The documentation is quite clear: In scalar context, the reverse function operates on strings
You're once again trying to make some esoteric point about the distinction between strings and bytes,
No. Quite the opposite, I'm saying there is no distinction. reverse doesn't know or care what the string is, and has no way of knowing. It will reverse the characters (elements?) of the string.
What is a character in a language is well-understood and rarely, if ever, subject to debate
You opened the debate! Again, a common CS definition is used here: A string is a sequence of elements named characters. Would you care to suggest an alternative?
What is a character in a language is well-understood and rarely, if ever, subject to debate. In the case of Unicode, "character" is well-defined, too: It's a "grapheme." It's as simple as that. Read the Unicode Standard.
Unicode has four definitions for "character", and none correspond exactly to that of "grapheme".
But it's irrelevant. Again, reverse function isn't to manipulate text.
There are four characters in the word "Café", not five.
Yes, but irrelevant. reverse's function isn't to manipulate words. There are five characters in the string chr(0x43).chr(0x61).chr(0x66).chr(0x65).chr(0x301).
Your insistence that there's a difference between "string" and "text" may have some strange basis in the arcane details of the internals of Perl,
Again, quite the opposite. It has nothing to do with Perl internals. It's not even specific to Perl. A string is a data type. Text is one of many things that can be stored in a string.
my $x = "abcd"; # String? yes. Text? my $host = inet_ntoa($x); # No, "packed" IP address
my $x = "abcd"; # String? yes. Text? print("The password is $x\n"); # Yes.
You're suggesting that Perl should reverse strings as if they're text. For example, you say
But that's wholly inappropriate for water level measurements or for anything else the string might be.
There is need for a function that reverses strings (chr(101).chr(769) ⇒ chr(769).chr(101)). There is also a need for a function that reverses text (chr(101).chr(769) ⇒ chr(101).chr(769)). reverse does the former.