RFC: use "unknown character" as default Char

[joneugster]

Proposal

Unicode has a dedicated character meaning "unknown character": '\uFFFD'

Currently String.get returns "A" as default value, which might be a tiny bit unexpected and certainly an arbitrary choice.
In my opinion '\uFFFD' would be a slightly better choice.

• User Experience: How does this feature improve the user experience?
  It might be slightly more understandable if they see '\uFFFD' instead of a random 'A'.
  If a user does s.get ⟨1⟩ where ⟨1⟩ is an invalid String.Pos, they get A returned, which might be confusing

• Maintainability: Will this change streamline code maintenance or simplify its structure?
  should have no impact on maintainability.

Community Feedback

Impact

Add 👍 to issues you consider important. If others benefit from the changes in this proposal being added, please ask them to add 👍 to it.

[nomeata]

Thanks for the suggestion. I agree in spirit, but I'm not sure if this is the most pressing issue we have at the moment, given all the other things we could fix and the limited developer attention resources.

Also slightly worried that users will be confused to see a character that doesn't render nicely in whatever font they are using.

If you feel strongly about it (and its not just a ”sure why not change”) I suggest to just do it without much more discussion. Else maybe let's focus on other things that are more than “slightly better”, at least for now.

[joneugster]

ok, sorry for the bother! The default char might be refelected in teh C code, so this seems too much effort.

I'll resort to using myString.get? pos |>.getD '\uFFFD' instead. (and might PR the missing String.getD at some point)