@extra-iterable/flatten v1.1.1

Flatten values in iterable, like _.flatten().

const flatten = require('@extra-iterable/flatten');
// flatten(<iterable>, [level=-1], [begin=0], [end], [target=[]], [at])

flatten([0, [1, [2, new Set([3])]]]);
// [0, 1, 2, 3]
flatten([0, [1, [2, new Set([3])]]], 1);
// [0, 1, [2, Set {3}]]
flatten([0, [1], [[2]], [[new Set([3])]]], -1, 1);
// [1, 2, 3]
flatten([0, [1], [[2]], [[new Set([3])]]], -1, 1, 3);
// [1, 2]
flatten([0, [1], [[2]], [[new Set([3])]]], -1, 1, 3, [10, 11]);
// [10, 11, 1, 2]
flatten([0, [1], [[2]], [[new Set([3])]]], -1, 1, 3, [10, 11], 1);
// [10, 1, 2]