bsearch

bsearch(Key, Array) -> bsearch(Key, 0, array:size(Array) - 1, Array). %Default range

bsearch(Key, From, To, Array) when From <= To -> %when there's hope
    Mid = (To + From) div 2,
    MidValue = array:get(Mid, Array),
    if
        Key < MidValue -> bsearch(Key, From, Mid - 1, Array);
        Key = MidValue -> Mid;
        Key > MidValue -> bsearch(Key, Mid + 1, To, Array);
    end;

bsearch(_Key, _From, _To, _Array) -> not_found; %When it's hopeless, return -1 is too mainstream