Description:
------------
I often find myself being in the situation where I need more advanced ways to implode() something. For example, a way to implode an array into:

"table1 AS alias1, table2 AS alias2, table3 AS alias3"

or:

"var1=value1&var2=value2&var3=value3"


I would like to make 3 suggestions to implement such a functionality in PHP.


1) Extend implode so that it can handle a second (or more?) "glue" argument.

$vars = array(
	'var1' => 'value1',
	'var2' => 'value2',
	'var3' => 'value3'
);

or maybe it would need a multidimensional array:

$vars = array(
	array('var1', 'value1'),
	array('var2', 'value2'),
	array('var3', 'value3')
);
echo implode($vars, '=', '&');

// Would print: var1=value1&var2=value2&var3=value3

The problem here is that implode would need to get its arguments in a different order. Perhaps, this could be solved by creating a new function. 


2) Modify array_map() so that, when the third argument is a string, it is always passed along as an extra argument to all the function calls:

$vars = array(
	array('var1', 'value1'),
	array('var2', 'value2'),
	array('var3', 'value3')
);
echo implode('&', array_map('implode', $vars, '='));

// Would print: var1=value1&var2=value2&var3=value3


3) This is probably the most powerfull and elegant solution. (My personal favourite) Modify the __toString() magic method so that, when an object is passed to a function that needs a string as input, __toString() is called. In this example __toString() could be something like: 

function __toString() {
   return $this->name.'='.$this->value;
}

And the implode() code could look like:

$vars = array(
	new urlVar('var1', 'value1'),
	new urlVar('var1', 'value1'),
	new urlVar('var1', 'value1')
);
echo implode($vars, '&');
// Would print: var1=value1&var2=value2&var3=value3

This could also produce more complex strings like:

"WHERE var1='value1' AND var2='value2' OR var3='value3'"