Don't use keywords for variable names (#2717)

Author: isovector

plugins/hls-tactics-plugin/src/Wingman/Naming.hs

@@ -220,7 +220,29 @@ mkGoodName in_scope (mkTyName -> tn)
   . foldMap (\n -> bool (pure n) mempty $ check n)
   $ tn <> fmap (<> "'") tn
   where
-    check n = S.member (mkVarOcc n) in_scope
+    check n = S.member (mkVarOcc n) $ illegalNames <> in_scope
+
+
+illegalNames :: Set OccName
+illegalNames = S.fromList $ fmap mkVarOcc
+  [ "case"
+  , "of"
+  , "class"
+  , "data"
+  , "do"
+  , "type"
+  , "if"
+  , "then"
+  , "else"
+  , "let"
+  , "in"
+  , "mdo"
+  , "newtype"
+  , "proc"
+  , "rec"
+  , "where"
+  ]
+
 
 
 ------------------------------------------------------------------------------

plugins/hls-tactics-plugin/test/CodeAction/DestructSpec.hs

@@ -20,6 +20,7 @@ spec = do
     destructTest "b"     7 10 "DestructTyFam"
     destructTest "b"     7 10 "DestructDataFam"
     destructTest "b"    17 10 "DestructTyToDataFam"
+    destructTest "t"     6 10 "DestructInt"
 
   describe "layout" $ do
     destructTest "b"  4  3 "LayoutBind"

plugins/hls-tactics-plugin/test/golden/DestructInt.expected.hs

@@ -0,0 +1,7 @@
+import Data.Int
+
+data Test = Test Int32
+
+test :: Test -> Int32
+test (Test in') = _w0
+

plugins/hls-tactics-plugin/test/golden/DestructInt.hs

@@ -0,0 +1,7 @@
+import Data.Int
+
+data Test = Test Int32
+
+test :: Test -> Int32
+test t = _
+