As pre­vi­ous­ly writ­ten, I like list pro­cess­ing. Many com­put­ing prob­lems can be bro­ken down into trans­form­ing and fil­ter­ing lists, and Perl has got the fun­da­men­tals cov­ered with func­tions like map, grep, and sort. There is so much more you might want to do, though, and CPAN has a pletho­ra of list and array pro­cess­ing modules.

However, due to the vicis­si­tudes of Perl mod­ule main­te­nance, we have a sit­u­a­tion where it’s not clear at a glance where to turn when you’ve got a list that needs pro­cess­ing. So here’s anoth­er list: the list mod­ules of CPAN. Click through to dis­cov­er what func­tions they provide.

• We’ve got List::Util which has been released as part of Perl since ver­sion 5.7.3.
• We’ve got List::MoreUtils which has some func­tions which are named the same as Util but behave differently.
• We’ve got List::SomeUtils which dupli­cates MoreUtils but with few­er dependencies.
• We’ve got List::UtilsBy which MoreUtils has also cribbed some func­tions from.
• We’ve got List::AllUtils which attempts to con­sol­i­date Util, SomeUtils, and ListBy but has some excep­tions to called mod­ules because of the afore­men­tioned dupli­ca­tion between Util and SomeUtils.
• We’ve got List::Util::MaybeXS which helps with pure Perl fall­backs in case your ver­sion of Util is too old to have a cer­tain function.
• We’ve got List::MoreUtils::XS which pro­vides (some?) faster ver­sions of MoreUtils’ func­tions (but you still have to use MoreUtils).
• And last­ly, we have Util::Any which lets you import func­tions from Util, MoreUtils, and just for good mea­sure Scalar::Util, Hash::Util, String::Util, String::CamelCase, List::Pairwise, and Data::Dumper. But it has­n’t been updat­ed since 2016, so it does­n’t nec­es­sar­i­ly export the func­tions added to those mod­ules since then.

Am I miss­ing any­thing? Probably! But these are the ones most asso­ci­at­ed with being upstream on the CPAN River, so they (or the mod­ules they con­sol­i­date) have more projects depend­ing on them.