From 5bf2b08fa9907ad0f2c76364bd72fc800559def0 Mon Sep 17 00:00:00 2001
From: Tissevert <tissevert+devel@marvid.fr>
Date: Wed, 11 Mar 2020 22:35:19 +0100
Subject: [PATCH] Try replacing general monadic type constraint by a definite
 monad stack

---
 src/PDF/Content/Text.hs | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/PDF/Content/Text.hs b/src/PDF/Content/Text.hs
index a818ecf..9826b88 100644
--- a/src/PDF/Content/Text.hs
+++ b/src/PDF/Content/Text.hs
@@ -13,8 +13,8 @@ module PDF.Content.Text (
 
 import Control.Monad (foldM)
 import Control.Monad.Fail (MonadFail(..))
-import Control.Monad.Reader (MonadReader(..), asks, runReaderT)
-import Control.Monad.State (MonadState(..), evalStateT)
+import Control.Monad.Reader (MonadReader(..), ReaderT, asks, runReaderT)
+import Control.Monad.State (MonadState(..), StateT, evalStateT)
 import Data.Map ((!))
 import qualified Data.Map as Map (empty, fromList, singleton)
 import Data.Text (Text, breakOn)
@@ -36,10 +36,10 @@ data ROContext = ROContext {
     , fontSet :: FontSet
   }
 
-type TextContent m = (MonadReader ROContext m, MonadFail m)
-type FontContext m = (MonadState Font m, TextContent m)
+type TextContent m = ReaderT ROContext m
+type FontContext m = StateT Font (TextContent m)
 
-decodeString :: FontContext m => StringObject -> m Text
+decodeString :: MonadFail m => StringObject -> FontContext m Text
 decodeString input = do
   Font {decode} <- get
   either fail return . decode $ toByteString input
@@ -57,24 +57,24 @@ renderText fontSet (Content.Content {contentUnits, Content.indexedInstructions})
   where
     roContext = ROContext {indexedInstructions, fontSet}
 
-renderContentUnit :: TextContent m => ContentUnit -> m (Indexed Text)
+renderContentUnit :: MonadFail m => ContentUnit -> TextContent m (Indexed Text)
 renderContentUnit (GraphicContext graphicContextUnits) =
   mconcat <$> mapM renderGraphicContextUnit graphicContextUnits
 renderContentUnit (TextContext instructionIds) =
   evalStateT (mconcat <$> mapM renderInstructionId instructionIds) emptyFont
 
-renderGraphicContextUnit :: TextContent m => GraphicContextUnit -> m (Indexed Text)
+renderGraphicContextUnit :: MonadFail m => GraphicContextUnit -> TextContent m (Indexed Text)
 renderGraphicContextUnit (GraphicInstruction _) = return Map.empty
 renderGraphicContextUnit (ContentUnit contentUnit) =
   renderContentUnit contentUnit
 
-renderInstructionId :: FontContext m => Id Instruction -> m (Indexed Text)
+renderInstructionId :: MonadFail m => Id Instruction -> FontContext m (Indexed Text)
 renderInstructionId instructionId@(Id n) = toMap <$>
   (asks ((! instructionId) . indexedInstructions) >>= renderInstruction)
   where
     toMap = maybe Map.empty (Map.singleton (Id n))
 
-renderInstruction :: FontContext m => Instruction -> m (Maybe Text)
+renderInstruction :: MonadFail m => Instruction -> FontContext m (Maybe Text)
 renderInstruction (Text Tf, [NameObject fontName, _]) =
   asks ((! fontName) . fontSet) >>= put >> return Nothing