mirror of
https://github.com/bevyengine/bevy
synced 2024-11-22 20:53:53 +00:00
26 lines
862 B
Rust
26 lines
862 B
Rust
use anyhow::Result;
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use bevy::prelude::*;
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fn main() {
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App::build()
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.insert_resource(Message("42".to_string()))
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.add_system(parse_message_system.system().chain(handler_system.system()))
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.run();
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}
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struct Message(String);
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// this system produces a Result<usize> output by trying to parse the Message resource
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fn parse_message_system(message: Res<Message>) -> Result<usize> {
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Ok(message.0.parse::<usize>()?)
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}
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// This system takes a Result<usize> input and either prints the parsed value or the error message
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// Try changing the Message resource to something that isn't an integer. You should see the error
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// message printed.
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fn handler_system(In(result): In<Result<usize>>) {
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match result {
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Ok(value) => println!("parsed message: {}", value),
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Err(err) => println!("encountered an error: {:?}", err),
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}
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}
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