function 
    /usr/local/lib/janet/spork/misc.janet  on  line  518 , column  1 
    (insert-sorted-by  arr  f  &  xs )
    Insert  elements  in  `arr`  such  that  it  remains  sorted  by  the  value  
    returned  when  `f`  is  called  with  the  element , comparing  the  values  
    with  `<` .  If  `arr`  is  not  sorted  beforehand , the  results  are  
    undefined.  Returns  `arr` .