I myself heard "programmable semicolon" sometime after monads had clicked for me, but I still appreciate it. To answer Tom's question, what these short single sentences do is explain the *purpose* of monads, which is really quite obscure at first. Listing sequential actions one after the other is so intuitive you see it everywhere. Take baking recipes as one example. Or assembly code. Or poems. Procedural programming languages let you use the same intuition for sequencing actions you've been using since you were carving hieroglyphics into obelisks. When a Haskeller says, "Monads are great! They let you chain effectful actions together!" it can take a very long time to understand they actually mean exactly what they're saying — the usual intuition is that sequencing actions can't possibly be a real problem, so you go round and round in circles trying to understand what "effectful" means, what "action" means, and how these oh-so-important "laws" have anything to do with it. A programmable semicolon cuts right to the truth: yes, really, functional programming had to work hard to solve *that* problem. I can understand why that viewpoint might be long-forgotten by those who were involved in the effort to solve it. :) And I appreciate that it was solved in such a general way that it can be applied to so many seemingly unrelated things! That's the beauty of mathematics! On Fri, 17 Sep 2021, 20.11 Tom Ellis, < tom-lists-haskell-cafe-2017@jaguarpaw.co.uk> wrote:
On Fri, Sep 17, 2021 at 05:02:09PM +0000, Richard Eisenberg wrote:
On Sep 17, 2021, at 3:50 AM, Tom Ellis < tom-lists-haskell-cafe-2017@jaguarpaw.co.uk> wrote:
On Fri, Sep 17, 2021 at 01:43:01PM +0900, Michael Turner wrote:
I finally got (most of?) what monads really mean for practical programming when none other than Simon Peyton-Jones said F# called a very similar construct "workflow," a word he likes.
Was it literally just a single sentence introducing a new word for a concept that made you "get it"? Could you elaborate? This is really quite remarkable.
For me, coming from a mostly Java background (but with a healthy dollop of functional programming thrown in the mix -- but no Haskell), the phrase that unlocked monads was "programmable semicolon".
I'm curious what "unlock" means here. Do you mean you could understand the definition of the monad class after coming across "programmable semicolon" but not before? Or do you mean you understood the *purpose* of monads, but not necessarily how one would go about implementing them? Or something else? _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.