For the devil’s advocate position Ivan was arguing for, you could argue that IronRuby should only allow *adding* new members to CLR types, not to edit or delete existing CLR members. The added members would be visible only from Ruby. From C#, you will get compiler errors anyway if you try to call these added members (unless you use “dynamic” in C# 4.0), and so having two different views of the CLR type is OK here since there is no scope for confusion.
This would be somewhat similar to the way C# extension methods work – the real methods of the type get precedence, and extension methods (comparable to monkey-patched Ruby methods) get lower precedence during overload resolution. Building a special mocking framework for IronRuby does not change the basic fact that CLR types are unmodifiable. A special framework will work only if the app is all IronRuby code, but it will break when C# is thrown in the mix. The current plan is to allow monkey-patching of CLR members on CLR types. It does give power but has some unpredictability as well. Feedback and real-world experience is welcome about whether this is the right thing or not. From: [email protected] [mailto:[email protected]] On Behalf Of Jimmy Schementi Sent: Wednesday, May 13, 2009 10:03 AM To: [email protected] Subject: Re: [Ironruby-core] more interop questions I want to re-emphasize and expand a bit on what Tomas said: monkey-patching .NET will only be visible from Ruby. You could look at this as a feature of IronRuby as it will never break .NET code. In reality, it’s a limitation of the CLR which does not allow modification of types once they are created. Ivan, this is exactly why a special mocking framework needs to be built for IronRuby =) To make this a bit more concrete, here’s a simple example: class Foo { public int Bar() { return 42; } public void SayBar() { System.Console.WriteLine(Bar()); } } The SayBar() method is compiled to call the method Bar(). When this Ruby code is executed: class Foo def Bar “Monkey patched!” end end The .NET “Foo” class is not changed, but a new type is created and the Ruby method resolution knows to check this Ruby class first, then the “Foo” .NET type (I’m drastically overly-simplifying the way method lookup works, but for this example it’ll do =P). So when Bar() is called from Ruby it will give you the Ruby method: >>> Foo.new.Bar => “Monkey Patched!” But the SayBar() method will always call the static version of Bar(), because monkey-patching has no effect on the .NET view of the world. >>> Foo.new.SayBar 42 => nil The only way to truly modify the “.NET-view” from Ruby is via System.Reflection. Today C# code can only call into DLR code by using the DLR Hosting API, though as Tomas mentioned that is improving in C#4. I’ll add this to the wiki, as I’m beginning to build up our .NET integration documentation … keep asking questions like this to make my life easier =) ~Jimmy From: [email protected] [mailto:[email protected]] On Behalf Of Tomas Matousek Sent: Wednesday, May 13, 2009 9:37 AM To: [email protected] Subject: Re: [Ironruby-core] more interop questions It’s pretty simple: your can define a Ruby method on any class/interface. The method will only be visible from Ruby unless the class is a Ruby dynamic object (implements IDynamicObjectProvider using Ruby binders). For such dynamic objects Ruby methods will be available when invoked from dynamic expression in C# 4.0. The methods are also invokable via ObjectOperations class in Hosting API. Tomas From: [email protected] [mailto:[email protected]] On Behalf Of Ivan Porto Carrero Sent: Wednesday, May 13, 2009 9:20 AM To: ironruby-core Subject: Re: [Ironruby-core] more interop questions I know these sound like pretty basic questions.. but I'm playing devil's advocate here (maybe rubyist advocate is better suited) and I imagine I will need a good chunk in a chapter somewhere to explain this stuff really clearly. --- Met vriendelijke groeten - Best regards - Salutations Ivan Porto Carrero Blog: http://flanders.co.nz Twitter: http://twitter.com/casualjim Author of IronRuby in Action (http://manning.com/carrero) On Wed, May 13, 2009 at 5:57 PM, Ivan Porto Carrero <[email protected]<mailto:[email protected]>> wrote: Hi I got into a discussion with Roy Osherhove about overriding statics. I know in C# it can't be done obviously and as long as I stay in Ruby you can. I understand this may seem like straight-forward stuff. Can you give me a pointer where I can take stock of what I can and can't do to CLR objects and in which cases ruby things apply? But when you go back and call it from a C# class it takes the CLR implementation public class MyClassWithAStatic{ public string HelloWorld(){ return "Hello World!"; } public static string GoodByeWorld(){ return "Goodbye world!"; } } public class StaticCaller{ public string CallsStatic(){ return MyClassWithAStatic.GoodByeWorld(); } } console session: (master) » ir IronRuby 0.4.0.0 on .NET 2.0.50727.4918 Copyright (c) Microsoft Corporation. All rights reserved. >>> require 'spec/bin/ClrModels.dll' => true >>> include ClrModels => Object >>> MyClassWithAStatic => ClrModels::MyClassWithAStatic >>> MyClassWithAStatic.good_bye_world => 'Goodbye world!' >>> sc = StaticCaller.new => ClrModels.StaticCaller >>> sc.calls_static => 'Goodbye world!' >>> class MyClassWithAStatic ... def self.good_bye_world ... "From Ruby we say goodbye to you" ... end ... end => nil >>> MyClassWithAStatic.good_bye_world => "From Ruby we say goodbye to you" >>> sc = StaticCaller.new => ClrModels.StaticCaller >>> sc.calls_static => 'Goodbye world!' New session to figure out if something could be done before the type was actually created + C:\dev\caricature (master) » ir IronRuby 0.4.0.0 on .NET 2.0.50727.4918 Copyright (c) Microsoft Corporation. All rights reserved. >>> require 'spec/bin/ClrModels.dll' => true >>> class MyClassWithAStatic ... def self.good_bye_world ... "From Ruby we say goodbye to you" ... end ... end => nil >>> ClrModels::StaticCaller.new.calls_static => 'Goodbye world!' --- Met vriendelijke groeten - Best regards - Salutations Ivan Porto Carrero Blog: http://flanders.co.nz Twitter: http://twitter.com/casualjim Author of IronRuby in Action (http://manning.com/carrero) Don Marquis<http://www.brainyquote.com/quotes/authors/d/don_marquis.html> - "Procrastination is the art of keeping up with yesterday."
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