fig

A simple configuration language

Syntax

Fig currently supports the following expression types:

Type	Examples
Bool	true, false
Number	123, 45.6, 7e8
Ident	x, x2, an_ident
Str	"Hello, world"
List	[1, 2, 3]
Map	{x: 1, y: 2}

with a limited form of evaluation that just looks up Ident expressions in the global environment. Watch out for spaces! [ 1, 2, 3] is currently invalid, for example, but [1,2,3] should be fine.

Usage

The intended usage of Fig is through the Fig::parse function. This will parse a &str as a Fig program and return a Fig struct, which is currently a thin wrapper around a HashMap<String, Value>. You'll likely want to do some type checking on the Values and assemble some kind of Config struct. For example:

use fig::Fig;

struct Config {
    x: usize,
}

impl From<Fig> for Config {
    fn from(value: Fig) -> Self {
        Self {
            x: *value.variables.get("x").unwrap().as_number().unwrap() as usize,
        }
    }
}

#[test]
fn main() {
    let s = "
        let x = 1;
    ";
    let f = Fig::parse(s).unwrap();
    let conf = Config::from(f);
}