for i, w := 0, 0; i < len(value); i += w {
w = width(value[i])
followed_by_whitespace = i+w >= len(value) || is_blank(value, i+w)
for i, w := 0, 0; i < len(value); i += w {
w = width(value[i])
followed_by_whitespace = i+w >= len(value) || is_blank(value, i+w)