[danwilsonthomas]

> This should be really interesting, considering that Code Review and Automated Tests are far more likely to root out important bugs than a type checker.

Not to bring up the tired argument again, but as far as I know there isn't proof for this. Nor is there proof that types are better at catching bugs than tests or code review. The best we can hope for is anecdata. I've got my fair share that shows types in a good light and I'm sure you've got your fair share that shows tests in a good light.

That being said, global type inference is in my opinion a fundamental game changer here. No longer are you required to put effort into your types up front. It is the only one of those three tools with that property. This makes it trivial to get "100% coverage" with types. That is why people argue for static type coverage.

Additionally, Haskell specifically has a switch to defer type errors to runtime, which means you can compile and test without 100% coverage.