[IronPython] Error when using Options.FastEval

[Szymon Kobalczyk]

Hi,

Few days ago I wrote about a problem with Options.FastEval. I noticed 
today that accidentally it was posted as replay to some other topic and 
I'm not sure that anyone has seen it. So here it is again:

---

Last time I wrote here I was concerned with memory consumption and 
performance of embedding IronPython. I decided then to use the FastEval 
option.

I think I found some error in this mode. In code below the last line 
would throw "Key not found in dictionary." exception caused by the 
"None" term. When you don't use the FastEval the code runs properly.

       static void Main(string[] args)
       {
           IronPython.AST.Options.FastEval = true;
           IronPython.AST.Options.DoNotSaveBinaries = true;

           PythonEngine engine = new PythonEngine();

           engine.SetVariable("item", null);
           object value = engine.Evaluate("item == None");
       }

Also, could you please explain what exactly are the differences between 
the two modes.

Szymon Kobalczyk.

PS: Just found that it also doesn't work for the "str" builtin function 
but didn't have time to try others.