spork/misc/dfs

    function
    /usr/local/lib/janet/spork/misc.janet on line 164, column 1

    (dfs data visit-leaf &opt node-before node-after get-children seen)

    Do a depth first, pre-order traversal over a data structure. Also 
    allow for callbacks before and after visiting the children of a 
    node. Also allow for a custom `get-children` function to change 
    traversal as needed. Will detect cycles if an empty table is passed 
    as the `seen` parameter, which is used to cache values that have 
    been visited.