REBOL 3 Concepts: Functions

Pending Revision

This document was written for R2 and has yet to be revised for R3.

Types

There are several kinds of functions provided by REBOL:

Native	A function that is evaluated directly by the processor. These are the lowest level functions of the language.
Function	A higher level function that is defined by a block and is evaluated by evaluating the functions within the block. Also called user-defined functions.
Mezzanine	A name for higher level functions that are a standard part of the language. These are not native functions.
Operator	A function that is used as an infix operator. Examples are +, -, [bad-link:functions/z-gtb-lt.txt] and /.
Routine	A function that is used to call external library functions (REBOL/Command feature).