1arrayfields allow keyword access to array instances. 2arrayfields works by adding only a few methods to arrays, 3namely #fields= and fields, but the #fields= method is 4hooked to extend an array on a per object basis.In 5otherwords __only__ those arrays whose fields are set 6will have auto-magical keyword access bestowed on 7them - all other arrays remain unaffected.arrays with 8keyword access require much less memory when compared 9to hashes/objects and yet still provide fast lookup and 10preserve data order. 11