in reply to Secret Perl Operators: the boolean list squash operator, x!!
Comparing:
( list ) x!! cond ( grep cond, list ) cond ? ( list ) : ()
I think I'd rather "reuse" the well-known grep for this case than adopt the more cryptic idiom you've invented. For your example case, I much prefer something that uses:
join '/', grep defined $_, ...
Rather than repeating most of the terms twice (and repeating x!! and defined).
- tye
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