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10. DNA-to-RNA transcription

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, 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 trans method:

my %transcription =
    A => 'U', C => 'G', G => 'C', T => 'A';

my $dna = 'ACCATCAGTC';
my $rna = $dna.trans(%transcription);
say $rna; # UGGUAGUCAG

↻ Runs in Rakudo; the in-browser engine (Raku++) doesn’t support this program yet — see the expected output above.

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');

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10. DNA-to-RNA transcription

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