## Forum archive 2000-2006

### Barbra Bannon - Perl Sort function

by Arnold Pizer -
Number of replies: 0
 Perl Sort function topic started 10/26/2001; 12:36:59 PMlast post 10/26/2001; 12:55:57 PM
 Barbra Bannon - Perl Sort function  10/26/2001; 12:36:59 PM (reads: 3457, responses: 1) I'm trying to sort a simple array using the PERL sort function. @a = ($h,$k,$l); @a1 = sort {$a <=> $b} @a; The error webworks is giving me is the following: sort trapped by operation mask at (eval 50) line 72. Can you help me? -Barbra Bannon <| Post or View Comments |>  Michael Gage - Re: Perl Sort function 10/26/2001; 12:55:57 PM (reads: 3699, responses: 0) This is in PGbasicmacros.pl, but hasn't received documentation yet -- you have to look at the source code. sub lex_sort { PGsort sub {$_[0] cmp $_[1]}, @_; }sub num_sort { PGsort sub {$_[0] <=> \$_[1]}, @_;} Use it like this:  @out_array = lex_sort(@array); will sort the array lexigraphically  @out_array = num_sort(@array); will sort it numerically. PGsort is defined in PGtranslator.pm if you want to do something more esoteric. sort can be used to hang the execution of a problem, so we have made it available only through the PGsort alias. At the moment PGsort doesn't actually do much to protect against abuse, but the hook is there to install a time out or some other protection if we ever discover that we need it. -- Mike <| Post or View Comments |>