View Source Getting Started

This guide provides installation and basic usage information for getting started quickly with Bond.

Refer to the Bond module docs for detailed usage instructions and examples.

Installation

bond can be installed by adding it to your list of dependencies in mix.exs:

def deps do
  [
    {:bond, "~> 0.8.3"}
  ]
endcopy

Quick start

Use Bond to define preconditions and postconditions (collectively referred to as "contracts") to functions.

defmodule Math do
  use Bond

  @pre numeric_x: is_number(x), non_negative_x: x >= 0
  @post float_result: is_float(result),
        non_negative_result: result >= 0.0,
        "sqrt of 0 is 0": (x == 0) ~> (result === 0.0),
        "sqrt of 1 is 1": (x == 1) ~> (result === 1.0),
        "x > 1 implies result smaller than x": (x > 1) ~> (result < x)
  def sqrt(x), do: :math.sqrt(x)
endcopy