Haskell is very strict in what the compiler allows you to do where. It's a really great alternative to just requiring developer discipline. It means that you ca

Haskell is very strict in what the compiler allows you to do where. It's a really great alternative to just requiring developer discipline. It means that you can do some things (like refactoring) with much greater confidence because the compiler rules out some big classes of bugs. Same with using other people's libraries. You can only use them certain ways and they are explicit. A side effect of being so strict (in the sense of picky) about what is allowed where is that it needs some really powerful abstractions to keep that from slowing you down. Its type system shines here. Often, these abstractions have a nice syntax in haskell and it makes for some really clean code, relative to a direct translation in other languages.