Modules in Elixir
Modules in Elixir
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.