lib: factor out parsing child journal into separate function

hledger-lib/Hledger/Read/JournalReader.hs

@@ -196,9 +196,16 @@ includedirectivep = do
   curdir <- lift $ expandPath (takeDirectory $ sourceName parentpos) ""
                    `orRethrowIOError` (show parentpos ++ " locating " ++ filename)
    -- </> correctly handles case when 'filename' is absolute
-  let filepath = curdir </> filename
-  -- read child input
-  childInput <- lift $ readFilePortably filepath `orRethrowIOError` (show parentpos ++ " reading " ++ filepath)
+  let filepaths = [curdir </> filename]
+  -- read child inputs
+  forM_ filepaths $ parseChild parentpos
+
+  void newline
+
+  where
+    parseChild parentpos filepath = do
+        childInput <- lift $ readFilePortably filepath
+                             `orRethrowIOError` (show parentpos ++ " reading " ++ filepath)
 
         -- save parent state
         parentParserState <- getParserState
@@ -224,8 +231,6 @@ includedirectivep = do
         put $ updatedChildj <> parentj
         -- discard child's parse info, prepend its (reversed) list data, combine other fields
 
-  void newline
-
 
 newJournalWithParseStateFrom :: Journal -> Journal
 newJournalWithParseStateFrom j = mempty{