Sanity is subjective here. There are reasons to disallow non-ASCII characters, for example to prevent identical-looking characters from causing sneaky bugs in the code, like this but unintentional: https://en.wikipedia.org/wiki/IDN_homograph_attack (and yes, don’t you worry, this absolutely can happen unintentionally).
OCaml’s old m17n compiler plugin solved this by requiring you pick one block per ‘word’ & you can only switch to another block if separated by an underscore. As such you can do print_แมว but you couldn’t do pℝint_c∀t. This is a totally reasonable solution.
I can’t imagine how something like homograph attacks can happen accidentally. If someone does this in code, they probably intended to troll other contributors.
Multilingual users have multiple keyboard layouts, usually switching with Alt+Shift or similar key combo. If you’re multitasking you might not realize you’re on the wrong keyboard layout. So say you’re chatting with someone in Russian, then you alt+tab to your source code and you spot a typo - you wrote my_var_xopy instead of my_var_copy. You delete the x and type in c. You forget this happened and you never realized the keyboard layout was wrong.
That c that you typed is now actually с, Cyrillic Es.
I use multilingual keyboard layouts, so I know that at least on Windows the selected layout is specific to each window. If I chat with someone in one language, then switch to my IDE, it will not keep the layout I used in the chat window.
But I also have accidently hit the combination to change layouts while doing something, so it can happen. I’m just surprised that Cyrillic с is on the same key as C, instead of S.
I believe there’s a setting for whether it’s global or per-window. Personally I prefer global, because I can’t keep track of more than one state and I absolutely hate the experience of typing something and getting a different language than you expect.
Sanity is subjective here. There are reasons to disallow non-ASCII characters, for example to prevent identical-looking characters from causing sneaky bugs in the code, like this but unintentional: https://en.wikipedia.org/wiki/IDN_homograph_attack (and yes, don’t you worry, this absolutely can happen unintentionally).
OCaml’s old m17n compiler plugin solved this by requiring you pick one block per ‘word’ & you can only switch to another block if separated by an underscore. As such you can do
print_แมวbut you couldn’t dopℝint_c∀t. This is a totally reasonable solution.That’s pretty cool
I can’t imagine how something like homograph attacks can happen accidentally. If someone does this in code, they probably intended to troll other contributors.
Multilingual users have multiple keyboard layouts, usually switching with Alt+Shift or similar key combo. If you’re multitasking you might not realize you’re on the wrong keyboard layout. So say you’re chatting with someone in Russian, then you alt+tab to your source code and you spot a typo - you wrote
my_var_xopyinstead ofmy_var_copy. You delete the x and type in c. You forget this happened and you never realized the keyboard layout was wrong.That c that you typed is now actually с, Cyrillic Es.
What do you say, is that realistic enough?
I use multilingual keyboard layouts, so I know that at least on Windows the selected layout is specific to each window. If I chat with someone in one language, then switch to my IDE, it will not keep the layout I used in the chat window.
But I also have accidently hit the combination to change layouts while doing something, so it can happen. I’m just surprised that Cyrillic с is on the same key as C, instead of S.
I believe there’s a setting for whether it’s global or per-window. Personally I prefer global, because I can’t keep track of more than one state and I absolutely hate the experience of typing something and getting a different language than you expect.