struct::prioqueue(n)          Tcl Data Structures         struct::prioqueue(n)



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NAME
       struct::prioqueue - Create and manipulate prioqueue objects

SYNOPSIS
       package require Tcl  8.2

       package require struct::prioqueue  ?1.4?

       ::struct::prioqueue ?-ascii|-dictionary|-integer|-real? ?prioqueueName?

       prioqueueName option ?arg arg ...?

       prioqueueName clear

       prioqueueName remove item

       prioqueueName destroy

       prioqueueName get ?count?

       prioqueueName peek ?count?

       prioqueueName peekpriority ?count?

       prioqueueName put item prio ?item prio ...?

       prioqueueName size

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DESCRIPTION
       This package implements a simple priority queue using nested tcl lists.

       The command ::struct::prioqueue creates a new priority queue with
       default priority key type -integer. This means that keys given to the
       put subcommand must have this type.

       This also sets the priority ordering. For key types -ascii and
       -dictionary the data is sorted in ascending order (as with lsort
       -increasing), thereas for -integer and -real the data is sorted in
       descending order (as with lsort -decreasing).

       Prioqueue names are unrestricted, but may be recognized as options if
       no priority type is given.

       ::struct::prioqueue ?-ascii|-dictionary|-integer|-real? ?prioqueueName?
              The ::struct::prioqueue command creates a new prioqueue object
              with an associated global Tcl command whose name is
              prioqueueName. This command may be used to invoke various
              operations on the prioqueue.  It has the following general form:

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

       prioqueueName clear
              Remove all items from the prioqueue.

       prioqueueName remove item
              Remove the selected item from this priority queue.

       prioqueueName destroy
              Destroy the prioqueue, including its storage space and
              associated command.

       prioqueueName get ?count?
              Return the front count items of the prioqueue (but not their
              priorities) and remove them from the prioqueue.  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 no or too few
              items in the prioqueue, this command will throw an error.

       prioqueueName peek ?count?
              Return the front count items of the prioqueue (but not their
              priorities), without removing them from the prioqueue.  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 no or
              too few items in the queue, this command will throw an error.

       prioqueueName peekpriority ?count?
              Return the front count items priority keys, without removing
              them from the prioqueue.  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 no or too few items in the queue, this
              command will throw an error.

       prioqueueName put item prio ?item prio ...?
              Put the item or items specified into the prioqueue. prio must be
              a valid priority key for this type of prioqueue, otherwise an
              error is thrown and no item is added.  Items are inserted at
              their priority ranking. Items with equal priority are added in
              the order they were added.

       prioqueueName size
              Return the number of items in the prioqueue.

BUGS, IDEAS, FEEDBACK
       This document, and the package it describes, will undoubtedly contain
       bugs and other problems.  Please report such in the category struct ::
       prioqueue of the Tcllib SF Trackers
       [http://sourceforge.net/tracker/?group_id=12883].  Please also report
       any ideas for enhancements you may have for either package and/or
       documentation.

KEYWORDS
       ordered list, prioqueue, priority queue

CATEGORY
       Data structures

COPYRIGHT
       Copyright (c) 2003 Michael Schlenker <mic42@users.sourceforge.net>




struct                                1.4                 struct::prioqueue(n)
