I posted a reply to the same post.

I was thinking a really lazy way to do this would be to make up a locale with just the ACGNT letters and then have to magic autoincrement operator just do the Right Thing.

use POSIX qw(locale_h);
setlocale(LC_ALL, "DNA");
use locale;

my @twos=(AA..TT);
#with all above working @twos would be AA AC AG AN AT CA CC CG etc.
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So my question for the folks in the know is does the autoincrementer use locale?
Has anyone defined a DNA locale?