Bang

Bang simply adds dynamic bang(!) functions to your existing module functions with after-callback.

Installation

If available in Hex, the package can be installed as:

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

def deps do
  [{:bang, "~> 0.1.0"}]
end

2. Ensure bang is started before your application:

def application do
  [applications: [:bang]]
end

Usage

Bang uses accumulated approach by definition. So, you can define several bangs inside your module and can use different callback for each @bang function.

defmodule SampleModule do
  use Bang

  # @bang {[list_of_func_name_arg_count_tuples], {CallbackModule, :callback_fn}}

  @bang {[welcome: 1, welcome: 2], {SampleModule, :titleize}}
  def welcome(name), do: "Welcome #{name}!"
  def welcome(prefix, name), do: "Welcome #{prefix}. #{name}!"

  @bang {[good_bye: 1, good_bye: 2], {SampleModule, :titleize}}
  def good_bye(name), do: "Good bye #{name}!"
  def good_bye(prefix, name), do: "Good bye #{prefix}. #{name}!"

  def titleize(str) do
    str
    |> String.split(" ")
    |> Enum.map(fn(word) -> String.capitalize(word) end)
    |> Enum.join(" ")
  end
end

SampleModule.welcome("john doe") |> SampleModule.titleize == SampleModule.welcome!("john doe")

The code above will add welcome!: 1, welcome!:2, good_bye!: 1, good_bye!: 2 functions to the SampleModule

How to add bang function to existing public functions list of the module?

Open your iex console with iex -S mix command and run for

iex> SomeModule.__info__(:functions)
# will result with list of tuples

And then add bang function as usual using the output list.

defmodule SomeModule
  use Bang

  ...
  @bang {[list_of_tuples], {SomeOtherModule, :func_name}}
  ...
end

Contributing

Issues, Bugs, Documentation, Enhancements

1. Fork the project

2. Make your improvements and write your tests.

3. Make a pull request.