[lexicality]

What do you mean by "exactly" though? What is the "exact" value of "e"? 0x65? How about "é"? You expect your editor to take what you've written and provide a valid text file with that information in it, which can then be read by something else. Applying the correct text encoding (UTF-8?) and adding a 0x0A as the last byte are part of making it valid.

If you want to specify the exact bytes on disk, you should use a hex/bin editor.

[Sniffnoy]

The correct text encoding is the one I specify. UTF-8 is a decent default. Where did that bit about 0x0A come from? That's just an extra byte. There's no text encoding that says "to decode this you should first remove the 0x0A at the end, which is not part of the text".

I should only need a hex editor if I want to make a file that can't be decoded as text under a known encoding, and no encoding I know (and certainly none that I use) has the encoding/decoding rule I mentioned above. I certainly shouldn't need one just to make a validly-encoded UTF-8 file that happens to end in a character other than a newline.

Basically, either it's part of the encoding or it's part of the text, and if it's part of the text, I ought to be able to control it. And it isn't part of the encoding.