Noodling on the type checker

1 files changed, 6 insertions, 2 deletions

diff --git a/src/HSVIS/Typecheck/Solve.hs b/src/HSVIS/Typecheck/Solve.hs
index 7250e79..250d7e7 100644
--- a/src/HSVIS/Typecheck/Solve.hs
+++ b/src/HSVIS/Typecheck/Solve.hs
@@ -83,7 +83,8 @@ solveConstraints reduce frees subst detect size = \tupcs ->
       errs'' = fmap constrUnequal errs <> errs'
   in trace ("[solver] Solving:" ++ concat ["\n- " ++ pretty a ++ "  ==  " ++ pretty b ++ "  {" ++ pretty r ++ "}" | Constr a b r <- cs]) $
      trace ("[solver] Result: (with " ++ show (length errs'') ++ " errors)" ++
-              concat ["\n- " ++ show v ++ " = " ++ pretty t | (v, t) <- Map.assocs asg'])
+              concat ["\n- " ++ show v ++ " = " ++ pretty t | (v, t) <- Map.assocs asg'] ++
+              "\n... errors: " ++ intercalate ", " (map summariseUE (toList errs'')))
      (asg', errs'')
   where
     reduce' :: Constr t t -> (Bag (Constr v t), Bag (Constr t t))
@@ -136,10 +137,13 @@ solveConstraints reduce frees subst detect size = \tupcs ->
     applyLog ((v, t) : l) m = applyLog l $ Map.insert v (subst m t) m
     applyLog [] m = m
 
-    -- If there are multiple sources for the same cosntraint, only one of them is kept.
+    -- If there are multiple sources for the same constraint, only one of them is kept.
     dedupRCs :: Ord t => [RConstr t] -> [RConstr t]
     dedupRCs = map head . groupBy ((==) `on` rconType) . sortBy (comparing rconType)
 
+    summariseUE (UEUnequal t1 t2 rng) = "({" ++ pretty rng ++ "} " ++ pretty t1 ++ " /= " ++ pretty t2 ++ ")"
+    summariseUE (UERecursive v t2 rng) = "({" ++ pretty rng ++ "} [" ++ show v ++ "] rec in " ++ pretty t2 ++ ")"
+
 minimumByMay :: Foldable t' => (a -> a -> Ordering) -> t' a -> Maybe a
 minimumByMay cmp = foldl' min' Nothing
   where min' mx y = Just $! case mx of