alt Hacker NewsThe reason this is so is that there is no way to say "the library accepts UTF-32, for other encodings use the standard decoder" because there is no such a decoder. "For want of a nail". So it circles back to the idea of easily composable software which is not yet there. Everybody bring their own nails and there is no way to move nails between projects.
What do you mean that there is no standard decoder? For what, UTF-8?
I agree on the composability. Accepting Unicode code points is more generic. I guess it depends on your environment. If every caller will combine it with a UTF-8 decoder, you might want to include it.