Bioinformatics/base count

It's the Letter frequency task all over again, just simpler and dressed up in different clothes.

The specs for what "pretty print" means are sadly lacking. Ah well, just makes it easily defensible if I do anything at all.

my $dna = join '', lines q:to/END/;
    CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG
    CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG
    AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT
    GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT
    CGATTCTGCTTATAACACTATGTTCTTATGAAATGGATGTTCTGAGTTGG
    TCAGTCCCAATGTGCGGGGTTTCTTTTAGTACGTCGGGAGTGGTATTATA
    TTTAATTTTTCTATATAGCGATCTGTATTTAAGCAATTCATTTAGGTTAT
    CGCCGCGATGCTCGGTTCGGACCGCCAAGCATCTGGCTCCACTGCTAGTG
    TCCTAAATTTGAATGGCAAACACAAATAAGATTTAGCAATTCGTGTAGAC
    GACCGGGGACTTGCATGATGGGAGCAGCTTTGTTAAACTACGAACGTAAT
    END


put pretty($dna, 80);
put "\nTotal bases: ", +my $bases = $dna.comb.Bag;
put $bases.sort(~*.key).join: "\n";

sub pretty ($string, $wrap = 50) {
    $string.comb($wrap).map( { sprintf "%8d: %s", $++ * $wrap, $_ } ).join: "\n"
}

Output:

       0: CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATGCTCGTGCTTTCCAATTATGTAAGCGTTCCG
      80: AGACGGGGTGGTCGATTCTGAGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGATGGGACGTTTC
     160: GTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTTCGATTCTGCTTATAACACTATGTTCTTATGAAATGGATGT
     240: TCTGAGTTGGTCAGTCCCAATGTGCGGGGTTTCTTTTAGTACGTCGGGAGTGGTATTATATTTAATTTTTCTATATAGCG
     320: ATCTGTATTTAAGCAATTCATTTAGGTTATCGCCGCGATGCTCGGTTCGGACCGCCAAGCATCTGGCTCCACTGCTAGTG
     400: TCCTAAATTTGAATGGCAAACACAAATAAGATTTAGCAATTCGTGTAGACGACCGGGGACTTGCATGATGGGAGCAGCTT
     480: TGTTAAACTACGAACGTAAT

Total bases: 500
A       129
C       97
G       119
T       155