use "bb_search.sml";

fun bbOdoIncr4 []      = NONE
  | bbOdoIncr4 (x::xs) =
    if x < 4 then
        SOME ((x+1)::xs)
    else
        bbOdoIncr4 xs;

fun bbOdoIncr _   []      = NONE
  | bbOdoIncr top (x::xs) =
    if x < top then
        SOME ((x+1)::xs)
    else
        bbOdoIncr top xs;

fun bbOdoExt lst = SOME (1::lst);


(* making a couple of odometers *)
val bb04 = bbProducer bbOdoIncr4 bbOdoExt (SOME []);
val bb05 = bbProducer (bbOdoIncr 5) bbOdoExt (SOME []);


(* a couple of helper function for traversing a bbSearch manually *)
fun inc BBEmpty = BBEmpty
  | inc (BBValue(s, increment, extend)) = increment ();

fun ext BBEmpty = BBEmpty
  | ext (BBValue(s, increment, extend)) = extend ();


(* a simple predicate to try and find states with all the same numbers *)
fun allEqual []         = true
  | allEqual [x]        = true
  | allEqual (x::y::xs) =
    if x = y then
        allEqual (x::xs)
    else
        false;

fun allEqualPred l []  = PENDING
  | allEqualPred l x   =
    if allEqual x then
        if length x = l then
            CORRECT
        else
            PENDING
    else
        INCORRECT