Use catch from Control.Exception, avoid warning.

jgm · Oct 24, 2012 · 939f87e · 939f87e
1 parent 5489cef
commit 939f87e
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Showing 4 changed files with 38 additions and 11 deletions.
diff --git a/Yst/Build.hs b/Yst/Build.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ScopedTypeVariables #-}
 {-
 Copyright (C) 2009 John MacFarlane <jgm@berkeley.edu>
 
@@ -32,12 +33,14 @@ import System.Time (ClockTime(..))
 -- So we use System.IO.UTF8 only if we have an earlier version
 #if MIN_VERSION_base(4,2,0)
 import System.IO (hPutStrLn)
+import Prelude hiding (catch)
 #else
-import Prelude hiding (readFile, putStrLn, print, writeFile)
+import Prelude hiding (readFile, putStrLn, print, writeFile, catch)
 import System.IO.UTF8
 #endif
 import System.IO (stderr)
 import Control.Monad
+import Control.Exception (catch, SomeException)
 
 findSource :: Site -> FilePath -> IO FilePath
 findSource = searchPath . sourceDir
@@ -79,7 +82,8 @@ updateFile site file = do
   let destpath = deployDir site </> file
   srcpath <- searchPath (filesDir site) file
   srcmod <- getModificationTime srcpath
-  destmod <- catch (getModificationTime destpath) (\_ -> return $ TOD 0 0)
+  destmod <- catch (getModificationTime destpath)
+                   (\(_::SomeException) -> return $ TOD 0 0)
   if srcmod > destmod
      then do
        createDirectoryIfMissing True $ takeDirectory destpath
@@ -98,7 +102,8 @@ updatePage site page = do
       hPutStrLn stderr $ "Aborting!  Cannot build " ++ destpath
       exitWith $ ExitFailure 3
   depsmod <- mapM getModificationTime deps
-  destmod <- catch (getModificationTime destpath) (\_ -> return $ TOD 0 0)
+  destmod <- catch (getModificationTime destpath)
+                   (\(_::SomeException) -> return $ TOD 0 0)
   if maximum depsmod > destmod
      then do
        createDirectoryIfMissing True $ takeDirectory destpath

diff --git a/Yst/CSV.hs b/Yst/CSV.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ScopedTypeVariables #-}
 {-
 Copyright (C) 2009 John MacFarlane <jgm@berkeley.edu>
 
@@ -24,14 +25,19 @@ import Text.CSV
 -- Note: ghc >= 6.12 (base >=4.2) supports unicode through iconv
 -- So we use System.IO.UTF8 only if we have an earlier version
 #if MIN_VERSION_base(4,2,0)
+import Prelude hiding (catch)
 #else
-import Prelude hiding (readFile)
+import Prelude hiding (readFile, catch)
 import System.IO.UTF8
 #endif
+import Control.Exception (catch, SomeException)
 
 readCSVFile :: FilePath -> IO Node
-readCSVFile f = catch (readFile f >>= return . csvToNode . parseCSV' f . stripBlanks . filter (/='\r'))
-                   (\e -> errorExit 11 ("Error parsing " ++ f ++ ": " ++ show e) >> return NNil)
+readCSVFile f = catch (toNode `fmap` readFile f)
+                      (\(e::SomeException) -> do
+                         errorExit 11 ("Error parsing " ++ f ++ ": " ++ show e)
+                         return NNil)
+  where toNode = csvToNode . parseCSV' f . stripBlanks . filter (/='\r')
 
 parseCSV' :: FilePath -> String -> CSV
 parseCSV' f s = case parseCSV f s of

diff --git a/Yst/Data.hs b/Yst/Data.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE ScopedTypeVariables, FlexibleContexts #-}
 {-
 Copyright (C) 2009 John MacFarlane <jgm@berkeley.edu>
 
@@ -30,18 +30,26 @@ import Data.Maybe (fromMaybe)
 import Data.List (sortBy, nub, isPrefixOf)
 import Text.ParserCombinators.Parsec
 import System.FilePath (takeExtension)
+import Prelude hiding (catch)
+import Control.Exception (catch, SomeException)
 
 findData :: Site -> FilePath -> IO FilePath
 findData = searchPath . dataDir
 
 getData :: Site -> DataSpec -> IO Node
 getData site (DataFromFile file opts) = do
   raw <- catch (findData site file >>= readDataFile)
-          (\e -> errorExit 15 ("Error reading data from " ++ file ++ ": " ++ show e) >> return undefined)
+               (\(e::SomeException) -> do
+                  errorExit 15 ("Error reading data from " ++ file ++ ": "
+                     ++ show e)
+                  return undefined)
   return $ foldl applyDataOption raw opts
 getData site (DataFromSqlite3 database query opts) = do
   raw <- catch (findData site database >>= \d -> readSqlite3 d query)
-          (\e -> errorExit 15 ("Error reading Sqlite3 database from " ++ database ++ ": " ++ show e) >> return undefined)
+               (\(e::SomeException) -> do
+                  errorExit 15 ("Error reading Sqlite3 database from " ++
+                    database ++ ": " ++ show e)
+                  return undefined)
   return $ foldl applyDataOption raw opts
 getData _ (DataConstant n) = return n
 

diff --git a/Yst/Yaml.hs b/Yst/Yaml.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ScopedTypeVariables #-}
 {-
 Copyright (C) 2009 John MacFarlane <jgm@berkeley.edu>
 
@@ -26,6 +27,8 @@ import Data.Time
 import System.Locale (defaultTimeLocale)
 import Codec.Binary.UTF8.String (encodeString, decodeString)
 import qualified Data.ByteString.Char8 as B (ByteString, readFile, filter)
+import Prelude hiding (catch)
+import Control.Exception (catch, SomeException)
 
 -- Note: Syck isn't unicode aware, so we use parseYamlBytes and do our
 -- own encoding and decoding.
@@ -39,8 +42,13 @@ packBuf :: String -> Buf
 packBuf = Data.Yaml.Syck.packBuf . encodeString
 
 readYamlFile :: FilePath -> IO Node
-readYamlFile f = catch (B.readFile f >>= parseYamlBytes . B.filter (/='\r') >>= return . yamlNodeToNode)
-                   (\e -> errorExit 11 ("Error parsing " ++ f ++ ": " ++ show e) >> return NNil)
+readYamlFile f = catch (B.readFile f
+                        >>= parseYamlBytes . B.filter (/='\r')
+                        >>= return . yamlNodeToNode)
+                        (\(e::SomeException) -> do
+                             errorExit 11 ("Error parsing " ++ f ++ ": " ++
+                                show e)
+                             return NNil)
 
 yamlNodeToNode :: YamlNode -> Node
 yamlNodeToNode n =