Nice solution! But a couple of questions:

It would be interesting to benchmark if using unshift() into the $hashrefs array would be more or less efficient than messing with $i. If nothing else, it would be two lines shorter, and more Perlish.

And perhaps this is too early in the morning, but why are you splicing by -4, and then popping @data?

It's Sunday morning where I am, and I'm too lazy to try to write a coherent benchmark...

--Chris

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