Random-access lists are often used as functional vectors, hence
vector-like constructors may be useful.  In particular, a random-access
version of `make-list' can construct lists represented in a very space
efficient manner, O(log n), thanks to sharing.  I propose the following
be added to SRFI 101.  I'm on the fence about whether the unary
`make-list' is useful, though.  Comments welcome.

David

(make-list k)            procedure
(make-list k fill)       procedure

Returns a newly allocated list of k elements. If a second argument is
given, then each element is initialized to fill. Otherwise the initial
contents of each element is unspecified.