Use nubOrd when possible

src/Constrained/Core.hs

@@ -22,6 +22,7 @@ module Constrained.Core (
   NonEmpty ((:|)),
   Evidence (..),
   unionWithMaybe,
+  nubOrd,
 ) where
 
 import Constrained.List (
@@ -130,3 +131,13 @@ instance Typeable c => Show (Evidence c) where
 unionWithMaybe :: (a -> a -> a) -> Maybe a -> Maybe a -> Maybe a
 unionWithMaybe f ma ma' = (f <$> ma <*> ma') <|> ma <|> ma'
 
+-- | Strip out duplicates (in n-log(n) time, by building an intermediate Set)
+nubOrd :: Ord a => [a] -> [a]
+nubOrd =
+  loop mempty
+  where
+    loop _ [] = []
+    loop s (a : as)
+      | a `Set.member` s = loop s as
+      | otherwise =
+          let s' = Set.insert a s in s' `seq` a : loop s' as

src/Constrained/NumOrd.hs

@@ -56,7 +56,7 @@
 import Constrained.AbstractSyntax
 import Constrained.Base
 import Constrained.Conformance
-import Constrained.Core (Value (..), unionWithMaybe)
+import Constrained.Core (Value (..), unionWithMaybe, nubOrd)
 import Constrained.FunctionSymbol
 import Constrained.GenT
 import Constrained.Generic
@@ -70,7 +70,7 @@
 import Data.List.NonEmpty (NonEmpty ((:|)))
 import qualified Data.List.NonEmpty as NE
 import Data.Maybe
 import qualified Data.Set as Set
 import Data.Typeable (typeOf)
 import Data.Word
 import GHC.Int
@@ -362,17 +362,6 @@
 -- implementations are found here
 -- =====================================================================
 
--- | Strip out duplicates (in n-log(n) time, by building an intermediate Set)
-nubOrd :: Ord a => [a] -> [a]
-nubOrd =
-  loop mempty
-  where
-    loop _ [] = []
-    loop s (a : as)
-      | a `Set.member` s = loop s as
-      | otherwise =
-          let s' = Set.insert a s in s' `seq` a : loop s' as
-
 -- | Builds a MemberSpec, but returns an Error spec if the list is empty
 nubOrdMemberSpec :: Ord a => String -> [a] -> Specification a
 nubOrdMemberSpec message xs =
@@ -936,7 +925,7 @@
 
   propagateMemberSpec AddW (HOLE :<: i) es =
     memberSpec
-      (nub $ mapMaybe (safeSubtract i) (NE.toList es))
+      (nubOrd $ mapMaybe (safeSubtract i) (NE.toList es))
       ( NE.fromList
           [ "propagateSpecFn on (" ++ show i ++ " +. HOLE)"
           , "The Spec is a MemberSpec = " ++ show es -- show (MemberSpec @HasSpec @TS es)