I did originally have them as lists of lists, but flattening out into the "array of key/value pairs" idea sped up my constructor by about 10%, which was pretty significant.

xoxo,
Andy

%_=split/;/,".;;n;u;e;ot;t;her;c; ".   #   Andy Lester
'Perl ;@; a;a;j;m;er;y;t;p;n;d;s;o;'.  #   http://petdance.com
"hack";print map delete$_{$_},split//,q<   andy@petdance.com   >