@lou.codes/iterables
Version:
🔁 Iterable and AsyncIterable utils
26 lines (25 loc) • 815 B
TypeScript
import type {
Predicate,
ReadOnlyIterable,
Single,
Unary,
} from "@lou.codes/types";
/**
* Filters items in an iterable against a predicate and returns items that
* evaluated to `true`.
*
* @category Generators
* @example
* ```typescript
* const filterEven = filter((number: number) => number % 2 === 0);
*
* iterableToArray(filterEven([1, 2, 3, 4])); // [2, 4]
* iterableToArray(filterEven([1, 3, 5, 7])); // []
* ```
* @param predicate Predicate function to evaluate each item.
* @returns Curried function with `predicate` set in context.
*/
export declare const filter: <Item, Filtered extends Item = never>(
predicate: Single<Filtered> extends Single<never> ? Unary<Item, boolean>
: Predicate<Item, Filtered>,
) => (iterable: ReadOnlyIterable<Item>) => Readonly<IterableIterator<Filtered>>;