Rebol [
    Title: "Cfor"
    File: %cfor.r
    Author: "Ladislav Mecir"
    Date: 27-Jun-2005/8:22:28+2:00
    History: [
        13/Dec/2002/8:30 {using INC block}
        27-Jun-2005/8:22:28+2:00 {using #include}
    ]
    Purpose: {General loop for REBOL}
]

#include %set-words.r

comment [
    Example:

    ; Instead of incrementing the cycle variable you can e.g. double it
    ; much faster than the R2 Core FOR
    cfor [num: 0] [num <= 30] [num: num + 1] [
        if num = 15 [recycle]
        print num
    ]
    cfor [i: 1] [i <= 2000] [i: i + i] [print i]
]

cfor: func [
    {General loop}
    [throw]
    init [block!]
    test [block!]
    inc [block!]
    body [block!]
] [
    use set-words init reduce [
        :do init
        :while test head insert tail copy body inc
    ]
]