Re: Unicode in strings

Assume you're implementing a language which has a function of setting
an individual character in a string.

That's a design mistake in the language, and I know no language that
has this misfeature.

I suspect "individual character" meant "code point" above.
Does Unicode even has the notion of "character", really?

Instead, what we see is one language (Python3) that has an even worse
misfeature: You can set an individual code point in a string; see
above for the things you get when you overwrite code points.

I think it's fairly common for languages that started with strings
as "arrays of 8bit chars".

Emacs Lisp has this misfeature as well (and so does Common Lisp).  🙁
It's really hard to get rid of it, even though it's used *very* rarely.
In ELisp, strings are represented internally as utf-8 (tho it pretends
to be an array opf code points), so an assignment that replaces a single
char can require reallocating the array!

But why would one want to set individual code points?

Because you know your string only contains "characters" made of a single
code point?

E.g. your string contains the representation of the border of a table
(to be displayed in a tty), and you want to "move" the `+` of a column
separator (or a prettier version that takes advantage of the wider
choice offered by Unicode).


        Stefan