//! Implements format string evaluation in weak Conlang


/// Formats a string
fn f(__fmt: &str) -> &str {
    let __out = "";
    let __expr = "";
    let __label = "";
    let __depth = 0;
    for __c in chars(__fmt) {
        match __c {
            '{' => {
                __depth += 1
                if __depth <= 1 {
                    continue
                }
            },
            '}' => {
                __depth -= 1
                if __depth <= 0 {
                    __out = fmt(__out, __label, eval(__expr));
                    (__expr, __label) = ("", "");
                    continue
                }
            },
            ':' => if __depth == 1 && __label.len() == 0 {
                __label = __expr + __c
                continue
            },
            '=' => if __depth == 1 && __label.len() == 0 {
                __label = __expr + __c
                continue
            },
            _ => {}
        }
        match (__depth, __label.len()) {
            (0, _) => __out += __c,
            (_, 0) => __expr += __c,
            (_, _) => __label += __c,
        }
    }
    __out
}