dev:readJournal: assume default file name "-" rather than "(string)" [#2328]

"-" implies data from standard input so "string" is perhaps more
correct, but I think this is a harmless simplification and it
makes `files` output consistent when run by `run`.

hledger-lib/Hledger/Data/Types.hs

@@ -651,7 +651,7 @@ data Journal = Journal {
                                                                       --   any included journal files. The main file is first,
                                                                       --   followed by any included files in the order encountered.
                                                                       --   TODO: FilePath is a sloppy type here, don't assume it's a
-                                                                      --   real file; values like "", "-", "(string)" can be seen
+                                                                      --   real file; values like "" or "-" can be seen
   ,jlastreadtime            :: POSIXTime                              -- ^ when this journal was last read from its file(s)
   -- NOTE: after adding new fields, eg involving account names, consider updating
   -- the Anon instance in Hleger.Cli.Anon

hledger-lib/Hledger/Read.hs

@@ -224,7 +224,7 @@ readJournal :: InputOpts -> Maybe FilePath -> Handle -> ExceptT String IO Journa
 readJournal iopts@InputOpts{strict_, _defer} mpath hdl = do
   let r :: Reader IO = fromMaybe JournalReader.reader $ findReader (mformat_ iopts) mpath
   dbg6IO "readJournal: trying reader" (rFormat r)
-  j <- rReadFn r iopts (fromMaybe "(string)" mpath) hdl
+  j <- rReadFn r iopts (fromMaybe "-" mpath) hdl
   when (strict_ && not _defer) $ liftEither $ journalStrictChecks j
   return j