Note that as of Elm version 0.19, the memoizing elm-lang/lazy package
was dropped. This lazy list implementation does not memoize. This type of lazy
list is often called a sequence, and it will be less lazy than a true lazy list
but is a reasonable compromise without memoizing support from the runtime.
Many functions have been made tail recursive where they were not in the original 1.0.0 release.
product2 and product3 have been made tail recursive.
