F url_encode(s)
   V r = ‘’
   V buf = ‘’

   F flush_buf() // this function is needed because strings in 11l are UTF-16 encoded
      I @buf != ‘’
         V bytes = @buf.encode(‘utf-8’)
         L(b) bytes
            @r ‘’= ‘%’hex(b).zfill(2)
         @buf = ‘’

   L(c) s
      I c C (‘0’..‘9’, ‘a’..‘z’, ‘A’..‘Z’, ‘_’, ‘.’, ‘-’, ‘~’)
         flush_buf()
         r ‘’= c
      E
         buf ‘’= c

   flush_buf()
   R r

print(url_encode(‘http://foo bar/’))
print(url_encode(‘https://ru.wikipedia.org/wiki/Транспайлер’))