decode_fixed/decode_fixed.rs
use codex_percent::FixedDecoder;
fn main() {
let s = "%F0%9F%92%A9";
let mut d = FixedDecoder::<4>::init();
let res = d.decode(s).unwrap();
assert_eq!(res, 4);
let t = core::str::from_utf8(d.cur_block().as_slice());
assert_eq!(t, Ok("💩"));
println!("{} -> {}", s, t.unwrap());
}