generalize Item from Text to Textual

1 files changed, 18 insertions, 16 deletions

diff --git a/src/TextViewport/Viewport/Instance.hs b/src/TextViewport/Viewport/Instance.hs
index 1bafcbd..c3ce338 100644
--- a/src/TextViewport/Viewport/Instance.hs
+++ b/src/TextViewport/Viewport/Instance.hs
@@ -1,5 +1,7 @@
 module TextViewport.Viewport.Instance where
 
+import Data.Hashable (Hashable)
+import Data.Sequences (Index, Textual)
 import TextViewport.Buffer.Item
 import TextViewport.Buffer.Buffer (Buffer)
 import TextViewport.Buffer.Buffer qualified as Buffer
@@ -12,64 +14,64 @@ import TextViewport.Viewport.Viewport (Viewport, clampViewport, mkViewport)
 import TextViewport.Viewport.Viewport qualified as Viewport
 
 
-data Instance = Instance
-  { viRender :: RenderState
+data Instance a = Instance
+  { viRender :: RenderState a
   , viView   :: Viewport
   } deriving (Show)
 
-mkInstance :: Int -> Int -> Buffer -> Instance
+mkInstance :: (Hashable a, Textual a, Index a ~ Int) => Int -> Int -> Buffer a -> Instance a
 mkInstance width height buf =
   let rs = mkRenderState width buf
       vp = mkViewport width height rs
   in Instance rs vp
 
-visibleLines :: Instance -> [RenderedLine]
+visibleLines :: Instance a -> [RenderedLine a]
 visibleLines (Instance rs vp) =
   take (Viewport.vpHeight vp) . drop (Viewport.vpOffset vp) . RenderedBuffer.flatten $ RenderState.rsRendered rs
 
-applyToInstance :: (Viewport -> Viewport) -> Instance -> Instance
+applyToInstance :: (Viewport -> Viewport) -> Instance a -> Instance a
 applyToInstance f (Instance rs vp) =
   let vp' = f vp
   in Instance rs (clampViewport rs vp')
 
-applyToInstanceRS :: (RenderState -> Viewport -> Viewport) -> Instance -> Instance
+applyToInstanceRS :: (RenderState a -> Viewport -> Viewport) -> Instance a -> Instance a
 applyToInstanceRS f (Instance rs vp) =
   let vp' = f rs vp
   in Instance rs (clampViewport rs vp')
 
-scrollByI :: Int -> Instance -> Instance
+scrollByI :: Int -> Instance a -> Instance a
 scrollByI delta = applyToInstance (Viewport.scrollBy delta)
 
-scrollUpI :: Int -> Instance -> Instance
+scrollUpI :: Int -> Instance a -> Instance a
 scrollUpI delta = applyToInstance (Viewport.scrollUp delta)
 
-scrollDownI :: Int -> Instance -> Instance
+scrollDownI :: Int -> Instance a -> Instance a
 scrollDownI delta = applyToInstance (Viewport.scrollDown delta)
 
-pageUpI :: Instance -> Instance
+pageUpI :: Instance a -> Instance a
 pageUpI = applyToInstance Viewport.pageUp
 
-pageDownI :: Instance -> Instance
+pageDownI :: Instance a -> Instance a
 pageDownI = applyToInstance Viewport.pageDown
 
-alignTopI :: Instance -> Instance
+alignTopI :: Instance a -> Instance a
 alignTopI = applyToInstance Viewport.alignTop
 
-alignBottomI :: Instance -> Instance
+alignBottomI :: Instance a -> Instance a
 alignBottomI = applyToInstanceRS Viewport.alignBottom
 
-modifyItemI :: Int -> (Item -> Item) -> Instance -> Instance
+modifyItemI :: (Hashable a, Textual a, Index a ~ Int) => Int -> (Item a -> Item a) -> Instance a -> Instance a
 modifyItemI ix f (Instance rs vp) =
   let buf' = Buffer.modifyItem ix f (RenderState.rsBuffer rs)
       rs'  = mkRenderState (RenderState.rsWidth rs) buf'
       vp'  = clampViewport rs' vp
   in Instance rs' vp'
 
-lookupPositionI :: Int -> Int -> Instance -> Maybe (Int, Int)
+lookupPositionI :: Int -> Int -> Instance a -> Maybe (Int, Int)
 lookupPositionI x y (Instance rs vp) =
     lookupPosition x y vp (RenderState.rsRendered rs)
 
---debugVI :: Instance -> IO ()
+--debugVI :: Instance a -> IO ()
 --debugVI (Instance rs vp) = do
 --  putStrLn ("offset = " ++ show (Viewport.vpOffset vp))
 --  putStrLn ("height = " ++ show (Viewport.vpHeight vp))