Evaluate Module and Program using Imperative.

src/Data/Syntax.hs

@@ -124,14 +124,7 @@ instance Ord1 Program where liftCompare = genericLiftCompare
 instance Show1 Program where liftShowsPrec = genericLiftShowsPrec
 
 instance Evaluatable Program where
-  eval (Program xs) = eval' xs
-    where
-      eval' [] = unit >>= interface
-      eval' [x] = subtermValue x >>= interface
-      eval' (x:xs) = do
-        _ <- subtermValue x
-        env <- getGlobalEnv
-        localEnv (envUnion env) (eval' xs)
+  eval (Program xs) = runImperative $ foldMap (Imperative . subtermValue) xs
 
 -- | An accessibility modifier, e.g. private, public, protected, etc.
 newtype AccessibilityModifier a = AccessibilityModifier ByteString

src/Data/Syntax/Declaration.hs

@@ -161,14 +161,7 @@ instance Show1 Module where liftShowsPrec = genericLiftShowsPrec
 -- We need to ensure that all input files have aggregated their content into
 -- a coherent module before we begin evaluating a module.
 instance Evaluatable Module where
-  eval (Module _ xs) = eval' xs
-    where
-    eval' [] = unit >>= interface
-    eval' [x] = subtermValue x >>= interface
-    eval' (x:xs) = do
-      _ <- subtermValue x
-      env <- getGlobalEnv
-      localEnv (envUnion env) (eval' xs)
+  eval (Module _ xs) = runImperative $ foldMap (Imperative . subtermValue) xs
 
 -- | A decorator in Python
 data Decorator a = Decorator { decoratorIdentifier :: !a, decoratorParamaters :: ![a], decoratorBody :: !a }