newsham:
I'm starting to wonder if this isn't an issue with Data.ByteString.Lazy.Char8.{read,write}File.
This simple test case fails:
module Main where import qualified Data.ByteString.Lazy.Char8 as B main = do print =<< B.readFile "xxx" B.writeFile "xxx" =<< B.readFile "test.hs"
If you replace B.readFile with readFile and B.writeFile with writeFile it works properly. ByteString bug?
Ah, that would be a bug in older ByteString implementations, that were a bit incautious about closing handles. This example works for me with bytestring-0.9.1.0 You're looking for a post-Dec 19, 2007 release, after the patch, Wed Dec 19 22:06:13 PST 2007 Don Stewart * For lazy IO operations, be sure to hClose the resource on EOF -- Don