[Haskell-cafe] Re: A free monad theorem?

[Tomasz Zielonka]

On Sun, Sep 03, 2006 at 01:23:13AM +0200, jerzy.karczmarczuk at info.unicaen.fr wrote:
> Tomasz Zielonka: 
> 
> >Programmers define the >>= method for their monads because they want to
> >use it to bind computations. They know how to pass result(s) from
> >one computation in their Monad to another, and they put this algorithm
> >in the implementation of >>=. If they didn't care about passing results
> >from one computation to the next one, they wouldn't be using monads in
> >the first place.
> 
> Shrug.
> If these programmers didn't care about passing results from one computation
> to the next one, they wouldn't use functional programming at all.
> Hm.
> Would it still be "programming"?... 

I myself wanted to write that then they wouldn't be using a general
purpose programming language, but something like HTML, etc.

But then I thought that you may want to have "computations" that can't
pass values between each other. One example is an algebraic datatype for
describing tree-like structures - but you could argue that there is a
bottom-up data flow. Anyway, I haven't thought about it too much...

Best regards
Tomasz