Re: [Haskell-cafe] Handling exceptions or gracefully releasing resources
Everything that Johan Tibell said + you may be interested in the resourcet package [1] (which is used by conduit to handle resources). Cheers, [1] http://hackage.haskell.org/package/resourcet On Tue, Jan 29, 2013 at 8:59 PM, Thiago Negri evoh...@gmail.com wrote: `Control.Exception.bracket` is a nice function to acquire and release a resource in a small context. But, how should I handle resources that are hold for a long time? Should I put `Control.Exception.finally` on every single line of my finalizers? What exceptions may occur on an IO operation? Every IO function has the risk of throwing an exception? Thanks, Thiago. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Handling exceptions or gracefully releasing resources
Felipe, I'm trying to use your Hipmunk package. :) The resources I need to keep around are the objects used for the simulation. Do you recomend using resourcet to handle this or something else? Thanks. 2013/1/30 Felipe Almeida Lessa felipe.le...@gmail.com Everything that Johan Tibell said + you may be interested in the resourcet package [1] (which is used by conduit to handle resources). Cheers, [1] http://hackage.haskell.org/package/resourcet On Tue, Jan 29, 2013 at 8:59 PM, Thiago Negri evoh...@gmail.com wrote: `Control.Exception.bracket` is a nice function to acquire and release a resource in a small context. But, how should I handle resources that are hold for a long time? Should I put `Control.Exception.finally` on every single line of my finalizers? What exceptions may occur on an IO operation? Every IO function has the risk of throwing an exception? Thanks, Thiago. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Handling exceptions or gracefully releasing resources
AFAIR, the only object that you need to be careful with is the Space [1], everything else is garbage collected. You could put the Space in a ResourceT, but only if it ran on its own thread (as soon as a block of ResourceT finishes, everything is deallocated, so you wouldn't be able to follow the approach taken by HipmunkPlayground). Cheers, [1] http://hackage.haskell.org/packages/archive/Hipmunk/5.2.0.10/doc/html/Physics-Hipmunk-Space.html#v:freeSpace On Wed, Jan 30, 2013 at 11:15 AM, Thiago Negri evoh...@gmail.com wrote: Felipe, I'm trying to use your Hipmunk package. :) The resources I need to keep around are the objects used for the simulation. Do you recomend using resourcet to handle this or something else? Thanks. 2013/1/30 Felipe Almeida Lessa felipe.le...@gmail.com Everything that Johan Tibell said + you may be interested in the resourcet package [1] (which is used by conduit to handle resources). Cheers, [1] http://hackage.haskell.org/package/resourcet On Tue, Jan 29, 2013 at 8:59 PM, Thiago Negri evoh...@gmail.com wrote: `Control.Exception.bracket` is a nice function to acquire and release a resource in a small context. But, how should I handle resources that are hold for a long time? Should I put `Control.Exception.finally` on every single line of my finalizers? What exceptions may occur on an IO operation? Every IO function has the risk of throwing an exception? Thanks, Thiago. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Felipe. -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Handling exceptions or gracefully releasing resources
`Control.Exception.bracket` is a nice function to acquire and release a resource in a small context. But, how should I handle resources that are hold for a long time? Should I put `Control.Exception.finally` on every single line of my finalizers? What exceptions may occur on an IO operation? Every IO function has the risk of throwing an exception? Thanks, Thiago. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Handling exceptions or gracefully releasing resources
Hi, The pattern is essentially the same as in imperative languages; every allocation should involve a finally clause that deallocates the resource. On Tue, Jan 29, 2013 at 2:59 PM, Thiago Negri evoh...@gmail.com wrote: Should I put `Control.Exception.finally` on every single line of my finalizers? I'm not sure what you're asking here. If your finally clause tries to call close, you don't have to catch exceptions raise by close (what would you do with them anyway). ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
