Class: Stack

• Inheritance
• Description
• Class protocol
  • instance creation
• Instance protocol
  • accessing
  • enumerating
• Examples

Inheritance:

   Object
   |
   +--Collection
      |
      +--SequenceableCollection
         |
         +--OrderedCollection
            |
            +--Stack

Package:

stx:libbasic2

Category:

Collections-Ordered

Version:

rev: 1.16 date: 2021/06/03 07:03:45

user: cg

file: Stack.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

A simple implementation of a Stack.

Notice, this is simply syntactic sugar - all functionality is
already provided by the OrderedCollection class 
(addLast <==> push / removeLast <==> pop / last <==> top)

[complexity:]
    see OrderedCollection

copyright
COPYRIGHT (c) 1996 by Claus Gittinger
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

 new

(comment from inherited method)
create a new, empty OrderedCollection

Instance protocol:

 drop: n

remove n elements from the top of the stack.

 pop

Answer the object on top of the stack.

 pop: numElem

Pop and discard top numElems and answer the receiver.
Caveat: pop: is a misleading name; should propably be called drop:

** This is an obsolete interface - do not use it (it may vanish in future versions) **

 push: anObject

Push anObject onto the top of the stack.
Return the pushed object.

 top

Answer (without removing) the object on top of the stack.

 do: aBlock

Evaluate aBlock for each object on the stack, from top to bottom.

 reverseDo: aBlock

Evaluate aBlock for each object on the stack, from bottom to top.

Examples:

  |aStack|

  aStack := Stack new.
  Transcript showCR:aStack.
  Transcript showCR:'push 1: '.
  aStack push:1.
  Transcript showCR:'push 2: '.
  aStack push:2.
  Transcript showCR:'push 3: '.
  aStack push:3.
  Transcript showCR:aStack.
  Transcript show:'pop: '; showCR:(aStack pop).
  Transcript show:'pop: '; showCR:(aStack pop).
  Transcript show:'pop: '; showCR:(aStack pop).
  Transcript showCR:aStack.

  |aStack|

  aStack := Stack new.
  aStack push:1.

  aStack pop.
  aStack pop.