On Sun, Mar 22, 2009 at 08:10:28PM -0300, Rafael Cunha de Almeida wrote:
Doing it like that I could have all the definitions in one module, but it doesn't solve another important problem: keyboardMouse and display functions have to have as many parameters as there are IORefs.
You may always create a new data type.
Whereas in Haskell I would have something like keyboard var1 _ LeftKey = ... keyboard _ var2 RightKey = ... If I wanted to add a new IORef I'd have to do something like: keyboard var1 _ _ LeftKey = ... keyboard _ var2 _ RightKey = ... keyboard _ _ var3 RightKey = ... So, I had to change all previous definitions.
Initial code:
data Vars = Vars {var1 :: {-# UNPACK #-} !(IORef Type1) ,var2 :: {-# UNPACK #-} !(IORef Type2)}
keyboard v LeftKey = ... (var1 v) ... keyboard v RightKey = ... (var2 v) ...
Modified code:
data Vars = Vars {var1 :: {-# UNPACK #-} !(IORef Type1) ,var2 :: {-# UNPACK #-} !(IORef Type2) ,var3 :: {-# UNPACK #-} !(IORef Type3)}
keyboard v LeftKey = ... (var1 v) ... -- unchanged keyboard v RightKey = ... (var2 v) ... -- unchanged keyboard v OtherKey = ... (var3 v) ...
Note that the UNPACKs aren't really necessary. -- Felipe.