except that they had to write unit tests - whereas the compiler/type system automatically checked the type safety of the code this guy wrote.

(Not that writing unit tests for haskell code is a bad idea - QuickCheck is WAY more powerful than junits, for example)

QuickCheck and JUnit have different purposes. QuickCheck is not a unit testing framework.

> QuickCheck and JUnit have different purposes. QuickCheck is not a unit testing framework.

Indeed. What I meant was that basically:

    P(HaskellCodeCorrect|Compile+QC+UnitTest) =~= P(OtherCodeCorrect|Compile+UnitTest)

while the distribution of effort between compilation (if any) and unit tests in other languages are quite different than in Haskell, i.e. skewed towards tests in the former and getting code to compile in the latter case.