Tcl Library Source Code

[comment {-*- tcl -*-}]
[manpage_begin struct::queue n 1.4.5]
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[moddesc   {Tcl Data Structures}]
[titledesc {Create and manipulate queue objects}]
[category  {Data structures}]
[require Tcl 8.4]
[require struct::queue [opt 1.4.5]]
[description]

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

[para]

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

[para]

[emph 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.

[para]

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

[list_begin definitions]

[call [arg queueName] [cmd option] [opt [arg "arg arg ..."]]]

[arg Option] and the [arg arg]s determine the exact behavior of the
command.  The following commands are possible for queue objects:

[call [arg queueName] [cmd clear]]

Remove all items from the queue.

[call [arg queueName] [cmd destroy]]

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

[call [arg queueName] [cmd get] [opt "[arg count]"]]

Return the front [arg count] items of the queue and remove them from
the queue.  If [arg count] is not specified, it defaults to 1.  If
[arg count] is 1, the result is a simple string; otherwise, it is a
list.  If specified, [arg 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.

[call [arg queueName] [cmd peek] [opt "[arg count]"]]

Return the front [arg count] items of the queue, without removing them
from the queue.  If [arg count] is not specified, it defaults to 1.
If [arg count] is 1, the result is a simple string; otherwise, it is a
list.  If specified, [arg 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.

[call [arg queueName] [cmd put] [arg item] [opt "[arg "item ..."]"]]

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

[call [arg queueName] [cmd unget] [arg item]]

Put the [arg 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 [method get].

[call [arg queueName] [cmd size]]

Return the number of items in the queue.

[list_end]

[vset CATEGORY {struct :: queue}]
[include ../common-text/feedback.inc]
[manpage_end]