next-queue-elementQueue Managementon-queue-pnth-queue-elementGoTo Top

nth-queue-element   n queue => queue-element[Generic Function]

Purpose
Return the nth queue element on queue.

Method signatures

nth-queue-element  (n fixnum) (queue queue) => queue-element or nil

Package   :gbbopen

Module   :queue

Arguments and values

n     A fixnum
queue     A GBBopen queue
queue-element     A GBBopen queue element objec

Returns
The specified queue element or nil if none exists.

Description
Returns the nth element in queue (zero origin) or nil if the queue is shorter than n. If n is negative, return the nth element counting backward from the end of the queue (one origin).

See also
    first-queue-element
    last-queue-element

Examples
Return the first element on pending-ksas (equivalent to first-queue-element):

  > (nth-queue-element 0 pending-ksas)
  #<ksa 2217>
  >
Return the last element on pending-ksas (equivalent to last-queue-element):
  > (nth-queue-element -1 pending-ksas)
  #<ksa 2372>
  >


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