updating labelled fields

[Iavor S. Diatchki]

Hello,

I am not sure if this is what is needed, but you can do the following in 
Hugs (with extensions):

data T = T
    { x :: Int
    , y :: Char
    }

f s@T {x} = s { x = x + 1 }

This increments the first field in the record, and leavs the second one 
unchanged.
It makes use of punning, a very useful feature I think, which unfortunately
was removed from Haskell, I am not sure why.  It is still supported in 
Hugs however.

bye
Iavor