[chc]

The actual post linked here is basically an intro and is kind of "meh" by itself, but the series of posts it introduces is quite good and answers a lot of the questions people have about how you do a seemingly "imperative-style" application in a purely functional language.

[eru]

Yes. I also remember there being a previous discussion about those posts on HN. Does anybody care to dig it out?

[chc]

I checked HNSearch, but I couldn't find one with more than a tiny handful of comments (I think with this comment we're already halfway to matching the most active one).

[silentbicycle]

And don't limit yourself to discussions from just this particular post; many of his other posts have good threads here.