-Idle ADR question: What's the tradeoff here between flattening these
-datatypes into @MutableArray ix ix (MutableArray# s elt)@ and using
-it as is? As I see it, the former uses slightly less heap and
-provides faster access to the individual parts of the bounds while the
-code used has the benefit of providing a ready-made @(lo, hi)@ pair as
-required by many array-related functions. Which wins? Is the
-difference significant (probably not).
-
-Idle AJG answer: When I looked at the outputted code (though it was 2
-years ago) it seems like you often needed the tuple, and we build
-it frequently. Now we've got the overloading specialiser things
-might be different, though.
-