(levelorder) ( dlist quot: ( data -- ) -- )

Vocabulary

rosetta-code.tree-traversal

Inputs

dlist	an object
quot	a quotation with stack effect ( data -- )

Outputs

None

Definition

USING: accessors combinators deques kernel ;

IN: rosetta-code.tree-traversal

: (levelorder) ( dlist quot: ( data -- ) -- )
    over deque-empty?
    [ 2drop ] [
        [ dup pop-front ] dip {
            [ [ data>> ] dip call drop ]
            [ drop left>> [ swap push-back ] [ drop ] if* ]
            [ drop right>> [ swap push-back ] [ drop ] if* ]
            [ nip (levelorder) ]
        } 3cleave
    ] if ; inline recursive