[Haskell-cafe] What is your favourite Haskell "aha" moment?

[Stefan Monnier]

> For me there were two important "aha" moments. Right at the beginning I was
> drawn in by using ADTs and pattern-matching on them. It's so simple and
> plain and now it's the first thing I miss in any other language I have to
> work with. I feel like this would make a short, compelling example for
> programmers coming from any other background.

Indeed, the one thing I really miss when hacking on Elisp is the great
help I get from my Haskell/ML typecheckers when I modify one of my
datatypes, showing me exhaustively (or close enough) all the places
where changes are needed.


        Stefan