SET+ (See related posts)

    set+: func [ ; Inspired by Erlang's list model.
        "Like SET, but words block is dialected."
        words  [any-block!] "Word after | gets remainder of series."
        series [series!]
        /local word= rule=
    ][
        word=: [set word word!]
        rule=: [
            any [
                '| word= (set word series) to end
                | word= (
                    set word pick series 1
                    series: next series
                )
            ]
        ]
        parse words rule=
    ]
    ;set+ [a | rest] [1 2 3 4 5]
    ;set+ [a b | rest] [1 2 3 4 5]
    ;set+ [a b c] [1 2]