fix build warnings in all GHC versions

hledger-lib/Hledger/Read.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE ScopedTypeVariables #-}
 {-| 
 
 This is the entry point to hledger's reading system, which can read
@@ -25,6 +26,7 @@ module Hledger.Read (
        tests_Hledger_Read,
 )
 where
+import qualified Control.Exception as C
 import Control.Monad.Error
 import Data.List
 import Data.Maybe
@@ -75,9 +77,12 @@ defaultJournalPath = do
   s <- envJournalPath
   if null s then defaultJournalPath else return s
     where
-      envJournalPath = getEnv journalEnvVar `catch` (\_ -> getEnv journalEnvVar2 `catch` (\_ -> return ""))
+      envJournalPath =
+        getEnv journalEnvVar
+         `C.catch` (\(_::C.IOException) -> getEnv journalEnvVar2
+                                            `C.catch` (\(_::C.IOException) -> return ""))
       defaultJournalPath = do
-                  home <- getHomeDirectory `catch` (\_ -> return "")
+                  home <- getHomeDirectory `C.catch` (\(_::C.IOException) -> return "")
                   return $ home </> journalDefaultFilename
 
 -- | Read the default journal file specified by the environment, or raise an error.

hledger-lib/Hledger/Read/JournalReader.hs

@@ -34,6 +34,7 @@ module Hledger.Read.JournalReader (
   tests_Hledger_Read_JournalReader
 )
 where
+import qualified Control.Exception as C
 import Control.Monad
 import Control.Monad.Error
 import Data.Char (isNumber)
@@ -185,8 +186,8 @@ includedirective = do
                 Right (ju,_) -> combineJournalUpdates [return $ journalAddFile (filepath,txt), ju] `catchError` (throwError . (inIncluded ++))
                 Left err     -> throwError $ inIncluded ++ show err
       where readFileOrError pos fp =
-                ErrorT $ liftM Right (readFile fp) `catch`
-                  \err -> return $ Left $ printf "%s reading %s:\n%s" (show pos) fp (show err)
+                ErrorT $ liftM Right (readFile fp) `C.catch`
+                  \e -> return $ Left $ printf "%s reading %s:\n%s" (show pos) fp (show (e::C.IOException))
 
 journalAddFile :: (FilePath,String) -> Journal -> Journal
 journalAddFile f j@Journal{files=fs} = j{files=fs++[f]}

hledger/Hledger/Cli/Add.hs

@@ -10,7 +10,7 @@ informational messages are mostly written to stderr rather than stdout.
 
 module Hledger.Cli.Add
 where
-import Control.Exception (throw)
+import Control.Exception as C
 import Control.Monad
 import Control.Monad.Trans (liftIO)
 import Data.Char (toUpper)
@@ -56,7 +56,7 @@ add opts j
     ++"To stop adding transactions, enter . at a date prompt, or control-d/control-c."
   today <- getCurrentDay
   getAndAddTransactions j opts today
-        `catch` (\e -> unless (isEOFError e) $ ioError e)
+        `C.catch` (\e -> unless (isEOFError e) $ ioError e)
       where f = journalFilePath j
 
 -- | Read a number of transactions from the command line, prompting,
@@ -197,7 +197,7 @@ askFor prompt def validator = do
     Nothing -> return input
     where
         showdef s = " [" ++ s ++ "]"
-        eofErr = throw $ mkIOError eofErrorType "end of input" Nothing Nothing
+        eofErr = C.throw $ mkIOError eofErrorType "end of input" Nothing Nothing
 
 -- | Append this transaction to the journal's file, and to the journal's
 -- transaction list.

hledger/Hledger/Cli/Balance.hs

@@ -107,7 +107,6 @@ import Hledger
 import Prelude hiding (putStr)
 import Hledger.Utils.UTF8IOCompat (putStr)
 import Hledger.Data.FormatStrings
-import qualified Hledger.Data.FormatStrings as Format
 import Hledger.Cli.Options
 
 

hledger/Hledger/Cli/Options.hs

@@ -1,4 +1,4 @@
-{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TemplateHaskell, ScopedTypeVariables #-}
 {-|
 
 Command-line options for the hledger program, and option-parsing utilities.
@@ -7,6 +7,7 @@ Command-line options for the hledger program, and option-parsing utilities.
 
 module Hledger.Cli.Options
 where
+import Control.Exception as C
 import Data.List
 import Data.List.Split
 import Data.Maybe
@@ -370,8 +371,8 @@ getHledgerProgramsInPath = do
     where
       hledgerprog = string progname >> char '-' >> many1 (letter <|> char '-') >> eof
 
-getEnvSafe v = getEnv v `catch` (\_ -> return "")
-getDirectoryContentsSafe d = getDirectoryContents d `catch` (\_ -> return [])
+getEnvSafe v = getEnv v `C.catch` (\(_::C.IOException) -> return "")
+getDirectoryContentsSafe d = getDirectoryContents d `C.catch` (\(_::C.IOException) -> return [])
 
 -- | Convert possibly encoded option values to regular unicode strings.
 decodeRawOpts = map (\(name,val) -> (name, fromSystemString val))

hledger/Hledger/Cli/Utils.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE ScopedTypeVariables #-}
 {-|
 
 Utilities for top-level modules and ghci. See also Hledger.Read and
@@ -20,7 +21,7 @@ module Hledger.Cli.Utils
      Test(TestList),
     )
 where
-import Control.Exception
+import Control.Exception as C
 import Data.List
 import Data.Maybe
 import Safe (readMay)
@@ -95,7 +96,7 @@ journalSpecifiedFileIsNewer Journal{filereadtime=tread} f = do
 fileModificationTime :: FilePath -> IO ClockTime
 fileModificationTime f
     | null f = getClockTime
-    | otherwise = getModificationTime f `Prelude.catch` \_ -> getClockTime
+    | otherwise = getModificationTime f `C.catch` \(_::C.IOException) -> getClockTime
 
 -- | Attempt to open a web browser on the given url, all platforms.
 openBrowserOn :: String -> IO ExitCode
@@ -135,7 +136,7 @@ writeFileWithBackup :: FilePath -> String -> IO ()
 writeFileWithBackup f t = backUpFile f >> writeFile f t
 
 readFileStrictly :: FilePath -> IO String
-readFileStrictly f = readFile f >>= \s -> Control.Exception.evaluate (length s) >> return s
+readFileStrictly f = readFile f >>= \s -> C.evaluate (length s) >> return s
 
 -- | Back up this file with a (incrementing) numbered suffix, or give an error.
 backUpFile :: FilePath -> IO ()