PropLang
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A design for a GUI library which is more like Haskell and less like C. To be written over Gtk2Hs.
Link: http://www.cse.unsw.edu.au/~chak/haskell/ports/
Thoughts by
Neil Mitchell, Duncan Coutts
The Var concept
This is the low level stuff, on which the library will be built
data Var a = ... data Notify
get :: Var a -> IO a set :: Var a -> a -> IO () addNotify :: Var a -> (a -> IO ()) -> IO Notify remNotify :: Notify -> IO ()
newVar :: a -> IO (Var a)
Object layering
textBox-text -< "test"
filename <- newVar Nothing
addNotify filename hatCover
lbl-text =< with filename $ \x ->
case x of
Nothing -> "Select a file"
Just x -> "Loaded: " ++ x
where
(-) :: GtkObject -> GtkProp -> Var a -- ignoring lots of details here (-<) :: Var a -> a -> IO () (=<) :: Var a -> Action a -> IO ()
with :: Var a -> (a -> b) -> Action b