To this list, I would add code quotations. You can <@...@> around any expression and get a syntax tree at runtime that you can explore, transform and even compi

To this list, I would add code quotations. You can <@...@> around any expression and get a syntax tree at runtime that you can explore, transform and even compile. While C# does have a similar feature in Linq.Expressions there are entire categories of (completely banal) C# expressions that cannot be quoted.