Add potentially isolated nodes in dependency builder

src/Juvix/Compiler/Internal/Extra/DependencyBuilder.hs

@@ -56,6 +56,17 @@ addStartNode n = modify (HashSet.insert n)
 addEdgeMay :: (Member (State DependencyGraph) r) => Maybe Name -> Name -> Sem r ()
 addEdgeMay mn1 n2 = whenJust mn1 $ \n1 -> addEdge n1 n2
 
+addNode :: (Member (State DependencyGraph) r) => Name -> Sem r ()
+addNode n =
+  modify
+    ( HashMap.alter
+        ( \case
+            Just x -> Just x
+            Nothing -> Just (mempty :: HashSet Name)
+        )
+        n
+    )
+
 addEdge :: (Member (State DependencyGraph) r) => Name -> Name -> Sem r ()
 addEdge n1 n2 =
   modify
@@ -179,6 +190,7 @@ goFunctionDefHelper ::
   FunctionDef ->
   Sem r ()
 goFunctionDefHelper f = do
+  addNode (f ^. funDefName)
   checkStartNode (f ^. funDefName)
   when (f ^. funDefInstance) $
     goInstance f

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

@@ -244,9 +244,13 @@ instance PrettyCode FunctionDef where
         <?+> funDefName'
           <+> kwColon
           <+> funDefType'
-            <> line
+            <> hardline
             <> vsep (toList clauses')
 
+instance PrettyCode PreLetStatement where
+  ppCode = \case
+    PreLetFunctionDef f -> ppCode f
+
 instance PrettyCode FunctionClause where
   ppCode c = do
     funName <- ppCode (c ^. clauseName)

tests/positive/issue2373/Main.juvix

@@ -1,8 +1,10 @@
 module Main;
 
 import Stdlib.Data.Nat open;
+import Stdlib.Data.Bool open;
 
 main : Nat :=
   let
+    y : Nat := 0;
     x : _ := 0;
   in x;