I was just going to ask about substrings, and then didn't because I
figured that had been hashed out already and I'd missed it...

It would be possible to have right-associative operators (that bind at
least more tightly than comma and possibly very tightly) and convert a
number to one of these objects, so that we can do stuff like this:

substr($string, 2 bytes, 4 bytes) = $substitute;

Then if you pass a plain number to substr it could either assume
something (possibly generating a warning) or spit an error, depending
on some feature of the current lexical scope.

The word "bytes" is clearly much too long, though, much less
"graphemes" or "codepoints".  I thought about this:

substr($string, 2b, 4b) = $substitute;

With presumably g and c for graphemes and codepoints, but I rather
suspect that might conflict with some other existing syntax (though I
can't think of anything in particular).

And I can't think of another abbreviation that would be remotely
intuitive.

There's also the possibility of bsubstr and so on, but that leads us
down the path of C, having a hillion bajillion functions with names
like fgets, stoi, and fstrnclost.  Having sprintf is quite enough of
that, IMO.

codes and graphs is better than codepoints and graphemes, at least.

You could coin the abbreviation ligs, for Language Independent
Graphemes.  Then some ingenious rascal can create a pragma or whatever
that allows $str.b, $str.c, $str.g, and $str.l for fans of terseness.

--
$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
split//,"ten.thgirb\@badanoj$/ --";$\=$ ;-> ();print$/