CODEWITHSUNDEEP
importelixir
Rohan Pujari
Rohan Pujari

Reputation: 838

Calling imported module functions directly in elixir

I have just started learning Elixir and I am unable to figure out how import works in Elixir. When I import a module into another module using import I am unable to call the imported function by using the module in which it is imported.

But I am able to call function of imported module inside function in the module which it was imported.

defmodule A do
  def func do
   IO.puts("func called")
  end
end

defmodule B do
  import A
end

A.func # o/p: "func called"
B.func # (UndefinedFunctionError) undefined function: B.func/0

defmodule B do
  import A

  def func2 do
    func
  end
end

B.func2 # o/p "func called"

I am unable to figure out why B.func not works while I was able to call func from func2. Is there some kind of theory that I am missing. Coming from the Ruby background this behaviour looks odd to me. Please can anybody help me out or point me to some good resource to read.

Upvotes: 1

Views: 1956

Answers (1)

jisaacstone
jisaacstone

Reputation: 4284

import does not really import anything in the way many other languages do. All it does is makes the imported module's exported functions accessible from the current namespace. To quote the docs

We use import whenever we want to easily access functions or macros from other modules without using the fully-qualified name.

If you want A.func and B.func to point to the same function you have a couple options. The first is simple - make a wrapper function:

defmodule B do
  def func do
     A.func
  end
end

If you want some more complex inheritance type stuff you can look into creating a __using__ macro with defoverridable and super

Upvotes: 5

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