Re: Hash key string restrictions?[THANKS]

[Ojosh!ro]

Thank you all very much. This is the answer I hoped for.
As to the purpose of the question:
I was experimenting with eval and wondered if I could put sub-references in a hash to prevent double evals.
(the mechanism behind it would check the existence of the to-be-evalled string and simply return a reference to the sub-ref in question if it existed and otherwise make a new pair )

I have no clue of whether such a mechanism already exists under perl's shiny bonnet.

[ikegami]

Yup! Assuming the evaled code returns a code ref,

my $code_ref = $code_cache{$code} ||= eval $code;
die("Unable to compile and run code: $@\n)"
   if !$code_ref;
$code_ref->();

[Ojosh!ro]

That was the basic idea,
( the ||= eval $code part would also be stored in the %code_cache )

[ikegami]

The statement I provided *does* store the result in %code_cache. Note the usage of ||= instead of ||.