[Ironruby-core] Calling a C# method with a byref parameter

Shri Borde Shri.Borde at microsoft.com
Fri Feb 12 15:20:49 EST 2010


About documentation, the bottom of http://ironpython.net/documentation/dotnet/ has this placeholder :(

    Appendix - Rules for Type parameter inference while invoking generic methods
    TODO

Jim, Dino had added tests for IronPython, and you should be able to leverage those for IronRuby

http://ironruby.codeplex.com/WorkItem/View.aspx?WorkItemId=3395  also tracks the issues with generic inference.

________________________________
From: ironruby-core-bounces at rubyforge.org [ironruby-core-bounces at rubyforge.org] on behalf of Jim Deville [jdeville at microsoft.com]
Sent: Friday, February 12, 2010 9:06 AM
To: ironruby-core at rubyforge.org
Subject: Re: [Ironruby-core] Calling a C# method with a byref parameter

Generic type inference should work like it does in C#. I’ll get some more tests in there and get Jimmy to update the docs.

JD

From: ironruby-core-bounces at rubyforge.org [mailto:ironruby-core-bounces at rubyforge.org] On Behalf Of Ryan Riley
Sent: Thursday, February 11, 2010 9:56 AM
To: ironruby-core at rubyforge.org
Subject: Re: [Ironruby-core] Calling a C# method with a byref parameter

On what types will IR be able to infer the types? Is that documented on the site and I just didn't see it?

Ryan Riley

On Thu, Feb 11, 2010 at 9:55 AM, Jim Deville <jdeville at microsoft.com<mailto:jdeville at microsoft.com>> wrote:
That call actually should (usually) be able to infer the type. Please file a bug on codeplex that Generic Type inference isn’t working with ByRef types.

JD

From: ironruby-core-bounces at rubyforge.org<mailto:ironruby-core-bounces at rubyforge.org> [mailto:ironruby-core-bounces at rubyforge.org<mailto:ironruby-core-bounces at rubyforge.org>] On Behalf Of Shay Friedman
Sent: Thursday, February 11, 2010 6:53 AM
To: ironruby-core at rubyforge.org<mailto:ironruby-core at rubyforge.org>
Subject: Re: [Ironruby-core] Calling a C# method with a byref parameter

You should call generic methods a bit differently.

The next code works:
ret_val = c.method(:do_something_else).of(String).call(str)

Shay.
--------------------------------------------------------
Shay Friedman | .NET Technologies Expert | Author of IronRuby Unleashed | Sela Technology Center
Blog: http://IronShay.com | Twitter: http://twitter.com/ironshay
On Thu, Feb 11, 2010 at 4:44 PM, Michael Erasmus <michaelerasmus at gmail.com<mailto:michaelerasmus at gmail.com>> wrote:
Thanks Shay.

OK your code works. But my trouble seems to come in with the Generic method.

When I do:

public class Class1
    {
        public string DoSomething(ref string test)
        {
            test = test + "tamtamtam";

            return "return value";
        }

        public string DoSomethingElse<T>(ref T test)
        {
            return test.ToString();
        }
    }

and then call it from IR:


>>> c = TestClass::Class1.new
=> TestClass.Class1
>>> c.do_something("Bla")
=> ['return value', 'Blatamtamtam']
>>> c.do_something_else("Bla")
Microsoft.Scripting.Core:0:in `Bind': Expression of type 'IronRuby.Builtins.Muta
bleString&' cannot be used for parameter of type 'IronRuby.Builtins.MutableStrin
g' of method 'System.String DoSomethingElse[MutableString](IronRuby.Builtins.Mut
ableString ByRef)' (ArgumentError)
        from Microsoft.Scripting.Core:0:in `BindCore'
        from :0




On Thu, Feb 11, 2010 at 4:12 PM, Shay Friedman <shay.friedman at gmail.com<mailto:shay.friedman at gmail.com>> wrote:
It returns another return value with the new ref value.

For example, if you have the next c# class:
public class Class1
{
    public string DoSomething(ref string test)
    {
        test = test + "tamtamtam";

        return "return value";
    }
}

This is the IronRuby code you can write to use it:
>>> require 'c:\dev\TestApps\TestClass\TestClass\bin\Debug\TestClass.dll'
=> true
>>> c = Class1.new
=> TestClass.Class1
>>> str = "hello"
=> "hello"
>>> result = c.do_something(str)
=> ['return value', 'hellotamtamtam']

Pay attention that the result variable is an array that contains the method return value as the first item and the ref value as the second parameter.

Shay.
--------------------------------------------------------
Shay Friedman | .NET Technologies Expert | Author of IronRuby Unleashed | Sela Technology Center
Blog: http://IronShay.com | Twitter: http://twitter.com/ironshay
On Thu, Feb 11, 2010 at 3:44 PM, Michael Erasmus <michaelerasmus at gmail.com<mailto:michaelerasmus at gmail.com>> wrote:
Hi Everyone,

I'm trying to write a IronRuby script that interops with a a .NET assembly written in C#.

It has a class that derives from a base class in the .NET assembly. One of the base class protected methods looks like this:

protected void OnNotifyPropertyChanged<T>(string name, ref T localmember, T value)
 {
         ......
 }

I can't for the life of me figure out how to call this method from IR in my derived class.
The documentation mentions that you can call out parameters without using them as arguments, but I can't seem to find anything about ref params.

If I just try calling the method like this:

OnNotifyPropertyChanged(property_name, value, value)

I get this error:

Microsoft.Scripting.Core:0:in `Bind': Expression of type 'IronRuby.Builtins.Muta
bleString&' cannot be used for parameter of type 'IronRuby.Builtins.MutableStrin
g' of method 'Void #base#OnNotifyPropertyChanged[MutableString](System.String, I
ronRuby.Builtins.MutableString ByRef, IronRuby.Builtins.MutableString)' (Argumen
tError)
        from Microsoft.Scripting.Core:0:in `BindCore'
        from ./dynamic_event_item.rb:22:in `method_missing'
        from :0


Am I missing something?

Thanks

Michael Erasmus


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