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[Caml-list] Resource acquisition is initialization
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| Date: | -- (:) |
| From: | Blair Zajac <blair@o...> |
| Subject: | Re: [Caml-list] Resource acquisition is initialization |
Xavier Leroy wrote: > > > One of the nice things about C++ and Java is that with properly > > designed classes, you don't need to worry about freeing resources > > in complicated code, because the when the objects go out of scope > > either normally or via an exception, they will clean themselves up. > > I believe this is a C++-specific idiom. Java doesn't have > destructors, just finalizers that are called asynchronously by the > GC. OCaml also has GC finalization (see below). > > > Given that Ocaml has objects, it would be useful to have this > > idiom available to us. Is there a way to implement it, rather > > than just waiting for the garbage collector? > > Yes: higher-order functions. For a file: > > let with_file_in filename action = > let ic = open_in filename in > try > let res = action ic in close_in ic; res > with x -> > close_in ic; raise x > > For a mutex: > > let synchronize mut action = > try > Mutex.lock mut; > let res = action () in > Mutex.unlock mut; > res > with x -> > Mutex.unlock mut; > raise x > > You get the idea. Thanks for all the answers everybody sent, both on and off list, it's much appreciated. Best, Blair -- Blair Zajac <blair@orcaware.com> Plots of your system's performance - http://www.orcaware.com/orca/ ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners