ctl10n

ctl10n (compile time localization) provides you a simple way to embed messages into binary file without embedding them into source. Internally, ctl10n generates simple macro_rules! macro tr!() from provided TOML file with strings.

Basic usage

Put following to your build.rs:

fn main() {
    println!("cargo:rerun-if-changed:build.rs");
    println!("cargo:rerun-if-chaged:strings.toml");
    if let Err(err) = ctl10n::convert_default_strings_file() {
        panic!("{}", err);
    }
}

This will generate file $OUT_DIR/strings.rs from strings.toml. TOML file with strings must be table where all values are strings. Example strings.toml:

message = "Some message"
message-with-args = "Some message with {arg}"

You should include strings.rs somewhere (for example, in lib.rs) to use generated macro. You can do this by calling macro ctl10n::include_strings!() or manually, using include!(). After including macro it can be used like this:

ctl10n::include_strings!();

fn main() {
    // `tr!()` with one argument will be translated to string literal
    println!(tr!("message"));
    println!(tr!("message-with-args"), arg = "foobar");
    // `tr!()` with multiple arguments will be translated to formatted `&String`
    println!("{}", tr!("message-with-args", arg = "foobaz"))
}

Output of this code (assuming strings.toml from above):

Some message
Some message with foobar
Some message with foobaz

Trying to use unknown key or wrong format arguments is compile-time error.