NAME

       struct::queue - Create and manipulate queue objects

SYNOPSIS

       package require Tcl  8.4

       package require struct::queue  ?1.4.5?

       queueName option ?arg arg ...?

       queueName clear

       queueName destroy

       queueName get ?count?

       queueName peek ?count?

       queueName put item ?item ...?

       queueName unget item

       queueName size

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DESCRIPTION

       The ::struct namespace contains a commands for processing finite queues.

       It  exports  a  single  command,  ::struct::queue.  All functionality provided here can be
       reached through a subcommand of this command.

       Note: As of version 1.4.1 of this package a critcl based C  implementation  is  available.
       This implementation however requires Tcl 8.4 to run.

       The  ::struct::queue  command  creates  a  new  queue object with an associated global Tcl
       command whose name is queueName.  This command may be used to invoke various operations on
       the queue.  It has the following general form:

       queueName option ?arg arg ...?
              Option  and  the  args  determine the exact behavior of the command.  The following
              commands are possible for queue objects:

       queueName clear
              Remove all items from the queue.

       queueName destroy
              Destroy the queue, including its storage space and associated command.

       queueName get ?count?
              Return the front count items of the queue and remove them from the queue.  If count
              is  not specified, it defaults to 1.  If count is 1, the result is a simple string;
              otherwise, it is a list.  If specified, count must be greater than or equal  to  1.
              If  there  are  not  enough items in the queue to fulfull the request, this command
              will throw an error.

       queueName peek ?count?
              Return the front count items of the queue, without removing them  from  the  queue.
              If count is not specified, it defaults to 1.  If count is 1, the result is a simple
              string; otherwise, it is a list.  If specified, count must be greater than or equal
              to  1.   If  there  are  not enough items in the queue to fulfull the request, this
              command will throw an error.

       queueName put item ?item ...?
              Put the item or items specified into the queue.  If more than one  item  is  given,
              they will be added in the order they are listed.

       queueName unget item
              Put  the  item into the queue, at the front, i.e. before any other items already in
              the queue. This makes this operation the complement to the method get.

       queueName size
              Return the number of items in the queue.

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes,  will  undoubtedly  contain  bugs  and  other
       problems.   Please  report  such  in  the  category struct :: queue of the Tcllib Trackers
       [http://core.tcl.tk/tcllib/reportlist].  Please also report any ideas for enhancements you
       may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note further that attachments are strongly preferred over inlined patches. Attachments can
       be made by going to the Edit form of the ticket immediately after its creation,  and  then
       using the left-most button in the secondary navigation bar.

KEYWORDS

       graph, list, matrix, pool, prioqueue, record, set, skiplist, stack, tree

CATEGORY

       Data structures