> On Jan 3, 2020, at 1:51 PM, John Cowan <xxxxxx@ccil.org> wrote:
>
> I'm writing a non-mathematician's guide to SRFI 122 (partly for my own benefit), and I'm not clear how immutable arrays are supposed to work.  Is it an error if the getter function is not pure and functional (i.e. depends on something other than the indices passed)?

You are correct, “immutable” arrays are ones that don’t have a mutator in the interface (i.e., it is an error to call (array-setter A)).  There is no guarantee that (array-getter A) is a “pure” function.

Brad