Split mixed upper and lowercase in the same word into two lines - regex

Question

I have a string in cells that is lacking new lines.
It looks like this:
Text Text TextText Text Text T5df Tdfcv TextNeu
In other words:
If there is a change from Lowercase to Uppercase within a word, this is where a new line should be inserted as \n.
So the example would convert to
Text Text Text
Text Text Text T5df Tdfcv Text
Neu
Resp.:
Text Text Text\nText Text Text T5df Tdfcv Text\nNeu
I found
String[] r = s.split("(?=\\p{Lu})");
I tried REGAUS(F2;"(?=\\p{Upper})";"\n";"g") yet I get a 502, as something is wrong with the regex.
Which formula do I need for calc to do this?

Answer 1

With english formula names, the following formula will do the trick:
=REGEX(A1;"([:lower:])([:upper:])";"$1"&CHAR(10)&"$2";"g")
Same on multiple lines for sake of readability:
=REGEX(
A1;
"([:lower:])([:upper:])";
"$1" & CHAR(10) & "$2";
"g"
)
It matches a lower-case letter followed by an upper-case letter, and inserts a newline using the CHAR() function.
You'll have to adapt the line heigth manually, otherwise you will see only "Neu" (the last line).
For localised formula names (german), it would be:
=REGAUS(A1;"([:lower:])([:upper:])";"$1"&ZEICHEN(10)&"$2";"g")
I would have expected that inserting "\n" should work, too, but i did'nt manage got get it working, thus the recourse to CHAR(10).