Quoth Hans Nowak <[EMAIL PROTECTED]>:
| Paul Rubin wrote:
|
|> You should write unit tests either way, but in Python you're relying
|> on the tests to find stuff that the compiler finds for you with Java.
|
| As I wrote on my weblog a while ago, I suspect that this effect is | largely psychological. You jump through hoops, declaring types all over | the place, checking exceptions, working around the language's | limitations, etc. So when your code compiles, it *feels* safer. Like | you're at least part of the way towards ensuring correctness. All that | work must be good for *something*, right? Never mind that when writing | unit tests for a dynamic language, you don't check for these things at | all. How often do you explicitly check types in Python unit tests? | IMHO, when using a dynamic language, you don't need most of the checks | that Java, C# and their ilk force upon you.
I have been fooling around with strongly, statically typed languages for a couple of years, in my spare time - Objective CAML, Haskell, O'Haskell. This is a little different experience than what you two are talking about - I don't think Java, C# and their ilk are quite as rigorous, nor do they use type inference - but as much as it would probably gag an FP enthusiast to say this, the basic idea is the same.
I can only believe that if you think the benefit of static typing is psychological, either something is very different between the way you and I write programs, or you're not doing it right.
I do think it makes more sense in functional languages like the ones you mention... that's one of the reasons I am trying to learn OCaml. I don't think the type systems in OCaml, Haskell etc can quite be compared to what's used in Java, C#, C++ or Delphi. So far, I am getting the impression that the type system in OCaml is actually there to help you, rather than something that gets in your way.
I concur that in my OCaml experiments so far, errors pointed out by the compiler made a lot more sense, because they pointed to actual problems, rather than being a case of "you didn't declare this method as public static final".
Of course, it helps that, like Python, said languages (OCaml, Haskell) are higher-level than Java/C#/etc, so you can express things concisely and clearly. That might be one of the reasons why static, strong typing in VHLLs has a much higher "return on investment" than it has in lower-level languages, where you have to write acres of code just to get something done (availability of libraries notwithstanding).
-- Hans Nowak http://zephyrfalcon.org/
-- http://mail.python.org/mailman/listinfo/python-list
