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Disposable objects in classes
f#classes

Hi,

When coding a class, is there a way to delete the disposable objects at the same time ? The "use" keywords not being allowed with implicit constructors.

Thanks a lot.

Julien

.

Maybe you should implement IDisposable and override Finalize() ?

By on 8/6/2008 12:24 PM ()

Hi,

perhaps Julian is referring to disposal of the member objects of a class instance?

attempting to use implicit class constructors with use bindings causes the following error:

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type ParentClass() =

    use child = new ChildClass()

Warning FS0191: 'use' bindings are not permitted in implicit class constructors. file1.fs

using a let binding, however, doesn't call the Dispose function in child objects.

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#light

module DisposalTest 

open System

type ChildClass() =
    do printfn "creating object of class ChildClass"
    interface IDisposable with
        member x.Dispose() = printfn "disposed object of class ChildClass"

type ParentClass() =
    let child = new ChildClass()
    do printfn "creating object of class ParentClass"
    interface IDisposable with
        member x.Dispose() = printfn "disposed object of class ParentClass"
        
let main() =
    use parent = new ParentClass()
    ()
    
do main()

produces the following output

>project1.exe
creating object of class ChildClass
creating object of class ParentClass
disposed object of class ParentClass

notice that ChildClass.Dispose() is not called.

warm regards,

Danny

By on 8/6/2008 2:30 PM ()

You should override Dispose instead of reintroducing it's implementation. Or excplicitly call base's dispose.

By on 8/6/2008 10:26 PM ()

I was indeed wondering about the use of the "use" keyword in implicit constructions as mentioned by Danny Asher.

The reason was that I saw the issue in the control.fs file of the distribution in the the mailbox class, and was wondering if there was a way to avoid implementing the IDisposable interface...

Thanks for your help !

By on 8/7/2008 5:10 AM ()

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