There is something, added to 5.8, that could help catch the "typo"s from happening. I've been a lurker on the perl5-porters mailing list, and one of the more fascinating discussions I read about, back when I was actually able to take time to read that list, was an idea about creating "clamped" hashes. The idea was to help eliminate accidentally creating hash keys, but it grew from there.

The current implementation has been made a core module called Hash::Util, you can read about it here.

In an attempt to quickly summarize what you'll find at the link above, the following methods are available:

Method Description
lock_keys(%hash)don't allow any keys other than what currently exists
lock_keys(%hash,@keys)dont allow any keys other than those in the array @keys
unlock_keys(%hash)unlock the hash to be able to add keys
lock_value(%hash,$key)Keep the value at $hash{$key} from being changed
unlock_value(%hash,$key)Allow the value to change
lock_hash(%hash)don't allow keys or values to change
unlock_hash(%hash)allow keys and values to change

-Scott

In reply to Re: The Bad, the Ugly, and the Good of autovivification by 5mi11er
in thread The Bad, the Ugly, and the Good of autovivification by tlm

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