//ww:run-exit 219
package main;
import encoding.utf8;
fn classify(d: *utf8.decoder) int = {
	match (utf8.next(d)) {
	case let r: rune => return 1;
	case let dn: utf8.done => return 2;
	case let m: utf8.more => return 3;
	case let e: utf8.invalid => return 4;
	};
	return 0;
};
export fn main() int = {
	let g: []u8 = [65u8];
	let dg = utf8.decode(g);
	let a = classify(&dg);
	let b = classify(&dg);
	let bad: []u8 = [255u8];
	let db = utf8.decode(bad);
	let c = classify(&db);
	let tr: []u8 = [195u8];
	let dt = utf8.decode(tr);
	let e = classify(&dt);
	return a * 1000 + b * 100 + c * 10 + e;
};