> fast append If you're mutating it, yes. And CL/Scheme do offer that datatype. Linked lists support a functional style building shared structures without hav

> fast append If you're mutating it, yes. And CL/Scheme do offer that datatype. Linked lists support a functional style building shared structures without having to worry about plan interference from the mutations. Clojure can do this with immutable arrays instead of lists, but the implementation is hairier than either linked lists or mutable arrays.