#12096: Attach stacktrace information to SomeException -------------------------------------+------------------------------------- Reporter: ndtimofeev | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Core Libraries | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by ezyang): I know that `catchIO` and then `throwIO` if the `IOError` does not match a predicate is a common idiom. It's somewhat difficult to regex for them but if you grep for `throwIO` with a reference to a variable, there are tons and tons of them. Here are three random ones I picked out: {{{ -- system-fileio removeTree root = do items <- listDirectory root forM_ items $ \item -> Exc.catch (removeFile item) (\exc -> do isDir <- isRealDir item if isDir then removeTree item else Exc.throwIO (exc :: IOError)) -- HsSVN do err <- wrapSvnError =<< _fs_commit_txn conflictPathPtrPtr reposPtr newRevPtr txnPtr poolPtr case err of Nothing -> liftM (Right . fromIntegral) (peek newRevPtr) Just e -> if svnErrCode e == FsConflict then return . Left =<< peekCString =<< peek conflictPathPtrPtr else throwIO e -- DPM (Darcs.Lock.withLock fname (writeIORef ref True >> io)) `catch` (\ (e::SomeException) -> do b <- readIORef ref if b then throwIO e else failIO ("Could not obtain lock " ++ show fname ++ ", aborting.")) }}} I just grepped for `throwIO` and picked out three random examples that looked like they were rethrowing. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12096#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler