Does mono 2.8 support 'dynamic' keyword? - dynamic

Question

I tested IronPython on mono 2.8 with the code in the book Professional IronPython p.315 listing 15-3.
using System;
using IronPython.Hosting;
using IronPython.Runtime;
using Microsoft.Scripting.Hosting;
namespace Method2
{
class Program
{
static void Main(string[] args)
{
// Obtain the runtime.
var IPY = Python.CreateRuntime();
// Create a dynamic object containing the script.
dynamic TestPy = IPY.UseFile("TestClass.py");
// Execute the __test__() method.
TestPy.__test__();
}
}
}
I see it's compiled OK, and run without a problem on Windows 7, whereas the mono 2.8 gives me the following error message.
Unhandled Exception: Microsoft.CSharp.RuntimeBinder.RuntimeBinderException:
`Microsoft.Scripting.Hosting.ScriptScope' does not contain a definition for `__test__'
at (wrapper dynamic-method) object.CallSite.Target (System.Runtime.CompilerServices.Closure,System.Runtime.CompilerServices.CallSite,object)
at System.Dynamic.UpdateDelegates.UpdateAndExecuteVoid1
(System.Runtime.CompilerServices.CallSite,object)
at Method2.Program.Main (string[])
I thought Mono 2.8 supports C# 4.0 which has the dynamic keyword, but I see that the 'dynamic' keyword is not fully supported with mono.
Is this a bug of Mono 2.8?
ADDED
This is the python script.
# The class you want to access externally.
class DoCalculations():
# A method within the class that adds two numbers.
def DoAdd(self, First, Second):
# Provide a result.
return First + Second
# A test suite in IronPython.
def __test__():
# Create the object.
MyCalc = DoCalculations()
# Perform the test.
print MyCalc.DoAdd(5, 10)
# Pause after the test session.
raw_input('\nPress any key to continue...')
This is the command that I used
dmcs Program.cs /r:System.Core /r:IronPython.dll /r:IronPython.Modules.dll /r:Microsoft.Dynamic.dll /r:Microsoft.Scripting.dll /r:Microsoft.CSharp.dll
It compiles well, but it still breaks when I run the execution binary. Do I need to have all the dlls in the same directory where the execution binary locates?

Answer 1

The fact that you are getting a Microsoft.CSharp.RuntimeBinder.RuntimeBinderException means that the dynamic keyword worked. The problem you are having is that IPY.UseFile("TestClass.py"); is returning a ScriptScope that doesn't see your test method. So the problem lies with your python source or how you are including IronPython with mono.

Answer 2

The dynamic keyword is certainly supported by Mono 2.8 when using the C# 4 profile.
I guess my question is how you are building this sample?
Just for kicks, I just pasted your sample into MonoDevelop. I had to tell MonoDevelop to use C# 4 instead of C# 3.5 first of all.
The dynamic keyword was introduced in C# 4 obviously.
Also, I did have to include a few assembly references: System.Core, IronPython.dll, IronPython.Modules.dll, Microsoft.Dynamic.dll, Microsoft.Scripting.dll, and Microsoft.CSharp.dll. I am not sure if I needed them all.
If you are building from the command-line you need to use 'dmcs' as the compiler (to indicate the .NET 4 profile) and you need to include the assembly references.
It builds without problems with this configuration (for me at least).

Answer 3

I am responding to this question with respect to Mono 2.10.
I could successfully build and execute the code from command line on Windows 7 without using MonoDevelop. Here are the steps:
Install Mono 2.10.8 on Windows 7.
Install IronPython 2.7.2.1.
"C:\Program Files\Mono\bin" or equivalent and "C:\Program Files\IronPython 2.7" or equivalent should be part of system path.
Both TestClass.py and Program.cs should be in the same folder.
From the dos prompt, corresponding to the folder where TestClass.py and Program.cs exists, execute setmonopath batch file.
From the same dos prompt execute the following command:
dmcs Program.cs /r:System /r:"C:\Program Files\IronPython 2.7\IronPython.dll" /r:"C:\Program Files\IronPython 2.7\IronPython.Modules.dll" /r:"C:\Program Files\IronPython 2.7\Microsoft.Dynamic.dll" /r:"C:\Program Files\IronPython 2.7\Microsoft.Scripting.dll" /r:"C:\program Files\IronPython 2.7\Microsoft.Scripting.MetaData.dll" /r:Microsoft.Csharp
Program.exe should be successfully generated and the same can be executed without any error message.