From 230e538e41360f2018db9a8b5274402d0b3200b6 Mon Sep 17 00:00:00 2001
From: tv <tv@krebsco.de>
Date: Mon, 9 Mar 2026 02:25:18 +0100
Subject: generalize Item from Text to Textual

---
 src/TextViewport/Render/RenderState.hs | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

(limited to 'src/TextViewport/Render/RenderState.hs')

diff --git a/src/TextViewport/Render/RenderState.hs b/src/TextViewport/Render/RenderState.hs
index 26e92e1..8c0cdef 100644
--- a/src/TextViewport/Render/RenderState.hs
+++ b/src/TextViewport/Render/RenderState.hs
@@ -1,24 +1,26 @@
 module TextViewport.Render.RenderState where
 
+import Data.Hashable (Hashable)
 import Data.Sequence (Seq)
 import Data.Sequence qualified as Seq
-import TextViewport.Buffer.Item
+import Data.Sequences (Index, Textual)
 import TextViewport.Buffer.Buffer (Buffer(Buffer))
 import TextViewport.Buffer.Buffer qualified as Buffer
+import TextViewport.Buffer.Item
 import TextViewport.Render.RenderBuffer (renderBuffer)
 import TextViewport.Render.RenderCache (RenderCache(..), emptyRenderCacheFor, resizeCache)
 import TextViewport.Render.RenderedBuffer (RenderedBuffer(RenderedBuffer))
 import TextViewport.Render.RenderedBuffer qualified as RenderedBuffer
 
-data RenderState = RenderState
-  { rsBuffer    :: Buffer             -- original items
-  , rsCache     :: RenderCache        -- per-item cached renders
-  , rsRendered  :: RenderedBuffer     -- fully segmented + hyphenated lines
+data RenderState a = RenderState
+  { rsBuffer    :: Buffer a           -- original items
+  , rsCache     :: RenderCache a      -- per-item cached renders
+  , rsRendered  :: RenderedBuffer a   -- fully segmented + hyphenated lines
   , rsWidth     :: Int                -- segmenting width
   , rsLineCount :: Int                
   } deriving (Eq, Show)
 
-mkRenderState :: Int -> Buffer -> RenderState
+mkRenderState :: (Hashable a, Textual a, Index a ~ Int) => Int -> Buffer a -> RenderState a
 mkRenderState width buf =
   let (cache1, rendered) = renderBuffer width buf (emptyRenderCacheFor buf)
   in RenderState
@@ -30,7 +32,7 @@ mkRenderState width buf =
        }
 
 -- RenderState has to be rebuilt whenever the buffer or the width changes.
-updateRenderState :: Int -> Buffer -> RenderState -> RenderState
+updateRenderState :: (Hashable a, Textual a, Index a ~ Int) => Int -> Buffer a -> RenderState a -> RenderState a
 updateRenderState width buf rs =
   let (cache1, rendered) = renderBuffer width buf (rsCache rs)
   in rs
@@ -41,7 +43,7 @@ updateRenderState width buf rs =
       , rsLineCount = length (RenderedBuffer.flatten rendered)
       }
 
-modifyItemRS :: Int -> (Item -> Item) -> RenderState -> RenderState
+modifyItemRS :: (Hashable a, Textual a, Index a ~ Int) => Int -> (Item a -> Item a) -> RenderState a -> RenderState a
 modifyItemRS ix f st =
   let buf'    = Buffer.modifyItem ix f (rsBuffer st)
       cache'  = resizeCache buf' (rsCache st)
@@ -52,7 +54,7 @@ modifyItemRS ix f st =
         , rsLineCount = length (RenderedBuffer.flatten rendered1)
         }
 
-insertItem :: Int -> Item -> RenderState -> RenderState
+insertItem :: (Hashable a, Textual a, Index a ~ Int) => Int -> Item a -> RenderState a -> RenderState a
 insertItem i newItem st =
   let Buffer items = rsBuffer st
       items'       = Seq.insertAt i newItem items
@@ -65,7 +67,7 @@ insertItem i newItem st =
         , rsLineCount = length (RenderedBuffer.flatten rendered1)
         }
 
-deleteItem :: Int -> RenderState -> RenderState
+deleteItem :: (Hashable a, Textual a, Index a ~ Int) => Int -> RenderState a -> RenderState a
 deleteItem i st =
   let Buffer items = rsBuffer st
       items'       = Seq.deleteAt i items
@@ -78,7 +80,7 @@ deleteItem i st =
         , rsLineCount = length (RenderedBuffer.flatten rendered1)
         }
 
-replaceItem :: Int -> Item -> RenderState -> RenderState
+replaceItem :: (Hashable a, Textual a, Index a ~ Int) => Int -> Item a -> RenderState a -> RenderState a
 replaceItem i newItem st =
   let Buffer items = rsBuffer st
       items'       = Seq.update i newItem items
@@ -91,11 +93,11 @@ replaceItem i newItem st =
         , rsLineCount = length (RenderedBuffer.flatten rendered1)
         }
 
-appendItem :: Item -> RenderState -> RenderState
+appendItem :: (Hashable a, Textual a, Index a ~ Int) => Item a -> RenderState a -> RenderState a
 appendItem newItem st =
   insertItem (Seq.length (let Buffer xs = rsBuffer st in xs)) newItem st
 
-clearBuffer :: RenderState -> RenderState
+clearBuffer :: RenderState a -> RenderState a
 clearBuffer st =
   let buf' = Buffer Seq.empty
       cache' = RenderCache Seq.empty
@@ -105,7 +107,7 @@ clearBuffer st =
         , rsLineCount = 0
         }
 
-fromList :: Int -> [Item] -> RenderState
+fromList :: (Hashable a, Textual a, Index a ~ Int) => Int -> [Item a] -> RenderState a
 fromList width xs =
   let buf     = Buffer (Seq.fromList xs)
       cache0  = RenderCache (Seq.replicate (length xs) Nothing)
@@ -118,7 +120,7 @@ fromList width xs =
        , rsLineCount = length (RenderedBuffer.flatten rendered)
        }
 
-fromSeq :: Int -> Seq Item -> RenderState
+fromSeq :: (Hashable a, Textual a, Index a ~ Int) => Int -> Seq (Item a) -> RenderState a
 fromSeq width items =
   let buf     = Buffer items
       cache0  = RenderCache (Seq.replicate (Seq.length items) Nothing)
-- 
cgit v1.2.3