> you simply need to put a "!" before the term to evaluate in order to get eagerness That's wrong. With the bang pattern, evaluation only goes up to WHNF, not

> you simply need to put a "!" before the term to evaluate in order to get eagerness That's wrong. With the bang pattern, evaluation only goes up to WHNF, not the whole way — it's just a syntax sugar around "seq" which has been around since always. If you need to fully evaluate the term, look at the deepseq package: it's implementation is non-trivial.