"John.Cowan" <jcowan@xxxxxxxxxxxxxxxxx> writes: > Thomas Bushnell BSG scripsit: > >> > Can you live with 2^24? >> >> No. Have you heard of sparse arrays? They need indices too. > > Sparse arrays are not a fundamental R[56]RS type like strings and vectors. > The question is whether these native types need to be Really Really Big. Huh? Sparse arrays are an *implementation* not a datatype.