struct::stack(3tcl) Tcl Data Structures struct::stack(3tcl)
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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 pro-
vided here can be reached through a subcommand of this command.
Note: As of version 1.3.3 of this package a critcl based C implementa-
tion is available. This implementation however requires Tcl 8.4 to run.
The ::struct::stack command creates a new stack object with an associ-
ated 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 re-
moving 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 re-
quest, 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 re-
turns 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 re-
turn 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 re-
quest, 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 out-
put 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
tcllib 1.5.3 struct::stack(3tcl)