> One of the reasons I like languages with more advanced types systems such as Haskell's or Scala's is because test suites in other languages to achieve the sam

> One of the reasons I like languages with more advanced types systems such as Haskell's or Scala's is because test suites in other languages to achieve the same code coverage take much longer to run. Do you mean Haskell has better runtime performance than dynamic languages, test for test, or that programs in dynamic languages need more tests (say, tests of function return types), or both? In practice programs are written by programmers, not generated randomly, so it is not necessary to test "all the things that can go wrong" but only the things that programmers actually do wrong in practice.