From 8caee1226dcc9566649358f6af1f177e7341c76c Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@me.com>
Date: Mon, 10 Dec 2018 09:53:12 -0500
Subject: [PATCH] Evaluate Statement.Assignment using ref.

---
 src/Data/Syntax/Statement.hs | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/src/Data/Syntax/Statement.hs b/src/Data/Syntax/Statement.hs
index a0e467166..61a1c5b97 100644
--- a/src/Data/Syntax/Statement.hs
+++ b/src/Data/Syntax/Statement.hs
@@ -173,26 +173,23 @@ instance Ord1 Assignment where liftCompare = genericLiftCompare
 instance Show1 Assignment where liftShowsPrec = genericLiftShowsPrec
 
 instance Evaluatable Assignment where
-  eval eval _ Assignment{..} = do
-    lhs <- eval assignmentTarget
+  eval eval ref Assignment{..} = do
+    lhs <- ref assignmentTarget
     rhs <- eval assignmentValue
 
-    case lhs of
-      Rval val -> throwEvalError (DerefError val)
-      LvalMember lhsSlot -> do
-        case declaredName assignmentValue of
-          Just rhsName -> do
-            assocScope <- associatedScope (Declaration rhsName)
-            case assocScope of
-              Just assocScope' -> do
-                objectScope <- newScope (Map.singleton Import [ assocScope' ])
-                putSlotDeclarationScope lhsSlot (Just objectScope) -- TODO: not sure if this is right
-              Nothing ->
-                pure ()
+    case declaredName assignmentValue of
+      Just rhsName -> do
+        assocScope <- associatedScope (Declaration rhsName)
+        case assocScope of
+          Just assocScope' -> do
+            objectScope <- newScope (Map.singleton Import [ assocScope' ])
+            putSlotDeclarationScope lhs (Just objectScope) -- TODO: not sure if this is right
           Nothing ->
             pure ()
-        assign lhsSlot =<< Abstract.value rhs
-        pure (LvalMember lhsSlot)
+      Nothing ->
+        pure ()
+    assign lhs =<< Abstract.value rhs
+    pure (LvalMember lhs)
 
 instance Tokenize Assignment where
   -- Should we be using 'assignmentContext' in here?