Rebol [
    Title: "Tuntil"
    File: %tuntil.r
    Date: 23-Aug-2005/10:32:41+2:00
    Author: "Ladislav Mecir"
]

#include-check %tfunc.r

tuntil: tfunc [
    {a transparent until}
    block [block!]
    /local result1 result2
] [
    block: bind/copy block use [break] [
        break: func [[throw] /return value [any-type!]] [
            either return [return' get/any 'value] [exit]
        ]
        'break
    ]
    result1: false
    error? set/any 'result2 until [
        set/any 'result1 do block
        if not value? 'result1 [
            throw' make error! [script no-return]
        ]
        :result1
    ]
    either :result1 [:result2] [
        break/return get/any 'result2
    ]
]

comment [
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