Sorry, Higher Order Perl is a book on functional programming in perl, by SchwernDominus, the author of the Memoize module.

In my experimentation, Memoize has shown quite high overhead. A general solution like that has to impose the cost of a separate sub call, as well as handling all sorts of parameters (e.g. differentiating between undef and "") and caching separately for scalar/list/void context.

In most cases I've run into, the simple inline scalar caching is sufficient and not too burdensome to insert. Throwing list context into the mix complicates things a lot.

Update: I really do know the difference between Schwern and Dominus, no idea what bizarre neural connection led me to get that wrong.