move-backward-of ( seq shift from to -- seq )

Vocabulary

sequences.extras.private

Inputs

seq	an object
shift	an object
from	an object
to	an object

Outputs

seq

an object

Definition

USING: kernel math ;

IN: sequences.extras.private

: move-backward-of ( seq shift from to -- seq )
    2dup =
    [ 3drop ] [
        [ [ [ + ] keep move-unsafe-of ] 2keep 1 + ] dip
        move-backward-of
    ] if ;