fix formatter

src/Juvix/Compiler/Concrete/Language.hs

@@ -978,7 +978,10 @@ data Iterator s = Iterator
   { _iteratorName :: IdentifierType s,
     _iteratorInitializers :: [Initializer s],
     _iteratorRanges :: [Range s],
-    _iteratorBody :: ExpressionType s
+    _iteratorBody :: ExpressionType s,
+    -- | Due to limitations of the pretty printing algorithm, we store whether
+    -- the iterator was surrounded by parentheses in the code.
+    _iteratorParens :: Bool
   }
 
 deriving stock instance
@@ -1192,7 +1195,7 @@ expressionAtomicity e = case sing :: SStage s of
   SScoped -> atomicity e
 
 instance HasAtomicity (Iterator s) where
-  atomicity = const (Aggregate appFixity)
+  atomicity = const Atom
 
 instance HasAtomicity (Case s) where
   atomicity = const Atom

src/Juvix/Compiler/Concrete/Pretty/Base.hs

@@ -764,9 +764,11 @@ instance (SingI s) => PrettyCode (Iterator s) where
     is <- mapM ppCode _iteratorInitializers
     rngs <- mapM ppCode _iteratorRanges
     let is' = if null is then Nothing else Just (parens (hsep (punctuate semi is)))
-        rngs' = if null rngs then mempty else parens (hsep (punctuate semi rngs))
+        rngs' = if null rngs then Nothing else Just (parens (hsep (punctuate semi rngs)))
     b <- ppExpression _iteratorBody
-    return $ hang' (n <+> is' <?+> rngs' <> oneLineOrNextNoIndent b)
+    return $
+      parensIf _iteratorParens $
+        hang' (n <+?> is' <+?> rngs' <> oneLineOrNextNoIndent b)
 
 instance (SingI s) => PrettyCode (Initializer s) where
   ppCode Initializer {..} = do

src/Juvix/Compiler/Concrete/Translation/FromParsed/Analysis/Scoping.hs

@@ -1301,6 +1301,7 @@ checkIterator iter = do
     rngpats' <- mapM checkParsePatternAtoms rngpats
     let _iteratorInitializers = zipWithExact Initializer inipats' inivals'
         _iteratorRanges = zipWithExact Range rngpats' rngvals'
+        _iteratorParens = iter ^. iteratorParens
     _iteratorBody <- checkParseExpressionAtoms (iter ^. iteratorBody)
     return Iterator {..}
 
@@ -1343,6 +1344,7 @@ checkParens e@(ExpressionAtoms as _) = case as of
     scopedId <- checkName s
     let scopedIdenNoFix = idenOverName (set S.nameFixity Nothing) scopedId
     return (ExpressionParensIdentifier scopedIdenNoFix)
+  AtomIterator i :| [] -> ExpressionIterator . set iteratorParens True <$> checkIterator i
   AtomCase c :| [] -> ExpressionCase . set caseParens True <$> checkCase c
   _ -> checkParseExpressionAtoms e
 

src/Juvix/Compiler/Concrete/Translation/FromSource.hs

@@ -592,6 +592,7 @@ iterator = do
             rparen
             return rngs
   _iteratorBody <- parseExpressionAtoms
+  let _iteratorParens = False
   return Iterator {..}
   where
     initializer :: ParsecS r (Initializer 'Parsed)

tests/Compilation/positive/test054.juvix

@@ -51,7 +51,8 @@ main :=
   sum lst
     + sum' lst
     + fst (for (a, b := 0, 0) (x in lst) b + x, a)
-    + (for2 (acc := 0) (x in lst; y in 1 :: 2 :: nil) acc + x + y)
+    + (for2 (acc := 0) (x in lst; y in 1 :: 2 :: nil)
+         acc + x + y)
     + fst
       (myzip2 (a := 0; b := 0) (x in lst; y in reverse lst)
          a + x * y, b + y)