Split CExpr and SExpr into different ADTs (WIP)

dex.cabal

@@ -82,7 +82,8 @@ library
                      , SourceIdTraversal
                      , TopLevel
                      -- , Transpose
-                     , Types.Core
+                     , Types.Simple
+                     , Types.Complicated
                      , Types.Imp
                      , Types.Primitives
                      , Types.Source

src/lib/Core.hs

@@ -35,7 +35,8 @@ import qualified Data.Map.Strict       as M
 import Name
 import Err
 
-import Types.Core
+import Types.Complicated
+import Types.Simple
 import Types.Top
 import Types.Imp
 import Types.Primitives

src/lib/Name.hs

@@ -23,10 +23,8 @@ import Control.Monad.Writer.Strict
 import Control.Monad.State.Strict
 import qualified Data.HashMap.Strict as HM
 import qualified Data.Map.Strict as M
-import Data.Bits
 import Data.Functor ((<&>))
 import Data.Foldable (toList, foldl')
-import Data.Maybe (fromJust, catMaybes)
 import Data.Hashable
 import Data.Kind (Type)
 import Data.Function ((&))
@@ -2192,7 +2190,7 @@ absurdNameFunction :: Name VoidS -> a
 absurdNameFunction v = error $ "Void names shouldn't exist: " ++ show v
 
 scopeFragToSubstFrag :: forall v i i' o
-                      . (forall c. Name (i:=>:i') -> v o)
+                      . (Name (i:=>:i') -> v o)
                      -> ScopeFrag i i' -> SubstFrag v i i' o
 scopeFragToSubstFrag f (UnsafeScopeFromSubst m) = fmapSubstFrag (\n _ -> f n) m
 
@@ -2220,7 +2218,7 @@ newNames n = do
   let bs = unsafeListToNest $ map UnsafeMakeBinder ns
   unsafeCoerceE $ Abs bs $ ListE vs
 
-withFresh :: forall n c a. (Distinct n)
+withFresh :: forall n a. (Distinct n)
           => NameHint -> Scope n
           -> (forall l. DExt n l => NameBinder n l -> a) -> a
 withFresh hint (Scope (UnsafeMakeScopeFrag scope)) cont =
@@ -2749,7 +2747,7 @@ instance BindsNames (SubstPair v o) where
 
 -- === instances ===
 
-instance (forall c. Pretty (v n)) => Pretty (SubstItem v n) where
+instance Pretty (v n) => Pretty (SubstItem v n) where
   pretty (SubstItem _ val) = pretty val
 
 instance SinkableE v => SinkableE (SubstFrag v i i') where

src/lib/QueryTypePure.hs

@@ -7,7 +7,8 @@
 module QueryTypePure where
 
 import Types.Primitives
-import Types.Core
+import Types.Simple
+import Types.Complicated
 import Types.Top
 import Name