topical media & game development
lib-as-de-polygonal-ds-ArrayedStack.ax
lib-as-de-polygonal-ds-ArrayedStack.ax
(swf
)
[ flash
]
flex
Copyright (c) Michael Baczynski 2007
http://lab.polygonal.de/ds/
This software is distributed under licence. Use of this software
implies agreement with all terms and conditions of the accompanying
software licence.
package de.polygonal.ds
{
import de.polygonal.ds.Collection;
An arrayed stack.
<p>A stack is a LIFO structure (Last In, First Out).</p>
public class @ax-lib-as-de-polygonal-ds-ArrayedStack implements Collection
{
private var _stack:Array;
private var _size:int;
private var _top:int;
Initializes a stack to match the given size.
parameter: size The total number of elements the stack can store.
public function @ax-lib-as-de-polygonal-ds-ArrayedStack(size:int)
{
_size = size;
clear();
}
Indicates the top item.
returns: The top item.
public function peek():*
{
return _stack[int(_top - 1)];
}
Pushes data onto the stack.
parameter: obj The data.
public function push(obj:*):Boolean
{
if (_size != _top)
{
_stack[_top++] = obj;
return true;
}
return false;
}
Pops data from the stack.
returns: The top item.
public function pop():void
{
if (_top > 0) _top--
}
Reads an item at a given index.
parameter: i The index.
returns: The item at the given index.
public function getAt(i:int):*
{
if (i >= _top) return null;
return _stack[i];
}
Writes an item at a given index.
parameter: i The index.
parameter: obj The data.
public function setAt(i:int, obj:*):void
{
if (i >= _top) return;
_stack[i] = obj;
}
Checks if a given item exists.
returns: True if the item is found, otherwise false.
public function contains(obj:*):Boolean
{
for (var i:int = 0; i < _top; i++)
{
if (_stack[i] === obj)
return true;
}
return false;
}
Clears the stack.
public function clear():void
{
_stack = new Array(_size);
_top = 0;
}
Creates a new iterator pointing to the top item.
public function getIterator():Iterator
{
return new @fileIterator(this);
}
The total number of items in the stack.
public function get size():int
{
return _top;
}
Checks if the stack is empty.
public function isEmpty():Boolean
{
return _size == 0;
}
The maximum allowed size.
public function get maxSize():int
{
return _size;
}
Converts the structure into an array.
returns: An array.
public function toArray():Array
{
return _stack.concat();
}
Returns a string representing the current object.
public function toString():String
{
return "[@ax-lib-as-de-polygonal-ds-ArrayedStack, size= " + _top + "]";
}
Prints out all elements in the queue (for debug/demo purposes).
public function dump():String
{
var s:String = "[@ax-lib-as-de-polygonal-ds-ArrayedStack]";
if (_top == 0) return s;
var k:int = _top - 1;
s += "\n\t" + _stack[k--] + " -> front\n";
for (var i:int = k; i >= 0; i--)
s += "\t" + _stack[i] + "\n";
return s;
}
}
}
import de.polygonal.ds.Iterator;
import de.polygonal.ds.@ax-lib-as-de-polygonal-ds-ArrayedStack;
internal class @fileIterator implements Iterator
{
private var _stack:@ax-lib-as-de-polygonal-ds-ArrayedStack;
private var _cursor:int;
public function @fileIterator(stack:@ax-lib-as-de-polygonal-ds-ArrayedStack)
{
_stack = stack;
start();
}
public function get data():*
{
return _stack.getAt(_cursor);
}
public function set data(obj:*):void
{
_stack.setAt(_cursor, obj);
}
public function start():void
{
_cursor = _stack.size - 1;
}
public function hasNext():Boolean
{
return _cursor >= 0;
}
public function next():*
{
if (_cursor >= 0)
return _stack.getAt(_cursor--);
return null;
}
}
(C) Æliens
20/2/2008
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
