[Haskell-cafe] Is there any way to parametrize a value update using record syntax?

6 Sep 2011

      Hi all,

i have a record with a lot of items used in a state monad.

data BigData = BigData {
                   data1 :: X
                 , data2 :: X
		-- and so on
                }

type MonadicEnv a = State BigData a

I updates the fields in the computation with such functions:

updateData1 :: X -> MonadicEnv()
updateData1 d = do; env <- get; put env {data1 = d} 

updateData2 :: X -> MonadicEnv()
updateData2 d = do; env <- get; put env {data2 = d} 

But it's ugly. Always the same, only the record selector has another
name.
Is it possible to generalize it?

Thanks,
Árpád

[Haskell-cafe] Is there any way to parametrize a value update using record syntax?

Poprádi Árpád