sort(3p) Perl Programmers Reference Guide sort(3p) #

sort(3p) Perl Programmers Reference Guide sort(3p)

NNAAMMEE #

 sort - perl pragma to control sort() behaviour

SSYYNNOOPPSSIISS #

 The sort pragma is now a no-op, and its use is discouraged. These three
 operations are valid, but have no effect:

     use sort 'stable';          # guarantee stability
     use sort 'defaults';        # revert to default behavior
     no  sort 'stable';          # stability not important

DDEESSCCRRIIPPTTIIOONN #

 Historically the "sort" pragma you can control the behaviour of the
 builtin "sort()" function.

 Prior to v5.28.0 there were two other options:

     use sort '_mergesort';
     use sort '_qsort';          # or '_quicksort'

 If you try and specify either of these in v5.28+ it will croak.

 The default sort has been stable since v5.8.0, and given this consistent
 behaviour for almost two decades, everyone has come to assume stability.

 Stability will remain the default - hence there is no need for a pragma
 for code to opt into stability "just in case" this changes - it won't.

 We do not foresee going back to offering multiple implementations of
 general purpose sorting - hence there is no future need to offer a pragma
 to choose between them.

 If you know that you care that much about performance of your sorting,
 and that for your use case and your data, it was worth investigating
 alternatives, possible to identify an alternative from our default that
 was better, and the cost of switching was worth it, then you know more
 than we do. Likely whatever choices we can give are not as good as
 implementing your own. (For example, a Radix sort can be faster than O(n
 log n), but can't be used for all keys and has larger overheads.)

 We are not averse to cchhaannggiinngg the sort algorithm, but we don't see the
 benefit in offering the choice of two general purpose implementations.

CCAAVVEEAATTSS #

 The function "sort::current()" was provided to report the current state
 of the sort pragmata. This function was not exported, and there is no
 code to call it on CPAN. It is now deprecated, and will warn by default.

 As we no longer store any sort "state", it can no longer return the
 correct value, so it will always return the string "stable", as this is
 consistent with what we actually have implemented.

perl v5.36.3 2023-02-15 sort(3p)