Just curious, has anybody tried to apply Halstead's code metrics [...]
As I understand it, Halstead's metric punishes the re-use of "operands" (= variables). This is what happens if you start your program with a bunch of global definitions (e.g. int i,j,k,l because you might want them as loop indices) that actually should be local. This totally does not apply to Haskell: there is no assignment, you cannot overwrite, so indeed each operand ("variable") serves only one purpose, as it should be. NB: My private set of Haskell metrics: * lines of code (per declaration) (should be <= 5) * number of declarations (per module) (should be <= 5 as well :-) * number of usages of Int, String, List, IO (should be <= 0 :-) :-) Not entirely joking - J.W.