[REBOL] Re: skip a value inside 'foreach

From: lmecir:mbox:vol:cz at: 16-Nov-2002 16:33

Hi Halvard,

you can use e.g.

    cfor [i: 1] [i <= 3] [i: i + 1] [
        if i = 2 [continue]
        print i
    ]

-L

The CFOR function is (much) faster, than FOR and here is its implementation:

    set-words: function [
        {Get all set-words from a block}
        block [block!]
    ] [elem words] [
        words: make block! length? block
        parse block [
            any [
                set elem set-word! (
                    insert tail words to word! :elem
                ) | skip
            ]
        ]
        words
    ]

    cfor: function [
        {a C-like for function}
        [throw]
        init [block!]
        test [block!]
        inc [block!]
        body [block!]
    ] [use-words cont] [
        use-words: append set-words init [continue]
        body: append reduce [:catch body] inc
        cont: reduce [does [throw none]]
        use use-words reduce [
            :set [continue] cont
            :do init
            :while test body
        ]
    ]

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