INFRA - Config parsing

[TomLonergan03]

An unwise man has produced a yaml to rust transpiler because lmao. It is on crates.io (source here) should you ever need it.

what it does:
turns this

parsing: "working"
age: 22
enabled: true
time: 22.34
recurse:
  thing: 1
  recurse:
    thing: 3
array: ["a", "b", "c"]
empty_array: []
array_of_arrays:
  - ["a", "b", "c"]
  - ["d", "e", "f"]
array_of_objects:
  - name: "a"
    age: 1
  - name: "b"
    age: 2
  - name: "c"
    age: 3

into

struct Config {
    pub parsing: &'static str,
    pub age: i64,
    pub enabled: bool,
    pub time: f64,
    pub recurse: ConfigRecurse,
    pub array: [&'static str; 3usize],
    pub empty_array: [(); 0usize],
    pub array_of_arrays: [[&'static str; 3usize]; 2usize],
    pub array_of_objects: [ConfigArrayOfObjects; 3usize],
}

struct ConfigRecurse {
    pub thing: i64,
    pub recurse: ConfigRecurseRecurse,
}

struct ConfigRecurseRecurse {
    pub thing: i64,
}

struct ConfigArrayOfObjects {
    pub name: &'static str,
    pub age: i64,
}

pub const CONFIG: Config = Config {
    parsing: "working",
    age: 22i64,
    enabled: true,
    time: 22.34f64,
    recurse: ConfigRecurse {
        thing: 1i64,
        recurse: ConfigRecurseRecurse { thing: 3i64 },
    },
    array: ["a", "b", "c"],
    empty_array: [],
    array_of_arrays: [["a", "b", "c"], ["d", "e", "f"]],
    array_of_objects: [
        ConfigArrayOfObjects {
            name: "a",
            age: 1i64,
        },
        ConfigArrayOfObjects {
            name: "b",
            age: 2i64,
        },
        ConfigArrayOfObjects {
            name: "c",
            age: 3i64,
        },
    ],
};

you can now access config values by doing

// items in a hashmap
assert_eq!(CONFIG.parsing, "working");

// items in a list
assert_eq!(CONFIG.array[1], "b");

// nested hashmaps
assert_eq!(CONFIG.recurse.recurse.thing, 3);

all your favourite rust types are here (if those are i64/f64/&'static str/bool)! and because of const, it all gets inlined at compile time so your billion line yaml file gets optimised down to only the exact values you care about (i think)

two restrictions:

• arrays of things: everything in an array must be the same type
• keys: names of entries must not use rust reserved words, most likely no type is the main restriction here but also for, struct, etc.

also i 100% broke telemetry by changing the field names lol

[TomLonergan03]

huh i gotta figure out how to do the config file path for the nested boards. will push a new version tomorrow maybe

[davidbeechey]

very epic, can merge once the board code is fixed

[arjunnaha]

The non-Rust contingent of the Edinburgh Hyperloop Team, otherwise known as the telemetry team, approves :)

My kindest ever regards,
Mr. Arjun Naha
(Soon to be) Bachelors of Engineering from The University of Edinburgh, Influencing the world since 1583

[TomLonergan03]

Am setting an env var in build.rs, which is used to set the config path.

The other option i have working is using nightly to use Span if you enable the feature relative-to-macro, which then will use a path relative to the macro invocation, which means it works with the board builds