flip EST orientation

gistfile1.pl

   my $cDNA_span = shift;
   my $chrom = shift;
   my %est_orient;
   $wormbase->FetchData("estorientation",\%est_orient) unless (5 < scalar keys %est_orient);
   foreach my $EST ( keys %est_orient ) {
     if ( exists $$cDNA_span{$EST} && defined $$cDNA_span{$EST}->[2]) {
   my $GFF_strand = $$cDNA_span{$EST}->[2];
   my $read_dir = $est_orient{$EST};
     CASE:{
     ($GFF_strand eq "+" and $read_dir eq "5") && do {
       $$cDNA_span{$EST}->[2] = "+";
       last CASE;
     };
     ($GFF_strand eq "+" and $read_dir eq "3") && do {
       $$cDNA_span{$EST}->[2] = "-";
       last CASE;
     };
     ($GFF_strand eq "-" and $read_dir eq "5") && do {
       $$cDNA_span{$EST}->[2] = "-";
       last CASE;
     };
     ($GFF_strand eq "-" and $read_dir eq "3") && do {
       $$cDNA_span{$EST}->[2] = "+";
       last CASE;
     };
   }
     }
   }