Python-based monads essay (Re: Assignment versus binding)

[Rustom Mody]

On Tuesday, October 11, 2016 at 9:53:25 PM UTC+5:30, Anuradha Laxminarayan wrote:
> On Sunday, 9 October 2016 13:18:32 UTC+5:30, Gregory Ewing  wrote:
> > Here's the first part of the essay I said I'd write about
> > monads:
> > 
> > http://www.cosc.canterbury.ac.nz/greg.ewing/essays/monads/DemystifyingMonads.html
> > 
> > Hope it's useful,
> > Greg
> 
> Thanks, that made a very interesting read.

Yeah agreed!

Just got it running in ghc.
Some small modifications needed:

import Data.Set

add x f s = f (insert x s)
listify f s = f (toList s) s
seqq f g x = f (\s1 -> g x s1)

dedup (x:t) = seqq (add x) (dedup t)
dedup [] = listify

run_smf f a = f a (\r s -> r) empty

> seq f g h = f (\s1 -> g h s1)

> better be written as

> seq f g x = f (\s1 -> g x s1)

> because naming conventions imply that h is function.

I think it would be good to make state and adhere to a name-convention eg
c for continuation
f,g for general function
s for state
etc

Otherwise excellent work! V useful