Most *nix filesystems permit paths to be any NUL-terminated C string with a special meaning for the slash character. That's why you can't represent them with Unicode strings. This is not an issue with UTF-8. You can't represent them as UTF-16 or UTF-32 either. You're very wrong.
Conversation
Replying to
What's specifically wrong with the slash character in a path? At least for UTF8, slash is in the first 128 characters (since slash exists in ASCII as well).
Semantically, it carries additional info, but I don't see what's wrong w/ storing it in a UTF8 string.
1
Replying to
It's not a problem. I was explaining that the restrictions on what can be in a path stop far short of allowing only valid Unicode. UTF-8 works fine as the encoding for *nix paths but there's nothing stopping anyone from using any other byte strings without internal \0 characters.
1
I just mentioned slash because the special meaning means a filename can't contain either NUL or slash unlike a path as a whole which just can't contain NUL.
Unicode permits NUL inside strings so not every Unicode strings can be converted in a lossless way to a path either.
This Tweet was deleted by the Tweet author. Learn more
Should ideally avoid becoming a problem elsewhere and should be solved for JavaScript. They could add a document/program wide mode where valid Unicode strings are enforced and then people can opt-out of the problem. Can require it to use new features like they often do with TLS.
1
I don't really think they need new APIs or API redesign to fix JavaScript's Unicode issues. Need a way to opt-out of legacy strings. In practice, not much would break, and the breakage would be a nice way of uncovering a lot of latent bugs that are potentially already serious.
1
It would then be using UTF-16, which is still unfortunate due to wasted memory, engine complexity from optimizations to avoid wasting as much memory, conversion overhead, etc.
Separate feature could be adding a nice new string type using UTF-8 and requiring the Unicode mode.
1
It really wouldn't be that hard to just turn JavaScript strings into UTF-16 in where you opt-in with either an equivalent to "use strict" (globally or not at all) or via document metadata like a header.
It'd be nice to give it a modern immutable UTF-8 string type but not needed.
This Tweet was deleted by the Tweet author. Learn more
It shouldn't be possible for anything involving strings rather to end up containing invalid Unicode. With that properly enforced, most of the problems go away. When converting from arbitrary bytes, you can choose multiple approaches and it's already an existing choice.
This is already a serious problem whenever JavaScript has to interact with the outside world. Anything reasonable enforces valid Unicode for strings. Interoperability issues are entirely on the JS side and it's not everyone else's problem to support the screwed up legacy strings.
This Tweet was deleted by the Tweet author. Learn more
Show replies