utf8 iterator

import unicode

iterator utf8(str: string): string =
  var offset = 0
  while offset < str.len:
    let len = runeLenAt(str, offset)
    yield str[offset.. (offset+len-1)]
    offset += len

let text = "Öhm? 漢兩秦先"

for c in text.utf8:
  write stdout, c & " "