[Haskell-cafe] Problem with own written monad

[Miguel Mitrofanov]

> 	data Stack a = Stack { run :: [a] -> (a, [a]) }

[...skipped...]

> But, I have simply no clue how to fix that. :-(
> Can anybody give my a hint?

Yes. It's simply impossible. The Stack data type can't be turned into  
a monad.

May be you can explain what do you want to do with this "monad"? What  
kind of code would you write if it would be such monad?