Effects: StorePath: reduce newtype accessor

Author: Anton-Latukha

src/Nix/Builtins.hs

@@ -1122,7 +1122,7 @@ toFileNix name s =
         (stringIgnoreContext s')
 
     let
-      t  = toText $ unStorePath mres
+      t  = toText @FilePath $ coerce mres
       sc = StringContext t DirectPath
 
     toValue $ makeNixStringWithSingletonContext t sc

src/Nix/Convert.hs

@@ -195,9 +195,8 @@ instance ( Convertible e t f m
     \case
       NVStr' ns -> pure $ pure ns
       NVPath' p ->
-        fmap
-          (pure . (\s -> makeNixStringWithSingletonContext s (StringContext s DirectPath)) . toText . unStorePath)
-          (addPath p)
+        (\path -> pure $ makeNixStringWithSingletonContext path (StringContext path DirectPath)) . toText @FilePath . coerce <$>
+          addPath p
       NVSet' s _ ->
         maybe
           stub
@@ -368,7 +367,7 @@ instance Convertible e t f m
 
 instance Convertible e t f m
   => ToValue StorePath m (NValue' t f m (NValue t f m)) where
-  toValue = toValue . Path . unStorePath
+  toValue = toValue @Path . coerce
 
 instance ( Convertible e t f m
          )

src/Nix/Effects.hs

@@ -41,7 +41,7 @@ import qualified System.Nix.Store.Remote       as Store.Remote
 import qualified System.Nix.StorePath          as Store
 
 -- | A path into the nix store
-newtype StorePath = StorePath { unStorePath :: FilePath }
+newtype StorePath = StorePath FilePath
 
 
 -- All of the following type classes defer to the underlying 'm'.

src/Nix/Effects/Derivation.hs

@@ -75,7 +75,7 @@ writeDerivation drv@Derivation{inputs, name} = do
   let (inputSrcs, inputDrvs) = inputs
   references <- Set.fromList <$> traverse parsePath (Set.toList $ inputSrcs <> Set.fromList (Map.keys inputDrvs))
   path <- addTextToStore (Text.append name ".drv") (unparseDrv drv) (S.fromList $ Set.toList references) False
-  parsePath $ toText $ unStorePath path
+  parsePath $ toText @FilePath $ coerce path
 
 -- | Traverse the graph of inputDrvs to replace fixed output derivations with their fixed output hash.
 -- this avoids propagating changes to their .drv when the output hash stays the same.
@@ -275,7 +275,7 @@ defaultDerivationStrict val = do
         pure $ drv
           { inputs
           , outputs = outputs'
-          , env = ifNotJsonModEnv $ (outputs' <>)
+          , env = ifNotJsonModEnv (outputs' <>)
           }
 
     drvPath <- pathToText <$> writeDerivation drv'

src/Nix/Json.hs

@@ -42,8 +42,8 @@ nvalueToJSON = \case
       (HM.lookup "outPath" m)
   NVPath p ->
     do
-      fp <- lift $ unStorePath <$> addPath p
-      addSingletonStringContext $ StringContext (toText fp) DirectPath
+      fp <- lift $ coerce <$> addPath p
+      addSingletonStringContext $ StringContext (toText @FilePath fp) DirectPath
       pure $ A.toJSON fp
   v -> lift $ throwError $ CoercionToJson v