exercism/elixir/strain/strain.exs

28 lines
662 B
Elixir

defmodule Strain do
@doc """
Given a `list` of items and a function `fun`, return the list of items where
`fun` returns true.
Do not use `Enum.filter`.
"""
@spec keep(list :: list(any), fun :: (any -> boolean)) :: list(any)
def keep(list, fun) do
for item <- list, fun.(item), into: [] do
item
end
end
@doc """
Given a `list` of items and a function `fun`, return the list of items where
`fun` returns false.
Do not use `Enum.reject`.
"""
@spec discard(list :: list(any), fun :: (any -> boolean)) :: list(any)
def discard(list, fun) do
for item <- list, not fun.(item), into: [] do
item
end
end
end