Agent in Elixir
Agent in Elixir[edit]
The `Agent` module in Elixir is a part of the `Concurrent` module that allows the creation and management of concurrent state. It provides a simple and efficient way to manage state within a single process or across multiple processes.
Creating an Agent[edit]
To create an agent, the `Agent.start_link/2` function is used. This function takes two arguments: the agent's initial state and an optional keyword list of options.
```elixir {:ok, agent} = Agent.start_link(fn -> initial_state end, name: :my_agent) ```
Accessing Agent State[edit]
The state of an agent can be accessed using the `Agent.get/2` function. It takes two arguments: the agent and a function that receives the current state and returns a new state.
```elixir {:ok, state} = Agent.get(agent, fn current_state -> current_state end) ```
Updating Agent State[edit]
The state of an agent can be updated using the `Agent.update/3` function. It takes three arguments: the agent, a function that receives the current state and returns a new state, and an optional timeout.
```elixir {:ok, new_state} = Agent.update(agent, fn current_state -> new_state end) ```
Sending Messages to Agents[edit]
Agents can also receive messages using the `Agent.send/3` function. The function takes three arguments: the agent, a message, and an optional timeout.
```elixir {:ok, _} = Agent.send(agent, message) ```
Error Handling[edit]
If an error occurs while executing a function within an agent, the error can be handled using the `Agent.get_and_update/3` function. This function takes three arguments: the agent, a function that receives the current state and returns a new state, and an optional timeout.
```elixir {:ok, new_state} = Agent.get_and_update(agent, fn current_state -> new_state end) ```
Conclusion[edit]
Agents in Elixir provide a simple yet efficient way to manage state in concurrent programming. With their easy-to-use API, agents are a powerful tool for handling mutable state in functional programs.