in reply to Making a failed hash lookup return something other than undef

You could use a tied hash where FETCH checks that the key exists before returning it. If it doesn't exist, it returns a default value (perhaps supplied when you called tie. All the other tied hash methods access the internal hash directly.

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I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

: () { :|:& };:

Note: All code is untested, unless otherwise stated

In Section Seekers of Perl Wisdom