[datatypes] action! vs. native! vs function!

Hi, all, OK, so a FUNCTION! is a function written in REBOL itself (what FORTH used to call "high-level" in contrast with "primitive"). I've always thought of NATIVE! as "primitive" in the above contrast -- a function written inside the interpreter in C (or whatever), but then ACTION! enters the picture and leaves me scratching my head. Does anyone know the difference between NATIVE! and ACTION! types? -jn-

Hi Joel, On Saturday, November 22, 2003, 11:15:09 PM, you wrote: JN> Does anyone know the difference between NATIVE! and ACTION! JN> types? The list of the types in the ANY-FUNCTION! pseudo-type is: native! action! op! function! As you say, FUNCTION! values are the one we can create. ACTION!, OP! and NATIVE! values are "built in" in the interpreter, and we cannot create them. The distinction between the three is a little subtle, and is mainly an implementation issue I think (IIRC, Carl once said this, too). NATIVE!s are the "primitives", as you say. ACTION!s are those primitives that are actually "methods" (to use terminology from other languages) in other datatypes; that is, while for a NATIVE! there is one C implementation inside REBOL, for an ACTION! there can be more than one implementation; for example, PICK on a PORT! is different from PICK on a BLOCK!. While doing what you call "particle physics", I and others also discovered this:

>> second :print

>> second :pick