Ketil Malde
You've lost me at least.
...but perhaps I can find my way back on my own? Today, you can choose between Array, with lazy elements, or UArray, with strict elements. Lazy arrays have the elements defined in advance, strict ones have them calculated in advance - with the tremendous advantage of being able to eliminate the pointer for each element. Otherwise a pointer is needed to point to a potentially unevaluated thunk. Perhaps there is a middle ground here, if you add the restriction that the elements are generated in order? This way, you only need one pointer to an unevaluated thunk (which will yield all remaining elements as needed), and an unboxed array can contain the calculated values. This would be very nice for e.g. sequence alignment, where the alignment matrix is self-referencing, but the pointers represent a very real cost to an already expensive (resource-intesive) solution. -k -- If I haven't seen further, it is by standing in the footprints of giants