axconfig-macros

Procedural macros for converting TOML format configurations to equivalent Rust constant definitions.

Example

axconfig_macros::parse_configs!(r#"
are-you-ok = true
one-two-three = 123

[hello]
"one-two-three" = "456"     # int
array = [1, 2, 3]           # [uint]
tuple = [1, "abc", 3]
"#);

assert_eq!(ARE_YOU_OK, true);
assert_eq!(ONE_TWO_THREE, 123usize);
assert_eq!(hello::ONE_TWO_THREE, 456isize);
assert_eq!(hello::ARRAY, [1, 2, 3]);
assert_eq!(hello::TUPLE, (1, "abc", 3));

Value types are necessary for generating Rust constant definitions. Types can be specified by the comment following the config item. Currently supported types are bool, int, uint, str, (type1, type2, ...) for tuples, and [type] for arrays. If no type is specified, it will try to infer the type from the value.

The above example will generate the following constants:

pub const ARE_YOU_OK: bool = true;
pub const ONE_TWO_THREE: usize = 123;

pub mod hello {
    pub const ARRAY: &[usize] = &[1, 2, 3];
    pub const ONE_TWO_THREE: isize = 456;
    pub const TUPLE: (usize, &str, usize) = (1, "abc", 3);
}

You can also include the configuration file directly:

axconfig_macros::include_configs!("path/to/config.toml");
// or specify the config file path via an environment variable
axconfig_macros::include_configs!(path_env = "AX_CONFIG_PATH");
// or with a fallback path if the environment variable is not set
axconfig_macros::include_configs!(path_env = "AX_CONFIG_PATH", fallback = "path/to/defconfig.toml");