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Date: Tue, 5 Nov 2013 15:03:37 +0200
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Subject: PHP RFC: Deffering functions by arguments (count or/and type)
From: oleg@poludnenko.info (Oleg Poludnenko)

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Hi,

My idea is somehow related to this one: Syntax for variadic
functions<https://wiki.php.net/rfc/variadics>
It is not a competitive idea but a supplemental one.

So, the main point is to write different implementations for the functions
with the same name, but with different of arguments count or/and type:

class Config { /** * Returns property value * @param string $key *
@returnmixed */
public function prop($key) { return isset($this->prop[$key]) ? $this->prop[
$key] : null; } /** * Sets property value * @param string $key *
@parammixed $value *@returnConfig */
public function prop($key, $value) { $this->prop[$key] = $value; return
$this; } }

Also it will be possible to change arguments during inheritance:

class Figure { /** * Calculate perimeter of an arbitrary figure *
@paramarray $angles *@returnint */
public function calcPerimeter(array $angles) { return array_sum($angles); }
} class Square extends Figure { /** * Calculate perimeter of a square
*@paramint $angle *@returnint */
public function calcPerimeter($angle) { return 4 * $angle; } } class
Rectangle extends Figure { /** * Calculate perimeter of a rectangle *
@paramint $height *@paramint $width *@returnint */
public function calcPerimeter($height, $width) { return 2 * ($height +
$width); } }

The advantages of the syntax are:

   - It's immediately clear what function implements.
   - The function becomes cleaner, without a lot of if-else constructions.
   - A great opportunity to change function arguments during inheritance.


Regards,
Oleg Poludnenko

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