Help for this page
DB<8> x ["a",=>"b"] 0 ARRAY(0x54e32f0) ... 0 ARRAY(0x54e2cd8) 0 'a' 1 'b'
DB<12> x map {lc,$_} "A".."C" 0 'a' ... 3 'B' 4 'c' 5 'C'