filter
filter() function
Return Iterable/AsyncIterable of all elements f returns truthy for
Signature:
declare function filter<A>(f: BooleanConstructor, iterable: Iterable<A>): IterableIterator<TruthyTypesOf<A>>;
Returns:
IterableIterator<TruthyTypesOf<A>>
Example
const iter = filter((a)=> a % 2 === 0, [0, 1, 2, 3, 4, 5, 6]);
iter.next() // {done:false, value: 0}
iter.next() // {done:false, value: 2}
iter.next() // {done:false, value: 4}
iter.next() // {done:false, value: 6}
iter.next() // {done:true, value: undefined}
// with pipe
pipe(
[0, 1, 2, 3, 4, 5, 6],
filter(a => a % 2 === 0),
toArray,
); // [0, 2, 4, 6]
await pipe(
Promise.resolve([0, 1, 2, 3, 4, 5, 6]),
filter(a => a % 2 === 0),
toArray,
); // [0, 2, 4, 6]
// if you want to use asynchronous callback
await pipe(
Promise.resolve([0, 1, 2, 3, 4, 5, 6]),
toAsync,
filter(async a => a % 2 === 0),
toArray,
); // [0, 2, 4, 6]
// toAsync
await pipe(
[Promise.resolve(0), Promise.resolve(1), Promise.resolve(2), Promise.resolve(3),
Promise.resolve(4), Promise.resolve(5), Promise.resolve(6)],
toAsync,
filter(a => a % 2 === 0),
toArray,
); // [0, 2, 4, 6]