Feature Proposal: General Sorting Mechanism for TWiki

Motivation

Currently:

• Each module and plugin has its own sort functions
• Lists are often not sorted case-insensitive because of fear of performance loss, resulting in (for humans) strange word order (see for example Bugs:Item2135)
• Key sort can be made more efficient

It would be useful to have one sorting mechanism that core code and plugins can use. This core sort code can be tested.

Proposal

Add a sorting lib to the distributed CPAN directory.

Description and Documentation

I was triggered by A Fresh Look at Efficient Perl Sorting. It is a widely quoted paper that has resulted in CPAN:Sort::Maker - A simple way to make efficient sort subs.

I can see 2 alternatives to use:

• CPAN:Sort::Maker
• CPAN:Sort::Key

More info on sorting

• CPAN:Sort::External for sorting huge lists - Problem: You have a list which is too big to sort in-memory. Solution: "feed, finish, and fetch" with Sort::External, the closest thing to a drop-in replacement for Perl's sort() function when dealing with unmanageably large lists.
  • Sort::External::Cookbook

-- Contributors: ArthurClemens

Discussion

I will investigate how the two libraries perform.

-- ArthurClemens - 26 Oct 2008

Decided at HelsinkiReleaseMeeting2009x04x20 to park this proposal until use case understood and owner found.

-- PeterThoeny - 2009-04-20

Use cases:

• IP addresses (e.g., see FormattingIp)
• I have added priorities of 'High', 'Medium', 'Low' to my installation of Action tracker. They don't sort well either unless I prefix a number.
• Last but not least: sort on multiple table columns! (e.g., SearchOrderOnMoreColumns)

-- SeanCMorgan - 2009-04-21