From dc004b45f8b499a4c35b08f8e18f641354f9b9d1 Mon Sep 17 00:00:00 2001
From: Camil Staps
Date: Tue, 22 Oct 2019 14:52:47 +0200
Subject: Add custom GtkM state monad with a bind that does not grow the stack

---
 src/Gtk/State.dcl | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

(limited to 'src/Gtk/State.dcl')

diff --git a/src/Gtk/State.dcl b/src/Gtk/State.dcl
index e97f3d3..2a5396c 100644
--- a/src/Gtk/State.dcl
+++ b/src/Gtk/State.dcl
@@ -2,11 +2,9 @@ definition module Gtk.State
 
 from StdMaybe import :: Maybe
 
-from Control.Applicative import class pure
-from Control.Monad.State import :: State, :: StateT,
-	instance pure (StateT m s)
-from Control.Monad.Identity import :: Identity,
-	instance pure Identity
+from Control.Applicative import class pure, class <*>, class Applicative
+from Control.Monad import class Monad
+from Data.Functor import class Functor
 from Data.Map import :: Map
 
 from Gtk.Signal import :: GSignalHandlerInternal
@@ -18,12 +16,22 @@ from Gtk.Signal import :: GSignalHandlerInternal
 	, signal_counter  :: !Int
 	}
 
-:: GtkM a :== State GtkState a
+:: GtkM a =: GtkM (GtkState -> (a, GtkState))
+
+instance Functor GtkM
+instance pure GtkM
+instance <*> GtkM
+instance Monad GtkM
+where
+    (>>|) infixl 1 :: (GtkM a) (GtkM b) -> GtkM b
 
 newGtkState :: GtkState
 
 runGtk :: !(GtkM a) !*World -> (!a, !*World)
 
+getState :: GtkM GtkState
+modState :: !(GtkState -> GtkState) -> GtkM GtkState
+
 toState :: !(A.a: a -> a) -> GtkM ()
 toStateR :: !(A.a: a -> (r,a)) -> GtkM r
 
-- 
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