I think you'll have a problem with the argument structure:
sub revdnacomp {
# my $dna = @_;
# the above means $dna gets the number of
# arguments in @_, since it's a scalar context!
my $dna = shift; # or my $dna = shift @_;
# ah, scalar context of scalar gives expected results.
# my ($dna) = @_; # would work, too
my $revcomp = reverse($dna);
$revcomp =~ tr/ACGTacgt/TGCAtgca/;
return $revcomp;
}
but why not allow the complementation over more than one element?
sub revcompl { # operates on all elements passed in
my (@dna) = @_;
foreach my $segment (@dna) {
my $revcomp = reverse($segment);
$revcomp =~ tr/ACGTacgt/TGCAtgca/;
push @done, $revcomp;
}
return @done; # or reverse @done; # what's best semantics?
}
Did I miss anything?