The Best Practices have things to say about many of Perl’s built-in functions. Besides the general advice “use them” – which I agree with – it has some specific suggestions. First up: Sorting
The advice given by the PBP regarding sort is not to do complex calculations in the sort function. That function will be called many times, often calling with a value it has used before. If you’re doing a complex calculation – say a checksum or other hash – you should cache those calculated values and use the cache. The PBP has a clear example of this.
It also suggests you could use a Schwartzian Transform to build pre-calculated values, sort on them, then clean up the temporary values.
The third suggestion isn’t made as often, but is quite interesting, and uses a module called Memoize to “memoize” the hash function, which means it will only call it once and store the values – another way of caching.
I agree with the suggestion to avoid complex work when possible in the sort function, as it is called frequently. Any of these are fine suggestions.