]
* const products = Iterable.cartesianWith(
* sizes,
* colors,
* (size, color) => ({ size, color })
* )
* console.log(Array.from(products))
* // [
* // { size: "S", color: "red" }, { size: "S", color: "blue" },
* // { size: "M", color: "red" }, { size: "M", color: "blue" },
* // { size: "L", color: "red" }, { size: "L", color: "blue" }
* // ]
*
* // Mathematical operations on all pairs
* const a = [1, 2, 3]
* const b = [10, 20]
* const mathProducts = Iterable.cartesianWith(a, b, (x, y) => x * y)
* console.log(Array.from(mathProducts)) // [10, 20, 20, 40, 30, 60]
*
* // Create test data combinations
* const userTypes = ["admin", "user"]
* const features = ["read", "write", "delete"]
* const testCases = Iterable.cartesianWith(
* userTypes,
* features,
* (user, feature) => `${user}_can_${feature}`
* )
* console.log(Array.from(testCases))
* // ["admin_can_read", "admin_can_write", "admin_can_delete", "user_can_read", "user_can_write", "user_can_delete"]
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const cartesianWith: {
/**
* Zips this Iterable crosswise with the specified Iterable using the specified combiner.
*
* **Example** (Combining cartesian products)
*
* ```ts
* import { Iterable } from "effect"
*
* // Create coordinate pairs
* const xs = [1, 2]
* const ys = ["a", "b", "c"]
* const coordinates = Iterable.cartesianWith(xs, ys, (x, y) => `(${x},${y})`)
* console.log(Array.from(coordinates)) // ["(1,a)", "(1,b)", "(1,c)", "(2,a)", "(2,b)", "(2,c)"]
*
* // Generate all combinations of options
* const sizes = ["S", "M", "L"]
* const colors = ["red", "blue"]
* const products = Iterable.cartesianWith(
* sizes,
* colors,
* (size, color) => ({ size, color })
* )
* console.log(Array.from(products))
* // [
* // { size: "S", color: "red" }, { size: "S", color: "blue" },
* // { size: "M", color: "red" }, { size: "M", color: "blue" },
* // { size: "L", color: "red" }, { size: "L", color: "blue" }
* // ]
*
* // Mathematical operations on all pairs
* const a = [1, 2, 3]
* const b = [10, 20]
* const mathProducts = Iterable.cartesianWith(a, b, (x, y) => x * y)
* console.log(Array.from(mathProducts)) // [10, 20, 20, 40, 30, 60]
*
* // Create test data combinations
* const userTypes = ["admin", "user"]
* const features = ["read", "write", "delete"]
* const testCases = Iterable.cartesianWith(
* userTypes,
* features,
* (user, feature) => `${user}_can_${feature}`
* )
* console.log(Array.from(testCases))
* // ["admin_can_read", "admin_can_write", "admin_can_delete", "user_can_read", "user_can_write", "user_can_delete"]
* ```
*
* @category elements
* @since 2.0.0
*/
(that: Iterable, f: (a: A, b: B) => C): (self: Iterable) => Iterable;
/**
* Zips this Iterable crosswise with the specified Iterable using the specified combiner.
*
* **Example** (Combining cartesian products)
*
* ```ts
* import { Iterable } from "effect"
*
* // Create coordinate pairs
* const xs = [1, 2]
* const ys = ["a", "b", "c"]
* const coordinates = Iterable.cartesianWith(xs, ys, (x, y) => `(${x},${y})`)
* console.log(Array.from(coordinates)) // ["(1,a)", "(1,b)", "(1,c)", "(2,a)", "(2,b)", "(2,c)"]
*
* // Generate all combinations of options
* const sizes = ["S", "M", "L"]
* const colors = ["red", "blue"]
* const products = Iterable.cartesianWith(
* sizes,
* colors,
* (size, color) => ({ size, color })
* )
* console.log(Array.from(products))
* // [
* // { size: "S", color: "red" }, { size: "S", color: "blue" },
* // { size: "M", color: "red" }, { size: "M", color: "blue" },
* // { size: "L", color: "red" }, { size: "L", color: "blue" }
* // ]
*
* // Mathematical operations on all pairs
* const a = [1, 2, 3]
* const b = [10, 20]
* const mathProducts = Iterable.cartesianWith(a, b, (x, y) => x * y)
* console.log(Array.from(mathProducts)) // [10, 20, 20, 40, 30, 60]
*
* // Create test data combinations
* const userTypes = ["admin", "user"]
* const features = ["read", "write", "delete"]
* const testCases = Iterable.cartesianWith(
* userTypes,
* features,
* (user, feature) => `${user}_can_${feature}`
* )
* console.log(Array.from(testCases))
* // ["admin_can_read", "admin_can_write", "admin_can_delete", "user_can_read", "user_can_write", "user_can_delete"]
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, that: Iterable, f: (a: A, b: B) => C): Iterable;
};
/**
* Zips this Iterable crosswise with the specified Iterable.
*
* **Example** (Generating cartesian pairs)
*
* ```ts
* import { Iterable } from "effect"
*
* // All pairs of numbers and letters
* const numbers = [1, 2, 3]
* const letters = ["a", "b"]
* const pairs = Iterable.cartesian(numbers, letters)
* console.log(Array.from(pairs))
* // [[1, "a"], [1, "b"], [2, "a"], [2, "b"], [3, "a"], [3, "b"]]
*
* // Generate coordinate grid
* const x = [0, 1, 2]
* const y = [0, 1]
* const grid = Iterable.cartesian(x, y)
* console.log(Array.from(grid))
* // [[0, 0], [0, 1], [1, 0], [1, 1], [2, 0], [2, 1]]
*
* // All combinations for testing
* const browsers = ["chrome", "firefox"]
* const devices = ["desktop", "mobile", "tablet"]
* const testMatrix = Iterable.cartesian(browsers, devices)
* console.log(Array.from(testMatrix))
* // [
* // ["chrome", "desktop"], ["chrome", "mobile"], ["chrome", "tablet"],
* // ["firefox", "desktop"], ["firefox", "mobile"], ["firefox", "tablet"]
* // ]
*
* // Empty iterable results in empty cartesian product
* const empty = Iterable.empty()
* const withEmpty = Iterable.cartesian([1, 2], empty)
* console.log(Array.from(withEmpty)) // []
* ```
*
* @category elements
* @since 2.0.0
*/
export declare const cartesian: {
/**
* Zips this Iterable crosswise with the specified Iterable.
*
* **Example** (Generating cartesian pairs)
*
* ```ts
* import { Iterable } from "effect"
*
* // All pairs of numbers and letters
* const numbers = [1, 2, 3]
* const letters = ["a", "b"]
* const pairs = Iterable.cartesian(numbers, letters)
* console.log(Array.from(pairs))
* // [[1, "a"], [1, "b"], [2, "a"], [2, "b"], [3, "a"], [3, "b"]]
*
* // Generate coordinate grid
* const x = [0, 1, 2]
* const y = [0, 1]
* const grid = Iterable.cartesian(x, y)
* console.log(Array.from(grid))
* // [[0, 0], [0, 1], [1, 0], [1, 1], [2, 0], [2, 1]]
*
* // All combinations for testing
* const browsers = ["chrome", "firefox"]
* const devices = ["desktop", "mobile", "tablet"]
* const testMatrix = Iterable.cartesian(browsers, devices)
* console.log(Array.from(testMatrix))
* // [
* // ["chrome", "desktop"], ["chrome", "mobile"], ["chrome", "tablet"],
* // ["firefox", "desktop"], ["firefox", "mobile"], ["firefox", "tablet"]
* // ]
*
* // Empty iterable results in empty cartesian product
* const empty = Iterable.empty()
* const withEmpty = Iterable.cartesian([1, 2], empty)
* console.log(Array.from(withEmpty)) // []
* ```
*
* @category elements
* @since 2.0.0
*/
(that: Iterable): (self: Iterable) => Iterable<[A, B]>;
/**
* Zips this Iterable crosswise with the specified Iterable.
*
* **Example** (Generating cartesian pairs)
*
* ```ts
* import { Iterable } from "effect"
*
* // All pairs of numbers and letters
* const numbers = [1, 2, 3]
* const letters = ["a", "b"]
* const pairs = Iterable.cartesian(numbers, letters)
* console.log(Array.from(pairs))
* // [[1, "a"], [1, "b"], [2, "a"], [2, "b"], [3, "a"], [3, "b"]]
*
* // Generate coordinate grid
* const x = [0, 1, 2]
* const y = [0, 1]
* const grid = Iterable.cartesian(x, y)
* console.log(Array.from(grid))
* // [[0, 0], [0, 1], [1, 0], [1, 1], [2, 0], [2, 1]]
*
* // All combinations for testing
* const browsers = ["chrome", "firefox"]
* const devices = ["desktop", "mobile", "tablet"]
* const testMatrix = Iterable.cartesian(browsers, devices)
* console.log(Array.from(testMatrix))
* // [
* // ["chrome", "desktop"], ["chrome", "mobile"], ["chrome", "tablet"],
* // ["firefox", "desktop"], ["firefox", "mobile"], ["firefox", "tablet"]
* // ]
*
* // Empty iterable results in empty cartesian product
* const empty = Iterable.empty()
* const withEmpty = Iterable.cartesian([1, 2], empty)
* console.log(Array.from(withEmpty)) // []
* ```
*
* @category elements
* @since 2.0.0
*/
(self: Iterable, that: Iterable): Iterable<[A, B]>;
};
/**
* Computes how many elements of the iterable pass the given predicate.
*
* **Example** (Counting matching elements)
*
* ```ts
* import { Iterable } from "effect"
*
* const result = Iterable.countBy([1, 2, 3, 4, 5], (n) => n % 2 === 0)
* console.log(result) // 2
* ```
*
* @category folding
* @since 3.16.0
*/
export declare const countBy: {
/**
* Computes how many elements of the iterable pass the given predicate.
*
* **Example** (Counting matching elements)
*
* ```ts
* import { Iterable } from "effect"
*
* const result = Iterable.countBy([1, 2, 3, 4, 5], (n) => n % 2 === 0)
* console.log(result) // 2
* ```
*
* @category folding
* @since 3.16.0
*/
(predicate: (a: NoInfer, i: number) => boolean): (self: Iterable) => number;
/**
* Computes how many elements of the iterable pass the given predicate.
*
* **Example** (Counting matching elements)
*
* ```ts
* import { Iterable } from "effect"
*
* const result = Iterable.countBy([1, 2, 3, 4, 5], (n) => n % 2 === 0)
* console.log(result) // 2
* ```
*
* @category folding
* @since 3.16.0
*/
(self: Iterable, predicate: (a: A, i: number) => boolean): number;
};
//# sourceMappingURL=Iterable.d.ts.map