Matthew Roberts
I find that I don't need unit testing frameworks. A few features of Haskell and the associated interpreters (ghci and hugs) combine to make "unit testing as you go" really easy. I just write a few tests for each function I write and then some more module wide tests once the whole module is finished. Sometimes I need a little scaffolding to be able to output complex data types (or type synonyms), but often just deriving Show does the job!
It seems to me that if you're going to take the time to craft some ad-hoc tests in the interpreter, you might as well take an extra few seconds to put them into HUnit tests so you can make sure they still pass later. This gives you more confidence while you are refactoring your code. peace, isaac