Stream.map_every

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Link to this function

map_every(enum, nth, fun)

View Source (since 1.4.0)

Specs

map_every(Enumerable.t(), non_neg_integer(), (element() -> any())) ::
  Enumerable.t()

Creates a stream that will apply the given function on every nth element from the enumerable.

The first element is always passed to the given function.

nth must be a non-negative integer.

Examples

iex> stream = Stream.map_every(1..10, 2, fn x -> x * 2 end)
iex> Enum.to_list(stream)
[2, 2, 6, 4, 10, 6, 14, 8, 18, 10]

iex> stream = Stream.map_every([1, 2, 3, 4, 5], 1, fn x -> x * 2 end)
iex> Enum.to_list(stream)
[2, 4, 6, 8, 10]

iex> stream = Stream.map_every(1..5, 0, fn x -> x * 2 end)
iex> Enum.to_list(stream)
[1, 2, 3, 4, 5]