REBOL [
    title: "collect"
    file: %collect.r
    author: "Brett Handley"
    email: brett@codeconscious.com
    web: http://www.codeconscious.com
    date: 24-Jul-2003
    purpose: "Accumulate a repeated expression.."
]

collect: func [
    {Collects block evaluations, use as body in For, Repeat, etc.}
    block [block!] "Block to evaluate."
    /initial result [series! datatype!] "Initialise the result."
    /only "Inserts into result using Only refinement."
] [
    if not initial [result: block!]
    result: any [all [datatype? result make result 1000] result]
    reduce ['head pick [insert insert/only] not only 'tail result to paren! block]
]

comment [
    for i 1 10 2 collect [i * 10]
    foreach [a b] [1 2 3 4] collect [a + b]
    foreach w [a b c d] collect [w]
    repeat e [a b c %.txt] collect/initial [e] %file
    iota: func [n [integer!]][repeat i n collect/initial [i] make block! n]
    iota 10
]