You forget to mention the other side of the trade-off: a hash trades memory for speed. grep will run in O(N), but also consume a lot less memory. It also requires a certain amount of work to set up the hash; if you're only going to test a particular set few times, it may well end up not amortizing that up front effort.

TANSTAAFL.

Makeshifts last the longest.

In reply to Re^3: writing perl function like sql IN by Aristotle
in thread writing perl function like sql IN by JAMBOID

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