Bottle

Bottle provides a set of custom guards which help reduce a lot of boilerplate coode.

You can find the package in hex.pm and the documentation in hexdocs.pm.

Installation

The the package can be installed from Hex, by adding bottle to your list of dependencies in mix.exs:

def deps do
  [
    {:bottle, "~> 1.0"}
  ]
end

Usage

Just put use Bottle on top of your module and get all the guards available in your scope:

defmodule MyModule do
  use Bottle

  def what_is(sub) when is_empty_binary(sub) do
    :empty_binary
  end

  def what_is(sub) when is_non_empty_binary_shorter_than(sub, 10) do
    :non_empty_binary_shorter_than_10_bytes
  end

  def what_is(sub) when is_non_empty_map(sub) do
    :non_empty_map
  end

  def what_is(sub) when is_empty_map(sub) do
    :empty_map
  end

  def what_is(sub) when is_zero(sub) do
    :zero_integer_or_float
  end

  def what_is(sub) when is_pos_number(sub) do
    :number_greater_than_0
  end

  def what_is(sub) when is_non_neg_integer(sub) do
    :integer_equal_or_greater_than_0
  end

  def what_is(sub) when is_non_zero_float(sub) do
    :non_zero_float
  end
end

You can also import the guards selectively using import, ie:

import Bottle.Binary, only: [is_empty_binary: 1]

Documentation

You can find the complete list of guards in the documentation: https://hexdocs.pm/bottle.

License

Bottle is available under the BSD 3-Clause aka "BSD New" license