Lazily evaluated lists in Python
A lazylist.List accepts a single iterable as its only constructor argument.
The intention is for this to be a generator. The lazylist.List will
behave as a normal list does, but will only evaluate the iterable as it needs
to. If there is a request for index [5], then elements 0 - 5 will be
evaluated if they have not been yet. Certain operations like len and
negative indexing will force the list to be evaluated. This decision was made
to make the lazylist outwardly appear as much like a normal list as possible.