pick-balances ( a node -- balance balance )

Vocabulary

trees.avl.private

Inputs

a	an object
node	an object

Outputs

balance	an object
balance	an object

Definition

USING: accessors combinators kernel math ;

IN: trees.avl.private

: pick-balances ( a node -- balance balance )
    balance>> {
        { [ dup zero? ] [ 2drop 0 0 ] }
        { [ 2dup = ] [ nip neg 0 ] }
        [ drop 0 swap ]
    } cond ;