?roll-over ( x max -- x )

Vocabulary

snake-game.game

Inputs

x	an object
max	an object

Outputs

x

an object

Definition

USING: combinators kernel math ;

IN: snake-game.game

: ?roll-over ( x max -- x )
    {
        { [ 2dup >= ] [ 2drop 0 ] }
        { [ over neg? ] [ nip 1 - ] }
        [ drop ]
    } cond ;