Editing
GenStatem (Elixir)
(section)
Jump to navigation
Jump to search
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
== GenStatem (Elixir) == [[File:elixir-logo.png|thumb|right|200px|Elixir Programming Language Logo]] GenStatem is a behavior module in Elixir's standard library that provides a way to define and implement state machines. State machines are a powerful tool for managing complex stateful systems, and GenStatem makes it easy to create and manage them in Elixir. === Overview === GenStatem allows developers to define states and define how state transitions occur based on events. It follows the "actor" model, where each state is modeled as a separate actor, allowing for concurrent execution and efficient use of resources. === Usage === To use GenStatem, developers need to define a module that implements the behavior defined by GenStatem. This module must define a set of callbacks that handle state transitions, events, and other behavior specific to the state machine. An example of a module implementing the GenStatem behavior: ```elixir defmodule MyStateMachine do use GenStatem def init(:my_init_state, _args) do {:ok, :my_init_state} end def state_handle_event(:my_init_state, :my_event, data) do # Handle the event in the 'my_init_state' state {:next_state, :my_next_state, data} end def state_handle_event(:my_next_state, :my_event, data) do # Handle the event in the 'my_next_state' state {:next_state, :my_next_state, data} end end ``` This example defines a simple state machine with two states: `:my_init_state` and `:my_next_state`. The `init/2` callback initializes the state machine by returning the initial state. The `state_handle_event/3` callbacks define how events are handled in each state. To start the state machine, the `GenStatem.start_link/3` function is used: ```elixir GenStatem.start_link(__MODULE__, :my_init_state, []) ``` === Features === GenStatem provides several features to simplify state machine implementation: ==== Hierarchical States ==== GenStatem supports hierarchical states, allowing for more complex state machines to be modeled. States can be nested within each other, forming a hierarchy that represents the different levels of behavior in the system. ==== State Entry and Exit Actions ==== Each state can define entry and exit actions, which are executed when entering or leaving the state, respectively. This allows for fine-grained control over the behavior of the state machine at different points in its execution. ==== Timeouts ==== GenStatem supports timeouts, allowing events to be triggered automatically if a certain amount of time passes without any relevant events occurring. This is useful for implementing time-based behavior in state machines. === Conclusion === GenStatem is a powerful tool for managing stateful systems in Elixir. With its support for hierarchical states, entry and exit actions, and timeouts, it provides a flexible and expressive way to model complex behaviors. By leveraging GenStatem, developers can build robust and scalable systems in Elixir. [[Category:Programming Languages]] [[Category:Elixir (programming language)]] [[Category:Software Development]]
Summary:
Please note that all contributions to Elixir Wiki may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see
Elixir Wiki:Copyrights
for details).
Do not submit copyrighted work without permission!
Cancel
Editing help
(opens in new window)
Navigation menu
Personal tools
Not logged in
Talk
Contributions
Create account
Log in
Namespaces
Page
Discussion
English
Views
Read
Edit
View history
More
Navigation
Main page
Recent changes
Random page
Help about MediaWiki
Tools
What links here
Related changes
Special pages
Page information