Convert the given DNA sequence to a compliment RNA.
We’ll not dig deep into the biology aspect of the problem. For us, it is important that the DNA is a string containing the four letters A, C, G, and T, and the RNA is a string of A, C, G, and U. The transformation from DNA to RNA happens according to the following table:
| DNA | A | C | G | T |
| RNA | U | G | C | A |
In the Str class in Perl 6, the trans method is defined; it takes pairs ‘old character—new character’. So, to translate from DNA to RNA, let’s write the above table as a hash and use it with the transmethod:
my %transcription =
A => 'U', C => 'G', G => 'C', T => 'A';
my $dna = 'ACCATCAGTC';
my $rna = $dna.trans(%transcription);
say $rna; # UGGUAGUCAG
The trans method accepts a few attributes that alternate its behaviour. For example, the :squash attribute removes the duplicated characters. This probably does not make sense in biology, but works for us an exercise:
say $dna.trans(%transcription, :squash); # UGUAGUCAG
It is also possible to replace the sequences of more than one character. For example:
say $dna.trans('ACCA' => 'UGGU', 'TCA' => 'AGU',
'GTC' => 'CAG');