From ea2664a44545cd5f245bf8bc96ae6554eb51173c Mon Sep 17 00:00:00 2001
From: Erik Post <erik@shinsetsu.nl>
Date: Thu, 1 Oct 2020 19:41:58 +0200
Subject: [PATCH] Eliminate Context2DEff in favour of Effect Context2D.

---
 src/Canvas.purs            | 22 ++++++++++------------
 src/CanvasInterpreter.purs | 15 ++++++++-------
 src/Main.purs              |  6 +++---
 3 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/src/Canvas.purs b/src/Canvas.purs
index 50afe86..496a17a 100644
--- a/src/Canvas.purs
+++ b/src/Canvas.purs
@@ -7,31 +7,29 @@ import Language (Distance (), Angle (), Color (..))
 
 foreign import data Context2D :: Type
 
-type Context2DEff = Effect Context2D
-
 type CanvasStyleString = String
 
-foreign import get2DContext :: String -> Context2DEff
+foreign import get2DContext :: String -> Effect Context2D
 
-foreign import initContext :: CanvasStyleString -> Context2D -> Context2DEff
+foreign import initContext :: CanvasStyleString -> Context2D -> Effect Context2D
 
-foreign import beginStroke :: Context2D -> Context2DEff
+foreign import beginStroke :: Context2D -> Effect Context2D
 
-foreign import endStroke :: Context2D -> Context2DEff
+foreign import endStroke :: Context2D -> Effect Context2D
 
-foreign import lineTo :: Distance -> Distance -> Context2D -> Context2DEff
+foreign import lineTo :: Distance -> Distance -> Context2D -> Effect Context2D
 
-drawArc :: Distance -> Distance -> Distance -> Angle -> Angle -> Context2D -> Context2DEff
+drawArc :: Distance -> Distance -> Distance -> Angle -> Angle -> Context2D -> Effect Context2D
 drawArc = drawFilledArc' "transparent"
 
-drawFilledArc :: Maybe Color -> Distance -> Distance -> Distance -> Angle -> Angle -> Context2D -> Context2DEff
+drawFilledArc :: Maybe Color -> Distance -> Distance -> Distance -> Angle -> Angle -> Context2D -> Effect Context2D
 drawFilledArc col = drawFilledArc' $ maybe "" colorToCanvasStyle col
 
-foreign import drawFilledArc' :: CanvasStyleString -> Distance -> Distance -> Distance -> Angle -> Angle -> Context2D -> Context2DEff
+foreign import drawFilledArc' :: CanvasStyleString -> Distance -> Distance -> Distance -> Angle -> Angle -> Context2D -> Effect Context2D
 
-foreign import moveTo :: Distance -> Distance -> Context2D -> Context2DEff
+foreign import moveTo :: Distance -> Distance -> Context2D -> Effect Context2D
 
-foreign import setStrokeStyle :: String -> Context2D -> Context2DEff
+foreign import setStrokeStyle :: String -> Context2D -> Effect Context2D
 
 colorToCanvasStyle :: Color -> String
 colorToCanvasStyle col = case col of
diff --git a/src/CanvasInterpreter.purs b/src/CanvasInterpreter.purs
index 5a3c611..5559e48 100644
--- a/src/CanvasInterpreter.purs
+++ b/src/CanvasInterpreter.purs
@@ -8,6 +8,7 @@ import Control.Monad.Free (runFreeM)
 import Control.Monad.State (State, evalState, get, modify_, put)
 import Data.Tuple
 import Data.Foldable
+import Effect (Effect)
 import Math (sin, cos, pi, (%))
 
 -- | x, y, rotation, isPenDown
@@ -17,11 +18,11 @@ instance turtleShow :: Show Turtle where
   show (Turtle x y angle isPenDown) = "(Turtle " <> show x <> " " <> show y <> " " <> show angle <> " " <> show isPenDown <> ")"
 
 
-interpretTurtleProg :: forall a. TurtleProg a -> Context2D -> Context2DEff
+interpretTurtleProg :: forall a. TurtleProg a -> Context2D -> Effect Context2D
 interpretTurtleProg turtleProg ctx = foldl (>>=) (pure ctx) (interpretTurtleProg' turtleProg)
 
 
-interpretTurtleProg' :: forall a. TurtleProg a -> Array (Context2D -> Context2DEff)
+interpretTurtleProg' :: forall a. TurtleProg a -> Array (Context2D -> Effect Context2D)
 interpretTurtleProg' turtleProg =
 
   evalState turtleProgState (Turtle 0.0 0.0 0.0 true)
@@ -31,13 +32,13 @@ interpretTurtleProg' turtleProg =
 
 
 -- | A natural transformation from `TurtleProg` to `State Turtle`.
-interpretTurtleProg'' :: TurtleProg   (Array (Context2D -> Context2DEff))
-                      -> State Turtle (Array (Context2D -> Context2DEff))
+interpretTurtleProg'' :: TurtleProg   (Array (Context2D -> Effect Context2D))
+                      -> State Turtle (Array (Context2D -> Effect Context2D))
 interpretTurtleProg'' = runFreeM interpret
 
   -- pick off the outermost TurtleCmd from the TurtleProg and process it
-  where interpret :: TurtleCmd    (TurtleProg (Array (Context2D -> Context2DEff)))
-                  -> State Turtle (TurtleProg (Array (Context2D -> Context2DEff)))
+  where interpret :: TurtleCmd    (TurtleProg (Array (Context2D -> Effect Context2D)))
+                  -> State Turtle (TurtleProg (Array (Context2D -> Effect Context2D)))
     
         interpret (Forward r rest) = do
           Turtle x y angle p <- get
@@ -81,7 +82,7 @@ adjacent r angle = r * cos angle
 opposite r angle = r * sin angle
 rad angleDegrees = (2.0 * pi * (angleDegrees % 360.0)) / 360.0
 
-renderTurtleProgOnCanvas :: String -> TurtleProg Unit -> Context2DEff
+renderTurtleProgOnCanvas :: String -> TurtleProg Unit -> Effect Context2D
 renderTurtleProgOnCanvas canvasId prog =
   get2DContext canvasId >>=
   initContext (colorToCanvasStyle Purple) >>=
diff --git a/src/Main.purs b/src/Main.purs
index bb0ca49..4642cab 100644
--- a/src/Main.purs
+++ b/src/Main.purs
@@ -2,12 +2,12 @@ module Main where
 
 import Prelude
 import Language
+import Canvas (Context2D)
 import CanvasInterpreter
-import Canvas (Context2DEff (..))
 import Control.Monad
+import Effect (Effect)
 
-
-main :: Context2DEff
+main :: Effect Context2D
 main = renderTurtleProgOnCanvas "turtleCanvas" $ do
   star
   penUp