stack(3tcl)


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

______________________________________________________________________________

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.

KEYWORDS

   graph, matrix, queue, tree

CATEGORY

   Data structures





Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.