2. The fastest factorial implementation is a lookup table. The next fastest (in pure perl) is an iterative scheme.

3. As the aforementioned node demonstrated, tail call recursion isn't all that fast in the current perl5. Speeding it up probably requires hacking on the core. If you need to compute factorials repeatedly in a recursive fashion, consider using memoization. Memoization builds a lookup table that could even beat the iterative scheme in certain situations.

-Mark

In reply to Re: What is the fastest pure-Perl implementation of XXX? by kvale
in thread What is the fastest pure-Perl implementation of XXX? by dragonchild

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