sequence_complementarity.jl

function dnacompl(nt::Char)
    @assert nt ∈ ('A', 'T', 'C', 'G', 'N', '*')
    if nt == 'A'
        return 'T'
    elseif nt == 'T'
        return 'A'
    elseif nt == 'G'
        return 'C'
    elseif nt == 'C'
        return 'G'
    elseif nt == 'N' || nt == '*'
        return nt
    end
end;

function dnacompl(seq::AbstractString)
    return join(dnacompl.(collect(seq)))
end;