Fun with Lambda.Compile: Code? Data?

Another very funky twist of C# 3.0 new features: in the following code snippet, tell what’s code (I.E. MSIL), what’s data (I.E. expression tree) and when the “data” gets compiled into “code”. (By the way, Today happens to be May 3^rd, 2007).

Expression<Func<int,

    Expression<Func<int, int>>>> expr1

        = (a => (b => a + b * 3));

 

Expression<Func<int, int>> expr2 =

    expr1.Compile().Invoke(DateTime.Today.Day);

 

Func<int, int> func = expr2.Compile();

Console.WriteLine(func(10));

In case you have no clue, look into the structure of expr1 and expr2 might help:

No wonder LambdaExpression.Compile is Don Box’s favorite in C# 3.0.

Having fun…