If your finalization step depends on the result of your action, bracket is not an appropriate choice. It is for resources that are known at the time they are acquired. On Sat, Mar 26, 2016 at 11:59 AM PICCA Frederic-Emmanuel < frederic-emmanuel.picca@synchrotron-soleil.fr> wrote:
Hello, I try to write a sort of withxxx method whcih release a file
withH5File :: FilePath -> (HId_t -> IO r) -> IO r withH5File name = bracket (withCString name acquire) h5f_close where acquire file = h5f_open file h5f_ACC_RDONLY h5p_DEFAULT
In my case h5f_open return a HId_t value (HId_t Int) If something went wrong the returned value is negativ. In that case I do not need to h5f_close the file but instead return an error
My question is how should I write the bracket part when the finaliser (h5f_close) depends on the result of the acquire part.
thanks for your help
Frederic _______________________________________________ Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners