The documentation states, that string-upcase "uses Unicode’s locale-independent conversion rules".
And, that for current-locale
when locale sensitivity is disabled by setting the parameter to #f, strings are compared, etc., in a fully portable manner, which is the same as the standard procedures.
But it doesn't work for me (Racket 8.9-cs, Window-x64). What value should I set to current-locale, to get "STRASSE" from string-locale-upcase?
Isn’t this a special case of ‘Rechtschreibung’ in German? Technically Strasse is wrong (my remote recollection) and German considers the letter in STRAßE an uppercase s-z. (Don’t blame me. I have only one passport and it’s a US passport I suspect @Mike Sperber knows better .. he was a professor in Germany.
Seit dem 29. Juni 2017 ist das große ß (ẞ) offiziell Bestandteil der amtlichen deutschen Rechtschreibung.[10][11] Damit ist seither zum Beispiel die Schreibweise STRAẞE gleichberechtigt neben der Schreibweise STRASSE zulässig.