To some extent, I think it's reasonable. PHP had the same issue (old libraries assuming single byte strings) and the way they handled it is pretty awful. Essen

To some extent, I think it's reasonable. PHP had the same issue (old libraries assuming single byte strings) and the way they handled it is pretty awful. Essentially all string manipulation functions also have an equivalent function with the same name prefixed with "mb_", which works for multibyte strings. The practical effect is that people use the default string functions and then things break when multibyte strings start showing up! It is backward compatible, but it's certainly ugly and that's quite a tradeoff.