I know nothing about LUA syntax, so I also have no idea which part of this is new and which part is ordinary LUA.
Is -- calculate sum(x for x^2 in 1..n) a comment or is it the output of a code transform?
Is -- calculate sum(x for x^2 in 1..n) a comment or is it the output of a code transform?
The point is not about expressiveness; it's that while this code composes several higher-order functions, it's compiled into the kind of assembly code you'd expect from a fully optimized C routine.