sub sortsub { $a cmp $b || other_function( $a, $b ) || ... } #### sub sortsub { string_compare( $a, $b ) || other_function( $a, $b ) || ... } #### sub sortsub { my @subs = @_; foreach my $sub ( @subs ) { my $result = $sub->($a, $b); return $result if $result; } } #### sub make_sort_sub { my @subs = @_; return sub { foreach my $sub ( @subs ) { my $result = $sub->($a, $b); return $result if $result; } }; } #### my $sort_sub = make_sort_sub( @sub_references ); my @sorted = sort { $sort_sub->() } @stuff; #### #!/usr/bin/perl # pre-defined common sort subroutines my %Subs = ( numeric_descending => sub { $b <=> $a }, numeric_ascending => sub { $a <=> $b }, string_descending => sub { $b cmp $a }, string_ascending => sub { $b cmp $a }, case_insensitive => sub { "\L$a" cmp "\L$b" }, ); sub make_sort_sub { my @subs = @_; return sub { foreach my $sub ( @subs ) { my $result = $sub->($a, $b); return $result if $result; } }; } # numbers { my @use_these_subs = map { $Subs{$_} } qw(numeric_descending); my $sort_sub = make_sort_sub( @use_these_subs ); my @sorted = sort { $sort_sub->() } qw( 1 10 11 100 2 12 21 3 31 300 4 5 6 66 7 71 ); print "@sorted\n"; } # strings { my @use_these_subs = map { $Subs{$_} } qw(case_insensitive string_ascending); my $sort_sub = make_sort_sub( @use_these_subs ); my @sorted = sort { $sort_sub->() } qw( Fred fred FReD Barney barney Betty BETTY ); print "@sorted\n"; } # strings by length with user defined subroutine { my @use_these_subs = ( sub { length $a <=> length $b } ); push @use_these_subs, map { $Subs{$_} } qw(string_ascending); my $sort_sub = make_sort_sub( @use_these_subs ); my @sorted = sort { $sort_sub->() } qw( Fred fred FReD Barney barney Betty BETTY ); print "@sorted\n"; }