ev3dev_lang_rust/
findable.rs

1/// Helper to create a new `Device` instance.
2///
3/// Generates `get()`, `find()` and `list()` methods. Therefore are 5 parameters required:
4/// * `class_name: &str`
5/// * `driver_name: &str`
6/// * `port: dyn ev3dev_lang_rust::Motor`
7/// * `debug_name: &str`
8/// * `port_prefix: &str`
9///
10/// # Example:
11///
12/// ```ignore
13/// #[derive(Debug, Clone, Device)]
14/// pub struct LargeMotor {
15///     driver: Driver,
16/// }
17///
18/// impl LargeMotor {
19///     findable!("tacho-motor", "lego-ev3-l-motor", MotorPort), "LargeMotor", "out";
20///     tacho_motor!();
21/// }
22/// ```
23#[macro_export]
24macro_rules! findable {
25    ($class_name:expr, [$( $driver_name:expr ),*], $port: ty, $debug_name:expr, $port_prefix:expr) => {
26        fn map_error(e: Ev3Error) -> Ev3Error {
27            match e {
28                e @ Ev3Error::InternalError { .. } => e,
29                Ev3Error::NotConnected { device: _, port } => Ev3Error::NotConnected {
30                    device: $debug_name.to_owned(),
31                    port,
32                },
33                Ev3Error::MultipleMatches { device: _, ports } => Ev3Error::MultipleMatches {
34                    device: $debug_name.to_owned(),
35                    ports: ports
36                        .iter()
37                        .map(|item| <$port>::format_name(item))
38                        .collect(),
39                },
40            }
41        }
42
43        /// Try to get a `Self` on the given port. Returns `None` if port is not used or another device is connected.
44        #[allow(clippy::vec_init_then_push)]
45        pub fn get(port: $port) -> Ev3Result<Self> {
46            let mut driver_name_vec = Vec::new();
47            $(
48                driver_name_vec.push($driver_name);
49            )*
50
51            let name = Driver::find_name_by_port_and_driver($class_name, &port, &driver_name_vec)
52                .map_err(Self::map_error)?;
53
54            Ok(Self::new(Driver::new($class_name, &name)))
55        }
56
57        /// Try to find a `Self`. Only returns a motor if their is exactly one connected, `Error::NotFound` otherwise.
58        #[allow(clippy::vec_init_then_push)]
59        pub fn find() -> Ev3Result<Self> {
60            let mut driver_name_vec = Vec::new();
61            $(
62                driver_name_vec.push($driver_name);
63            )*
64
65            let name =
66                Driver::find_name_by_driver($class_name, &driver_name_vec).map_err(Self::map_error)?;
67
68            Ok(Self::new(Driver::new($class_name, &name)))
69        }
70
71        /// Extract list of connected 'Self'
72        #[allow(clippy::vec_init_then_push)]
73        pub fn list() -> Ev3Result<Vec<Self>> {
74            let mut driver_name_vec = Vec::new();
75            $(
76                driver_name_vec.push($driver_name);
77            )*
78
79            Ok(Driver::find_names_by_driver($class_name, &driver_name_vec)?
80                .iter()
81                .map(|name| Self::new(Driver::new($class_name, &name)))
82                .collect())
83        }
84    };
85}
ev3dev_lang_rust/findable.rs

ev3dev_lang_rust/
findable.rs
