Ah I see. I've started implementing a Lisp interpreter in C# and I also was going along the path of making everything "first class" by using f-expressions wher

Ah I see. I've started implementing a Lisp interpreter in C# and I also was going along the path of making everything "first class" by using f-expressions where appropriate. So far my only actual f-expressions are "lambda" and "if" - everything else is bootstrapped as macros or functions. My "apply" currently expects a function but I was toying with making it "eval" the cons macro... but then "apply" has to become an f-expression instead of just a plain normal function which seemed inelegant so I left it as a function that requires a function. Reading your story... I think I'll leave it permanently side-stepped!! :-)