Inherit

Inherit provides a way to create pseudo-inheritance in Elixir by allowing modules to inherit struct fields and delegate function calls from other modules.

Features

• Struct inheritance: Child modules inherit all fields from parent modules
• Function delegation: Public functions from parent modules are automatically delegated
• Field merging: Child modules can add additional fields to inherited structs
• Overridable functions: Inherited functions can be overridden in child modules

Usage

Making a module inheritable

Use Inherit in your module and define struct fields:

defmodule Person do
  use Inherit, [
    name: "",
    age: 0
  ]

  def greet(person) do
    "Hello, I'm #{person.name} and I'm #{person.age} years old"
  end

  def adult?(person) do
    person.age >= 18
  end
end

Inheriting from a module

Use the parent module in your child module and specify additional fields:

defmodule Employee do
  use Person, [
    salary: 0,
    department: ""
  ]

  # Override parent function
  def greet(employee) do
    "Hi, I'm #{employee.name}, I work in #{employee.department}"
  end
end

Using the inherited module

# Create an Employee struct with inherited fields
employee = %Employee{
  name: "John",
  age: 30,
  salary: 50000,
  department: "Engineering"
}

# Call overridden function
Employee.greet(employee)
# => "Hi, I'm John, I work in Engineering"

# Call inherited function
Employee.adult?(employee)
# => true

How it works

1. Parent module setup: When you use Inherit, the module becomes inheritable and defines its own struct
2. Inheritance: When you use ParentModule, the child module:
   • Inherits all struct fields from the parent
   • Adds any additional fields specified
   • Delegates all public functions from the parent module
   • Makes inherited functions overridable

Installation

If available in Hex, the package can be installed by adding inherit to your list of dependencies in mix.exs:

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

Documentation

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/inherit.