[Haskell-cafe] A Question of Restriction

[Brian Troutwine]

Hello Wouter.

I've had a go at the paper linked and perused other references found
with Google. Unfortunately, such sophisticated use of the type system
is pretty far out of my normal problem domain and I can't see how to
apply the techniques presented to my motivating example. Would you be
so kind as to elaborate?

Thank you,
Brian

On Mon, Jul 27, 2009 at 2:37 AM, Wouter Swierstra<wss at cs.nott.ac.uk> wrote:
> Hi Brian,
>
> If I understand you correctly, you've run into the "Expression Problem".
> Phil Wadler posed the problem in a widely-cited e-mail, formulating it much
> more clearly than I ever could:
>
>  http://homepages.inf.ed.ac.uk/wadler/papers/expression/expression.txt
>
> There are lots of ways to tackle this problem in Haskell - just google
> "Expression Problem Haskell". My (completely biased) personal favourite is:
>
>  http://www.cse.chalmers.se/~wouter/Publications/DataTypesALaCarte.pdf
>
> Hope this helps,
>
>  Wouter
>
>