fix some warnings

src/Gyehoek/Scheme/Syntax.hs

@@ -34,7 +34,6 @@ import Data.List (List)
 import Language.SexpGrammar
   ( SexpIso(..), list, el, rest, sym, symbol )
 import Language.SexpGrammar qualified as Sexp
-import Language.Sexp.Located qualified as S
 import Language.SexpGrammar.Generic
 import Effectful
 import GHC.Generics (Generic)
@@ -44,6 +43,7 @@ import Data.List.NonEmpty (NonEmpty)
 import Gyehoek.Sexp qualified
 import Gyehoek.GenSym (Gen)
 import Control.Lens
+import Data.Generics.Labels ()
 import Data.String (IsString)
 import Data.Hashable (Hashable)
 import Data.Data (Data)
@@ -281,6 +281,5 @@ readProgram fp = runFileSystem $
     Gyehoek.Sexp.parseSexps @CommandOrDef (fileName fp) <$> hGetContents h
      >>= either error (pure . MkProgram)
 
-readExp :: IOE :> es => FilePath -> Eff es Program
-readExp fp = readProgram fp <&>
-  (^?! (#commandsAndDefs . _head . _Comm))
+readExp :: IOE :> es => FilePath -> Eff es Exp
+readExp fp = readProgram fp <&> (^?! #commandsAndDefs . _head . #Command)