ref? ( object -- ? )

Vocabulary

refs

Inputs and outputs

object	an object
?	a boolean

Word description

Tests if the object is an instance of the ref class.

Definition

USING: boxes classes.tuple.private kernel math.private
slots.private ;

IN: refs

: ref? ( object -- ? )
    dup tuple? [
        layout-of
        dup
        7
        slot
        dup
        \ box
        eq?
        [ drop t ]
        [
            dup \ slot-ref eq?
            [ drop t ] [
                dup \ global-var-ref eq?
                [ drop t ] [
                    dup \ var-ref eq?
                    [ drop t ] [ \ obj-ref eq? ] if
                ] if
            ] if
        ]
        if
        [ drop t ]
        [
            dup
            1
            slot
            9
            fixnum>=
            [
                9
                slot
                dup
                \ value-ref
                eq?
                [ drop t ]
                [ \ key-ref eq? ]
                if
            ]
            [ drop f ]
            if
        ]
        if
    ] [ drop f ] if ;