<?php
/**
* JAVA Autoboxing (part of Lotos Framework)
*
* Copyright (c) 2005-2010 Artur Graniszewski ([email protected])
* All rights reserved.
*
* @category Library
* @package Lotos
* @subpackage DataTypes
* @copyright Copyright (c) 2005-2010 Artur Graniszewski ([email protected])
* @license GNU LESSER GENERAL PUBLIC LICENSE Version 3, 29 June 2007
* @version $Id$
*/
// load required library
include("./variablesManager.php");
/**
* Example class.
*
* Note: in order to use AutoBoxing, your class need to extend "AutoBoxedObject" class.
*/
class Integer extends AutoBoxedObject
{
public $value = 0;
public function __construct($value) {
// TYPE ENFORCING
if($value && !is_int ($value) && !is_float($value)) {
throw new Exception('The new value is not an Integer!!!');
}
$this->value = (int)$value;
}
public function __toString() {
// NOTE: this must be a string, PHP forbids returning different type of variables in __toString() methods.
return "{$this->value}";
}
public function toHex() {
$x = strtoupper(dechex($this->value));
$y = ceil(strlen($x) / 2);
return str_pad($x, $y * 2, '0', STR_PAD_LEFT);
}
}
/**
* Initializes a newly created Integer object.
* @return Integer created String object
*/
function & integer($value = null) {
$x = & VariablesManager::getNewPointer(new Integer($value));
return $x;
}
// 1) We're setting $x as an Integer object
$x = & integer();
// 2) Now we are changing $x value to 10
// NOTE: PHP without enabled autoboxing would destroy the Integer object and set $x as simple integer type
$x = 10;
// 3) Now we are checking, that $x is still an object
echo "<h3>Integer autoboxing:</h3>";
echo 'The initial value of $x variable is "'.$x.'"<br />';
echo 'The initial datatype of $x variable is '.gettype($x).(is_object($x) ? ' ('.get_class($x).')': '').'<br />';
// this line would raise FATAL_ERROR withou autoboxing:
echo 'The hex value of $x is 0x'.$x->toHex().'<br />';
// 4) Now we are trying to change $x value to a invalid integer value
echo "<h3>Type enforcing:</h3>";
try {
$x = "aaaa"; // invalid value, valid integer should contain digits only
} catch (Exception $e) {
echo 'Exception detected: Cannot change the integer value of $x to "aaaa", the new value should contain digits only<br />';
echo "Original exception message: ".$e->getMessage()."<br />";
}
// 5) Lets do some math...
echo "<h3>Basic math:</h3>";
echo '<strong>Impossible becomes possible: adding two objects in PHP</strong>:<br />';
$x = & integer(0);
$y = & integer(10);
$z = & integer(20);
// PLEASE NOTE the quotes surrounding the variables names, without it PHP would return '1' instead the true
// value of integers objects (because it would not use __toString() method to do the math!)
$x = "$y" + "$z" + 5;
echo 'The initial value of $y variable is "'.$y.'"<br />';
echo 'The initial datatype of $y variable is '.gettype($y).(is_object($y) ? ' ('.get_class($y).')': '').'<br />';
echo 'The initial value of $z variable is "'.$z.'"<br />';
echo 'The initial datatype of $z variable is '.gettype($z).(is_object($z) ? ' ('.get_class($z).')': '').'<br />';
echo '<u>The result of $x = $y + $z + 5 is "'.$x.'"</u><br />';
echo 'The datatype of $x (sum) variable is '.gettype($x).(is_object($x) ? ' ('.get_class($x).')': '').'<br />';
// this line would raise a FATAL_ERROR without autoboxing enabled:
echo 'The hex value of $x is 0x'.$x->toHex().'<br />';
echo '<br /><strong>We can also do other math operations, for example divide two objects: </strong><br />';
$x = & integer(0);
$y = & integer(20);
$z = & integer(10);
// PLEASE NOTE the quotes surrounding the variables names, without it PHP would return '1' instead the true
// value of integers objects (because it would not use __toString() method to do the math!)
$x = "$y" / "$z";
echo 'The initial value of $y variable is "'.$y.'"<br />';
echo 'The initial value of $z variable is "'.$z.'"<br />';
echo '<u>The result of $x = $y / $z is "'.$x.'"</u><br />';
echo 'The hex value of $x is 0x'.$x->toHex().'<br />';
echo '<br /><strong>This behaviour gives us some new C-like functionality</strong><br />';
$x = & integer(0);
$y = & integer(20);
$z = & integer(7);
// PLEASE NOTE the quotes surrounding the variables names, without it PHP would return '1' instead the true
// value of integers objects (because it would not use __toString() method to do the math!)
$x = "$y" / "$z";
echo 'The initial value of $y variable is "'.$y.'"<br />';
echo 'The initial value of $z variable is "'.$z.'"<br />';
echo '<u>The result of $x = $y / $z is "'.$x.'"</u><br />';
echo 'The hex value of $x is 0x'.$x->toHex().'<br />';
echo "Why 2.00 and not 2.85? Because in C and C# operation: 20 / 7 = 2.85 converted to int becomes 2<br />";
echo "Ofcourse you can freely change this behaviour in your custom Integer class<br />";
echo "<h3>Remember, you can easily create your own data types, like float, double, utf-8 string, etc.!</h3>";
echo "...using this mechanism you can even try to override default mathematical operators like +/*-!<br />";
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