mirror of
https://github.com/bevyengine/bevy
synced 2024-11-25 22:20:20 +00:00
26 lines
860 B
Rust
26 lines
860 B
Rust
use anyhow::Result;
|
|
use bevy::prelude::*;
|
|
|
|
fn main() {
|
|
App::new()
|
|
.insert_resource(Message("42".to_string()))
|
|
.add_system(parse_message_system.system().chain(handler_system.system()))
|
|
.run();
|
|
}
|
|
|
|
struct Message(String);
|
|
|
|
// this system produces a Result<usize> output by trying to parse the Message resource
|
|
fn parse_message_system(message: Res<Message>) -> Result<usize> {
|
|
Ok(message.0.parse::<usize>()?)
|
|
}
|
|
|
|
// This system takes a Result<usize> input and either prints the parsed value or the error message
|
|
// Try changing the Message resource to something that isn't an integer. You should see the error
|
|
// message printed.
|
|
fn handler_system(In(result): In<Result<usize>>) {
|
|
match result {
|
|
Ok(value) => println!("parsed message: {}", value),
|
|
Err(err) => println!("encountered an error: {:?}", err),
|
|
}
|
|
}
|