40 lines
1.6 KiB
Markdown
40 lines
1.6 KiB
Markdown
|
# Hints
|
||
|
|
|
||
|
|
## General
|
||
|
|
|
||
|
|
- Read about processes in the official [Getting Started guide][getting-started-processes].
|
||
|
|
- Read [this blog post][mullen-processes] about Elixir processes.
|
||
|
|
|
||
|
|
## 1. Start the machine
|
||
|
|
|
||
|
|
- The machine should run in a new process. There is [a built-in function that starts a new process][kernel-spawn-1].
|
||
|
|
- You will need another function that the new process will execute.
|
||
|
|
|
||
|
|
## 2. Report the machine state
|
||
|
|
|
||
|
|
- The machine's process needs to respond to messages.
|
||
|
|
- There is [a built-in function that waits for a message to arrive in the process's mailbox][kernel-receive].
|
||
|
|
- There is [a built-in function that sends a message to another process][kernel-send].
|
||
|
|
- Use recursion to wait for more than one message.
|
||
|
|
- Pass the machine's state as an argument to the recursive function.
|
||
|
|
|
||
|
|
## 3. Give out numbers
|
||
|
|
|
||
|
|
- This step is conceptually the same as the previous step. The only difference is the need to update the machine's state.
|
||
|
|
|
||
|
|
## 4. Stop the machine
|
||
|
|
|
||
|
|
- This step doesn't require sending any messages as a response.
|
||
|
|
- A process will exit if it has no more code to execute.
|
||
|
|
- This is a base case of the recursive function.
|
||
|
|
|
||
|
|
## 5. Ignore unexpected messages
|
||
|
|
|
||
|
|
- This step doesn't require sending any messages as a response.
|
||
|
|
- You can use `_` to match all messages that didn't match previous patterns.
|
||
|
|
|
||
|
|
[getting-started-processes]: https://elixir-lang.org/getting-started/processes.html
|
||
|
|
[mullen-processes]: https://samuelmullen.com/articles/elixir-processes-send-and-receive
|
||
|
|
[kernel-spawn-1]: https://hexdocs.pm/elixir/Kernel.html#spawn/1
|
||
|
|
[kernel-receive]: https://hexdocs.pm/elixir/Kernel.SpecialForms.html#receive/1
|
||
|
|
[kernel-send]: https://hexdocs.pm/elixir/Kernel.html#send/2
|