From c7f3edd6a838e67903c9d6e30cb97f4921adcfb8 Mon Sep 17 00:00:00 2001
From: Andreas Abel <andreas.abel@ifi.lmu.de>
Date: Tue, 2 Jul 2024 19:33:16 +0200
Subject: [PATCH] Tags feature: replace some clumsy code

---
 src/Distribution/Server/Features/Tags/State.hs | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/src/Distribution/Server/Features/Tags/State.hs b/src/Distribution/Server/Features/Tags/State.hs
index 0d7af5063..f92a67346 100644
--- a/src/Distribution/Server/Features/Tags/State.hs
+++ b/src/Distribution/Server/Features/Tags/State.hs
@@ -20,8 +20,9 @@ import Control.Monad (liftM2)
 import Data.SafeCopy (base, deriveSafeCopy)
 import Data.Typeable (Typeable)
 import qualified Data.Char as Char
+import Data.Functor ( (<&>) )
 import Data.Maybe (fromMaybe)
-import Data.List (foldl')
+import Data.List (find, foldl')
 import Control.Monad.State (get, put, modify)
 import Control.Monad.Reader (ask, asks)
 import Control.DeepSeq
@@ -87,13 +88,9 @@ lookupTagAlias tag
          return (Map.lookup tag m)
 
 getTagAlias :: Tag -> Query TagAlias Tag
-getTagAlias tag
-    = do TagAlias m <- ask
-         if tag `elem` Map.keys m
-            then return tag
-            else if tag `Set.member` foldr Set.union Set.empty (Map.elems m)
-                then return $ head (Map.keys $ Map.filter (tag `Set.member`) m)
-                else return tag
+getTagAlias tag = ask <&> \ (TagAlias m) ->
+  if Map.member tag m then tag
+  else maybe tag fst $ find (Set.member tag . snd) $ Map.toList m
 
 emptyPackageTags :: PackageTags
 emptyPackageTags = PackageTags Map.empty Map.empty Map.empty
@@ -279,4 +276,3 @@ $(makeAcidic ''PackageTags ['tagsForPackage
                          ,'lookupReviewTags
                          ,'clearReviewTags
                          ])
-