Yes, but have you _seen_ the bickering about the existing bracket
choices just for frozenset? Eww. Hence the going for a distinct operator
altogether. Yes, I'd prefer brackets of some kind too, but they're
taken.
If one uses prefixes, you start from 53 valid (all latin areas, upper, lower and @)
new brackets for {} .
I can't see how they are "all taken" when the strongest argument against
prefixing seems to be "but _only strings_ should have prefixes".
(with the "typing f{} instead of f() is going to be a bug magnet"
as a runner up). None of those stand up to any logical analysis
It is ok voting that "the language should not be made more complex
at this point, and we won't add any new syntax for a frozenset", but
I think that if it is agreed that frozensets are ok, a prefix
is just straightforward.
And then, adopting prefixes for curly braces, you have 52 other
bracket types to try and sell this "generic freezer operator"
you are presenting here. :-).