pub fn all(it: Iterator(a), f: fn(a) -> Bool) -> Bool

pub fn any(it: Iterator(a), f: fn(a) -> Bool) -> Bool

pub fn chain(
  left: Iterator(a),
  right: Iterator(a),
) -> Iterator(a)

pub fn count(it: Iterator(a)) -> Int

pub fn cycle(list: List(a)) -> Iterator(a)

pub fn done(it: Iterator(a)) -> Bool

pub fn enumerate(
  it: Iterator(a),
  start: Int,
) -> Iterator(#(Int, a))

pub fn filter(it: Iterator(a), f: fn(a) -> Bool) -> Iterator(a)

pub fn filter_values(
  it: Iterator(#(k, v)),
  f: fn(v) -> Bool,
) -> Iterator(#(k, v))

pub fn find(
  it: Iterator(a),
  f: fn(a) -> Bool,
) -> option.Option(a)

pub fn fold(it: Iterator(a), acc: b, f: fn(b, a) -> b) -> b

pub fn for_each(it: Iterator(a), f: fn(a) -> Nil) -> Nil

pub fn from_dict(dict: dict.Dict(a, b)) -> Iterator(#(a, b))

pub fn from_list(list: List(a)) -> Iterator(a)

pub fn map(it: Iterator(a), f: fn(a) -> b) -> Iterator(b)

pub fn map_values(
  it: Iterator(#(k, v)),
  f: fn(v) -> w,
) -> Iterator(#(k, w))

pub fn naturals(start: Int) -> Iterator(Int)

pub fn next(it: Iterator(a)) -> option.Option(#(a, Iterator(a)))

pub fn nth(it: Iterator(a), n: Int) -> option.Option(a)

pub fn partition(
  it: Iterator(a),
  f: fn(a) -> Bool,
) -> #(List(a), List(a))

pub fn partition_result(
  it: Iterator(Result(a, b)),
) -> #(List(a), List(b))

pub fn skip(it: Iterator(a), count: Int) -> Iterator(a)

pub fn take(it: Iterator(a), count: Int) -> Iterator(a)

pub fn take_while(
  it: Iterator(a),
  f: fn(a) -> Bool,
) -> Iterator(a)

pub fn to_dict(it: Iterator(#(a, b))) -> dict.Dict(a, b)

pub fn to_list(it: Iterator(a)) -> List(a)

pub fn zip(
  it1: Iterator(a),
  it2: Iterator(b),
) -> Iterator(#(a, b))