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struct::prioqueue(3tcl) Tcl Data Structures struct::prioqueue(3tcl) 





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










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:

  

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

  

  
Remove all items from the prioqueue.

  

  
Remove the selected item from this priority queue.

  

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

  

  
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.

  

  
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.

  

  
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.

  

  
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.

  

  
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 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


ordered list, prioqueue, priority queue






CATEGORY


Data structures






COPYRIGHT


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








  

    1.4
    tcllib