As there are non-Turing complete languages out there, and given I didn't study Comp Sci at university, could someone explain something that a Turing-incomplete language (like Coq) cannot do?
Or is the completeness/incompleteness of no real practical interest (i.e. does it not make much difference in practice)?
EDIT - I'm looking for an answer along the lines of you cannot build a hash table in a non-Turing complete language due to X, or something like that!