CODEWITHSUNDEEP
elixirreduce
Augustin Riedinger
Augustin Riedinger

Reputation: 22170

Elixir : reduce enum over list of functions

I just wrote:

def transform(list_of_functions, elem) do
  Enum.reduce(list_of_functions, elem, fn func, res when is_function(func) -> func.(res) end)
end

To be called like:

transform([
  &(2*&1),
  fn x -> x % 3 end,
  &Integer.to_string/1
], 5) # "1"

But it feels so elementary that I'm wondering if such function exists in Elixir itself. I would have expected Enum.transform/2 but it doesn't exist. :( Does it with another name?

Upvotes: 0

Views: 410

Answers (1)

Aleksei Matiushkin
Aleksei Matiushkin

Reputation: 121000

This is counter-idiomatic in . We usually use pipe operator |> for that.

Sidenote: % is not an operator to perform modulo division, btw, rem/2 is.

5
|> Kernel.*(2)
|> rem(3)
|> Integer.to_string()
#⇒ "1"

Of course, if needed, that might be written in foldl notation.

Enum.reduce([
  &(2*&1),
  &rem(&1, 3),
  &Integer.to_string/1
], 5, & &2 |> &1.()) 
#⇒ "1"

But still, elixir is not haskell, carrying functions is not how idiomatic code is being written.

Upvotes: 4

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