# Overriding CLS Virtuals **URL:** \ **Category:** IronRuby\ **Created:** [September 9, 2008, 6:22am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090 "2008-09-09T06:22:14Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 6:22am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/1 "2008-09-09T06:22:14Z")
I’ve committed some changes to IronRuby (in SVN revision 141) that let you implement CLS interfaces and override virtual methods on CLS base types. Interfaces work like Ruby modules, so to make your class implement IDisposable you could say require ‘mscorlib’ class Disposable include System.IDisposable def Dispose # Do something end end You can also override virtual properties. A class or interface that has the C# declaration “string Value { get; set; }” is overridden from IronRuby with methods named “Value” for the getter and “Value=” for the setter. Note that you need to use the same casing as the CLS definition for both methods and properties. We’re just getting started with better .NET interop support and don’t have very much test coverage yet - but this should let you get going on some more sophisticated interop scenarios than were previously possible. ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 6:23am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/2 "2008-09-09T06:23:59Z")
Oops… that should have said “include System::IDisposable”. My Outlook-based syntax checker is clearly not working. From: removed\_email\_address@domain.invalid [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Curt Hagenlocher Sent: Monday, September 08, 2008 9:22 PM To: removed\_email\_address@domain.invalid Subject: [Ironruby-core] Overriding CLS Virtuals I’ve committed some changes to IronRuby (in SVN revision 141) that let you implement CLS interfaces and override virtual methods on CLS base types. Interfaces work like Ruby modules, so to make your class implement IDisposable you could say require ‘mscorlib’ class Disposable include System.IDisposable def Dispose # Do something end end You can also override virtual properties. A class or interface that has the C# declaration “string Value { get; set; }” is overridden from IronRuby with methods named “Value” for the getter and “Value=” for the setter. Note that you need to use the same casing as the CLS definition for both methods and properties. We’re just getting started with better .NET interop support and don’t have very much test coverage yet - but this should let you get going on some more sophisticated interop scenarios than were previously possible. ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 6:37am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/3 "2008-09-09T06:37:26Z")
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**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 6:40am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/4 "2008-09-09T06:40:21Z")
It’s not real unless you start singing “You are the wind beneath my wings”. 🙂 On Mon, Sep 8, 2008 at 9:36 PM, Orion E. ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 7:13am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/5 "2008-09-09T07:13:06Z")
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**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 6:57am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/6 "2008-09-09T06:57:19Z")
* * * Ironruby-core mailing list removed\_email\_address@domain.invalid [http://rubyforge.org/mailman/listinfo/ironruby-core](http://rubyforge.org/mailman/listinfo/ironruby-core) ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 10:05am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/7 "2008-09-09T10:05:53Z")
Are we planning on supporting name mangling to give more Ruby-ish names? Like will we be able to do “def dispose” instead of “def Dispose”? JD * * * From: removed\_email\_address@domain.invalid [removed\_email\_address@domain.invalid] On Behalf Of Brad W. [removed\_email\_address@domain.invalid] Sent: Monday, September 08, 2008 9:39 PM To: removed\_email\_address@domain.invalid Subject: Re: [Ironruby-core] Overriding CLS Virtuals It’s not real unless you start singing “You are the wind beneath my wings”. 🙂 On Mon, Sep 8, 2008 at 9:36 PM, Orion E. \ wrote: You are my hero 🙂 Curt H. wrote: I’ve committed some changes to IronRuby (in SVN revision 141) that let you implement CLS interfaces and override virtual methods on CLS base types. Interfaces work like Ruby modules, so to make your class implement IDisposable you could say ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 1:26pm UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/8 "2008-09-09T13:26:48Z")
Yes, this has been reported before (in fact, I think it was when someone was writing “using” ☺) and we haven’t yet worked out a resolution. I’ll see if there’s something quick that can be fixed here later today. From: removed\_email\_address@domain.invalid [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Orion E. Sent: Monday, September 08, 2008 10:12 PM To: removed\_email\_address@domain.invalid Subject: Re: [Ironruby-core] Mysteriously broken calls to dispose? Follow-up If I call $fs.dispose(true), then it works. It seems there’s a protected dispose(bool) in a derived class. I can’t actually call Dispose(true) from C# as the compiler tells me it’s protected. It strikes me as somewhat broken that the method which ironruby actually invokes is the one that you shouldn’t invoke… At any rate, I’d be overjoyed if anyone could point me in the direction of a fix. I’m trying to write ‘using’ (a la C#) in ruby as part of demo for my local .NET user group. It should be trivial and showcase how awesome IronRuby is ☹ Orion E. wrote: I don’t seem to be able to call Dispose on a filestream. Needless to say this is problematic. Here’s a paste, straight from the IR console (latest svn version 141) > > > require ‘mscorlib’ =\> true > > > include System::IO =\> Object > > > $fs = FileStream.new( ‘file.txt’, FileMode.Open ) =\> #System::IO::FileStream:0x000005c > > > $fs.Dispose c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\matchcaller.generated.cs:30:in `Call2': wrong number or type of arguments for `Dispose’ (ArgumentError) ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\callsite.cs:275:in `UpdateAndExecute’ ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\updatedelegates.generated.cs:38:in `Update2’ ``` from :0 ``` > > > All the other methods on the filestream object work fine (read\_all\_text, and so on), but the call to dispose crashes. Likewise, I get a crash calling methods with overloads, which looks like it may (??) be related. > > > require ‘mscorlib’ =\> true > > > include System::IO =\> Object > > > $bytes = System::IO::File.read\_all\_bytes( ‘file.txt’ ); nil # nil is to prevent ir from printing the GIANT ARRAY =\> nil > > > $text = System::Text::Encoding.UTF8.get\_string($bytes) c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\matchcaller.generated.cs:35:in `Call3': wrong number or type of arguments for `get\_string’ (ArgumentError) ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\callsite.cs:275:in `UpdateAndExecute’ ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\updatedelegates.generated.cs:45:in `Update3’ ``` from :0 ``` > > > $text = System::Text::Encoding.UTF8.get\_string($bytes, 0, $bytes.length) =\> “PROPER TEXT GOES HERE” It seems like it can’t figure out that there is GetString(bytes) and GetString(bytes, index, length) and just uses the latter always. Is there a solution for either of these problems? Thanks a lot, Orion * * * * * * Ironruby-core mailing list removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [http://rubyforge.org/mailman/listinfo/ironruby-core](http://rubyforge.org/mailman/listinfo/ironruby-core) ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 1:34pm UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/9 "2008-09-09T13:34:59Z")
yep that is correct 🙂 [http://github.com/casualjim/ironnails/tree/master/IronNails/vendor/iron\_nails/lib/core\_ext/kernel.rb](http://github.com/casualjim/ironnails/tree/master/IronNails/vendor/iron_nails/lib/core_ext/kernel.rb) I figure you can wrap that in a begin…rescue block again and first try the one with the bool and then the one without it. Some implementations of Dispose don’t actually implement the method with a bool as parameter. Instead of FileStream you can use the ruby File class or you could write a FileStreamAdapter in C# or something so you can safely use it from IronRuby without the overloading mayhem. Cheers Ivan ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 1:40pm UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/10 "2008-09-09T13:40:16Z")
When you override a virtual method you’re pushing much more into CLR-world than when you’re just calling some function on some method. In the latter case, you shouldn’t have to know that the function you’re calling is actually defined outside of Ruby, while in the former, this is a fairly important piece of information. In any event, I recall that both John and Tomas felt that we shouldn’t – but no longer remember all the details. ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 5:55pm UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/11 "2008-09-09T17:55:22Z")
Let’s revisit that later, I’m also not sure what the details were. Tomas ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 9, 2008, 2:01pm UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/12 "2008-09-09T14:01:26Z")
Well, the interface itself only contains the parameterless method. The version with the parameter is part of a very common pattern that also optimizes the finalization experience and plays nicely with derived classes. If you’re really concerned about cleaning something up, you’ll probably follow that pattern. But if you’re just interested in the syntactic sugar of “using” and/or never expect the object’s lifespan to exceed that of the current method, then there’s no real need to implement the additional two methods or pay the cost of having a finalizer. (Even if you suppress it later, creating an object with a finalizer is more expensive than creating it without one iirc.) IDisposable is one of my favorite topics. I believe that officially makes me a masochist. From: removed\_email\_address@domain.invalid [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Ivan Porto Carrero Sent: Tuesday, September 09, 2008 4:34 AM To: removed\_email\_address@domain.invalid Subject: Re: [Ironruby-core] Mysteriously broken calls to dispose? yep that is correct 🙂 [http://github.com/casualjim/ironnails/tree/master/IronNails/vendor/iron\_nails/lib/core\_ext/kernel.rb](http://github.com/casualjim/ironnails/tree/master/IronNails/vendor/iron_nails/lib/core_ext/kernel.rb) I figure you can wrap that in a begin…rescue block again and first try the one with the bool and then the one without it. Some implementations of Dispose don’t actually implement the method with a bool as parameter. Instead of FileStream you can use the ruby File class or you could write a FileStreamAdapter in C# or something so you can safely use it from IronRuby without the overloading mayhem. Cheers Ivan On Tue, Sep 9, 2008 at 1:25 PM, Curt H. \ wrote: Yes, this has been reported before (in fact, I think it was when someone was writing “using” ☺) and we haven’t yet worked out a resolution. I’ll see if there’s something quick that can be fixed here later today. From: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Orion E. Sent: Monday, September 08, 2008 10:12 PM To: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Ironruby-core] Mysteriously broken calls to dispose? Follow-up If I call $fs.dispose(true), then it works. It seems there’s a protected dispose(bool) in a derived class. I can’t actually call Dispose(true) from C# as the compiler tells me it’s protected. It strikes me as somewhat broken that the method which ironruby actually invokes is the one that you shouldn’t invoke… At any rate, I’d be overjoyed if anyone could point me in the direction of a fix. I’m trying to write ‘using’ (a la C#) in ruby as part of demo for my local .NET user group. It should be trivial and showcase how awesome IronRuby is ☹ Orion E. wrote: I don’t seem to be able to call Dispose on a filestream. Needless to say this is problematic. Here’s a paste, straight from the IR console (latest svn version 141) > > > require ‘mscorlib’ =\> true > > > include System::IO =\> Object > > > $fs = FileStream.new( ‘file.txt’, FileMode.Open ) =\> #System::IO::FileStream:0x000005c > > > $fs.Dispose c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\matchcaller.generated.cs:30:in `Call2': wrong number or type of arguments for `Dispose’ (ArgumentError) ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\callsite.cs:275:in `UpdateAndExecute’ ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\updatedelegates.generated.cs:38:in `Update2’ ``` from :0 ``` > > > All the other methods on the filestream object work fine (read\_all\_text, and so on), but the call to dispose crashes. Likewise, I get a crash calling methods with overloads, which looks like it may (??) be related. > > > require ‘mscorlib’ =\> true > > > include System::IO =\> Object > > > $bytes = System::IO::File.read\_all\_bytes( ‘file.txt’ ); nil # nil is to prevent ir from printing the GIANT ARRAY =\> nil > > > $text = System::Text::Encoding.UTF8.get\_string($bytes) c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\matchcaller.generated.cs:35:in `Call3': wrong number or type of arguments for `get\_string’ (ArgumentError) ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\callsite.cs:275:in `UpdateAndExecute’ ``` from ``` c:\development\ironruby\trunk\src\microsoft.scripting.core\actions\updatedelegates.generated.cs:45:in `Update3’ ``` from :0 ``` > > > $text = System::Text::Encoding.UTF8.get\_string($bytes, 0, $bytes.length) =\> “PROPER TEXT GOES HERE” It seems like it can’t figure out that there is GetString(bytes) and GetString(bytes, index, length) and just uses the latter always. Is there a solution for either of these problems? Thanks a lot, Orion * * * * * * Ironruby-core mailing list removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [http://rubyforge.org/mailman/listinfo/ironruby-core](http://rubyforge.org/mailman/listinfo/ironruby-core) * * * Ironruby-core mailing list removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [http://rubyforge.org/mailman/listinfo/ironruby-core](http://rubyforge.org/mailman/listinfo/ironruby-core) ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 10, 2008, 11:46pm UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/13 "2008-09-10T23:46:23Z")
Are we going to have “real” properties under the hood, because what we have for now is just method with “get\_PropertyName”? And this did not play nicely with databinding. I think the same question applies for events as well. 2008/9/9 Curt H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![curthibbs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/ac91a4/32.png) [@curthibbs](https://www.ruby-forum.com/u/curthibbs)\ **Post date:** [September 17, 2008, 1:15am UTC](https://www.ruby-forum.com/t/overriding-cls-virtuals/148090/14 "2008-09-17T01:15:21Z")
Right now, the only way to get properties is to implement an interface that defines them. When IronRuby supports this “natively”, it will have to define a syntax for doing so. That’s because the Ruby language supports neither properties, attributes nor static types - all of which will be needed. This will probably involve adding some new methods to Class that allow you to define typed CLS members. But we don’t have a specific timeframe for implementing this yet. From: removed\_email\_address@domain.invalid [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Stefan D. Sent: Wednesday, September 10, 2008 2:46 PM To: removed\_email\_address@domain.invalid Subject: Re: [Ironruby-core] Overriding CLS Virtuals Are we going to have “real” properties under the hood, because what we have for now is just method with “get\_PropertyName”? And this did not play nicely with databinding. I think the same question applies for events as well. 2008/9/9 Curt H. \ I’ve committed some changes to IronRuby (in SVN revision 141) that let you implement CLS interfaces and override virtual methods on CLS base types. Interfaces work like Ruby modules, so to make your class implement IDisposable you could say require ‘mscorlib’ class Disposable include System.IDisposable def Dispose ``` # Do something ``` end end You can also override virtual properties. A class or interface that has the C# declaration “string Value { get; set; }” is overridden from IronRuby with methods named “Value” for the getter and “Value=” for the setter. Note that you need to use the same casing as the CLS definition for both methods and properties. We’re just getting started with better .NET interop support and don’t have very much test coverage yet - but this should let you get going on some more sophisticated interop scenarios than were previously possible. – Curt H. removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)