Reddit discussion considered productive

Wow! I didn’t expect the spanish inquisition getting on the front-page of programming.reddit.com (I didn’t even submit my post to the site) and sparkling such a lively discussion there. I would just reply there, but I somehow feel it’s better to leave a more “permanent” record — even if for my own future reference — of my thoughts on the issues raised.

Vintermann’s interpretation of my point was this:

The issue for me is that from the syntax, you could believe

greet = do {
putStr (”You’re “++ getLine ++”years old! \n”);
putStr (”Congratulations! \n”);
}

was valid haskell, which it isn’t

This is specially true since <- as destructive update/assignment is used in many pseudocode languages in introductory books — particularly Knuth’s TAOCP, as well as some languages (like The Other Language I Use, GNU R).

Ricercar adds

(…) [M]onads are not limited to one interpretation, whereas “do notation” is strongly tied to the imperative interpretation.
This is much like “Lawyer Language” that is confusing precisely because it looks somewhat like natural language, when it really isn’t.

Well, yes, I couldn’t agree more. Maybe I’m unconsciously selecting the favorable comments — the one that further illustrate my point. But let’s examine pjdelport’s reply:

Breadcrumb trails: