Editing Modules in Elixir

== Modules in Elixir ==
[[File:Elixir_logo.png|thumb|right|150px|Elixir logo]]

In Elixir programming language, a module is a container for functions, data structures, and other definitions. Modules provide a way to organize code and create reusable components. They are fundamental building blocks for creating powerful and maintainable applications in Elixir.

=== Defining Modules ===
A module can be defined using the `defmodule` keyword followed by the module name. It is convention to use PascalCase for module names.

```elixir
defmodule MyModule do
  # module definitions
end
```

=== Functions in Modules ===
Modules can contain function definitions. Functions defined within a module are usually invoked using the dot notation (e.g., `Module.function(args)`).

```elixir
defmodule MyModule do
  def my_function(arg1, arg2) do
    # function body
  end
end
```

=== Module Attributes ===
Attributes can be attached to modules using the `@` syntax. They are used to store metadata or configuration values associated with the module.

```elixir
defmodule MyModule do
  @attribute "value"

  # access the attribute with @attribute
end
```

=== Importing Modules ===
Other modules can be imported using the `import` statement. This allows easy access to imported module functions without requiring the module name prefix.

```elixir
defmodule MyModule do
  import OtherModule

  # Imported module functions can be used directly
  def my_function() do
    imported_function()
  end
end
```

=== Access Modifiers ===
Modules in Elixir provide a way to control the visibility and accessibility of functions and variables using access modifiers such as `private` and `def`.

```elixir
defmodule MyModule do
  def public_function() do
    # can be called from other modules
  end

  defp private_function() do
    # can only be called from within the module
  end
end
```

=== Documentation ===
Modules can include documentation to describe the purpose, usage, and API of the module. This documentation can be accessed using the `h` helper or the `@doc` attribute.

```elixir
defmodule MyModule do
  @doc """
  This module provides utility functions for handling strings.
  """

  # Function definitions with documentation
  @doc """
  Returns the length of the given string.
  """
  def string_length(str) do
    # implementation
  end
end
```

=== Module Attributes ===
Module attributes can be used for various purposes including configuration, metadata, or storing constants. They are defined using the `@` symbol and are accessible throughout the module.

```elixir
defmodule MyModule do
  @api_key "xyz"
  
  # Access the module attribute using @api_key
end
```

=== Conclusion ===
Modules in Elixir are essential for organizing code and creating reusable components. They provide a structured and maintainable way to define functions, store data, and control visibility. Understanding the concept and usage of modules is crucial for building robust and scalable applications in Elixir.

== See Also ==
* [[Functions in Elixir]]
* [[Pattern Matching in Elixir]]
* [[Processes in Elixir]]

[[Category:Elixir]]
[[Category:Programming Languages]]