use strict;
use warnings;

my %Functions =
  (
    'A' => { func => \&Sort1 },
    'B' => { func => \&Sort2 },
    'C' => { func => \&Sort3 },
    'D' => { func => \&Sort4 },
    'E' => { func => \&Sort5 },
  );


sub GeneralizedFunction
  {
     my ( $flag ) = @_;

     # some processing

     if ( defined $Functions{ $flag } ) {
        $Functions{ $flag }{func}->(); # generalized sort
     }

     # other processing
  }