REBOL 3 Concepts: Functions: Unnamed Functions

Pending Revision

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

Function names are variables. In REBOL, a variable is a variable, regardless of what it holds. There is nothing special about function variables.

Furthermore, functions do not require names. You can create a function and immediately evaluate it, store it in a block, pass it as an argument to a function, or return it as a result from a function. Such functions are unnamed.

Here is an example that creates a block of unnamed functions:

funcs: []
repeat n 10 [
    append funcs func [t] compose [t + (n * 100)]
]
print funcs/1 10
110

print funcs/5 10
510

Functions can also be created and passed to other functions. For instance, when you use sort with your own comparison, you provide a function as an argument:

sort/compare data func [a b] [a > b]