[Haskell-cafe] Monad Description For Imperative Programmer

[david48]

On 8/1/07, Andrew Wagner <wagner.andrew at gmail.com> wrote:
> This seems wrong to me. A monad is, first and foremost, a type
> constructor class. I'm not sure how you can really compare that to a
> loop. But perhaps the easiest way to test your definition would be to
> ask this: How is, for example, the Maybe monad like a loop, in your
> definition?

As a beginner haskeller coming from an imperative experience, I think
I understood what he meant.

say you have this code :

   putStrLn "1" >> putStrLn "2" >> putStrLn "3"

you can imagine each of the calls to putStrLn gets implicitly passed a
variable (here, the world ) and they happen in succession so it's
"like a loop".

Except that a loop... loops so the comparison is far fetched.