OK Elixir

Effecient error handling in elixir pipelines. See Handling Errors in Elixir for a more detailed explination

Documentation for OK is available on hexdoc

Installation

Available in Hex, the package can be installed as:

1. Add ok to your list of dependencies in mix.exs:

   def deps do [{:ok, "~> 0.0.1"}] end

Usage

The OK module works with the native error handling in Erlang/Elixir, that is a result tuple. A result tuple is a two-tuple tagged either as a success(:ok) or a failure(:error).

{:ok, value} | {:error, reason}

'~>>' Macro

This macro allows pipelining result tuples through a pipeline of functions.

import OK, only: :macros

def get_employee_data(file, name) do
  {:ok, file}
  ~>> File.read
  ~>> Poison.decode
  ~>> Dict.fetch(name)
end

def handle_user_data({:ok, data}), do: IO.puts("Contact at #{data["email"]}")
def handle_user_data({:error, :enoent}), do: IO.puts("File not found")
def handle_user_data({:error, {:invalid, _}}), do: IO.puts("Invalid JSON")
def handle_user_data({:error, :key_not_found}), do: IO.puts("Could not find employee")

get_employee_data("my_company/employees.json")
|> handle_user_data