Elixir

Phoenix Webframework is the Rails like framework in the Elixir ecosystem.

Publishing a package to elixir

mix hex.publish

Ternary Operator

While elixir does not have a ternary operator, one can be achieved with:

if (expression), do: true_value, else: false_value

Behaviours

Behaviours are similar to interface in Object Oriented Programming. The behaviour module defines the generic interface, and the callback module implements that interface.

defmodule MyBehaviour do
  @callback vital_fun() :: any
  @callback non_vital_fun() :: any
  @macrocallback non_vital_macro(arg :: any) :: Macro.t
  @optional_callbacks non_vital_fun: 0, non_vital_macro: 1
end

And then an implementation would look like:

defmodule MyBehaviour do
  def vital_fun() do
    :hello
  end
 
  @macrocallback non_vital_macro(arg :: any) :: Macro.t
  @optional_callbacks non_vital_fun: 0, non_vital_macro: 1
end

Re-arranging Parameters in a call then

When dealing with a chain, and the result of the previous call needs to be pass into a position other than the first spot, use then

|> get_value()
|> then(fn value -> Map.put(some_map, "key", value) end)

or more succinctly using short hand:

|> get_value()
|> then(&(Map.put(some_map, "key", &1)))

Regex

Elixir Regex Tester

Debugging elixir hacks

dbg is incredibly helpful for debugging a chain of method calls:

%{abc: 1, def: 2}
|> change_1()
|> change_2()
|> dbg()

This is the equivalent of

%{abc: 1, def: 2}
|> IO.inspect()
|> change_1()
|> IO.inspect()
|> change_2()
|> IO.inspect()