NAME

       struct::stack - Create and manipulate stack objects

SYNOPSIS

       package require Tcl  8.4

       package require struct::stack  ?1.5.3?

       stackName option ?arg arg ...?

       stackName clear

       stackName destroy

       stackName get

       stackName getr

       stackName peek ?count?

       stackName peekr ?count?

       stackName trim ?newsize?

       stackName trim* ?newsize?

       stackName pop ?count?

       stackName push item ?item...?

       stackName size

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DESCRIPTION

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

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

       Note: As of version 1.3.3 of this package a critcl based C  implementation  is  available.
       This implementation however requires Tcl 8.4 to run.

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

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

       stackName clear
              Remove all items from the stack.

       stackName destroy
              Destroy the stack, including its storage space and associated command.

       stackName get
              Returns the whole contents of the stack as a list, without removing them  from  the
              stack.

       stackName getr
              A variant of get, which returns the contents in reversed order.

       stackName peek ?count?
              Return  the top count items of the stack, without removing them from the stack.  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 enoughs items on the stack to  fulfull  the  request,  this
              command will throw an error.

       stackName peekr ?count?
              A variant of peek, which returns the items in reversed order.

       stackName trim ?newsize?
              Shrinks the stack to contain at most newsize elements and returns a list containing
              the elements which were removed. Nothing is done if the stack  is  already  at  the
              specified size, or smaller. In that case the result is the empty list.

       stackName trim* ?newsize?
              A  variant  of  trim  which performs the shrinking, but does not return the removed
              elements.

       stackName pop ?count?
              Return the top count items of the stack, and remove them from the stack.  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 enoughs items on the stack to fulfull the request, this command
              will throw an error.

       stackName push item ?item...?
              Push the item or items specified onto the stack.  If more than one item  is  given,
              they will be pushed in the order they are listed.

       stackName size
              Return the number of items on the stack.

BUGS, IDEAS, FEEDBACK

       This  document,  and  the  package  it  describes, will undoubtedly contain bugs and other
       problems.  Please report such in the category struct  ::  stack  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, matrix, queue, tree

CATEGORY

       Data structures