> It seems trivial to do in any language where functions are first class citizens When you put that in the historical context, you will see that first class fu

> It seems trivial to do in any language where functions are first class citizens When you put that in the historical context, you will see that first class function with dynamic scoping are coming around that time. Also, Scheme which was the LISP used in the story, was the first introducing proper support for lexically scoped first-class functions. I would guess that Javascript inherited this from Scheme.