From fee42779f3ab78260af1a98ca16787364f81cf11 Mon Sep 17 00:00:00 2001
From: Chris Penner <christopher.penner@gmail.com>
Date: Thu, 31 Aug 2023 15:11:18 -0700
Subject: [PATCH] Apply perf optimization: don't call callback unless there are
 changes

---
 parser-typechecker/src/U/Codebase/Branch/Diff.hs | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/parser-typechecker/src/U/Codebase/Branch/Diff.hs b/parser-typechecker/src/U/Codebase/Branch/Diff.hs
index 028c5ef515..e816daf034 100644
--- a/parser-typechecker/src/U/Codebase/Branch/Diff.hs
+++ b/parser-typechecker/src/U/Codebase/Branch/Diff.hs
@@ -222,11 +222,10 @@ streamNameChanges namePrefix (TreeDiff (DefinitionDiffs {termDiffs, typeDiffs} :
             let name = appendName ns
              in (listifyNames name $ adds diff, listifyNames name $ removals diff)
   let nameChanges = NameChanges {termNameAdds, termNameRemovals, typeNameAdds, typeNameRemovals}
-  acc <- f namePrefix nameChanges
-  -- acc <-
-  --   if nameChanges == mempty
-  --     then pure mempty
-  --     else f namePrefix nameChanges
+  acc <-
+    if nameChanges == mempty
+      then pure mempty
+      else f namePrefix nameChanges
   childAcc <-
     children
       & ifoldMapM