refactor `cached`

1 files changed, 12 insertions, 12 deletions

diff --git a/app/History.hs b/app/History.hs
index 36dc1fc..7ed09bc 100644
--- a/app/History.hs
+++ b/app/History.hs
@@ -348,21 +348,21 @@ fixTreeGrepper treeGrepperResult =
 
 cached :: Binary a => Text -> (Text -> IO a) -> IO a
 cached hash func = do
+  -- FIXME Cache inside Git root
+  --
+  -- The cache location should not be dependant on the current directory, but
+  -- should be placed alongside the `.git` directory.
   cwd <- getCurrentDirectory
   createDirectoryIfMissing True (cwd ++ "/.anissue")
   let file = (cwd ++ "/.anissue/" ++ unpack hash)
-  fileExists <- doesFileExist file
-  if fileExists
-    then do
-      result <- decodeFileOrFail file
-      case result of
-        Left _ -> do
-          blob <- func hash
-          encodeFile file blob
-          pure blob
-        Right blob ->
-          pure blob
-    else do
+  doesFileExist file >>= \case
+    True ->
+      decodeFileOrFail file >>= \case
+        Left _ -> generate file
+        Right blob -> pure blob
+    False -> generate file
+  where
+    generate file = do
       blob <- func hash
       encodeFile file blob
       pure blob