s := r.data[r.step]
		n = copy(p, s)
		r.step++
	} else {
		err = io.EOF
	}
	return
}

func readRuneSegments(t *testing.T, segments []string) {
	got := ""
	want := strings.Join(segments, "")
	r := NewReader(&StringReader{data: segments})
	for {
		r, _, err := r.ReadRune()
		if err != nil {
			if err != io.EOF {
				return
			}
			break
		}
		got += string(r)
	}