I am trying to get dynamic expresso to interpret this line of code:

(((IDictionary<string, object>)o)["Diesel % in oil"].ToString().StartsWith("<") ? ((IDictionary<string, object>)o)["Diesel % in oil"].ToString().Replace("<", String.Empty) : ((IDictionary<string, object>)o)["Diesel % in oil"].ToString())

When it executes I get the following exception Unknown identifier 'IDictionary' (at index 3).

I am testing for a "<" at the start and then replacing all instances of the "<" (excuse the terrible key name - out of my control that one!).

I have tried adding typeof(System.Collections.Generic.IDictionary<string, object>) as a reference to the interpreter object, but no joy.

The full code:

    var interpreter = new Interpreter();
    interpreter.Reference(typeof(System.Collections.Generic.IDictionary<string, object>));
    interpreter.SetVariable("o", o);
    return (T)interpreter.Eval(code);

I'm sure I'm missing something simple.