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Date: Tue, 14 Feb 2012 13:05:33 +0100
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To: Pedro Pereira <mrpedro17@gmail.com>
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Subject: Re: [PHP-DEV] New Array function - limited push
From: patrickallaert@php.net (Patrick ALLAERT)

2012/2/14 Pedro Pereira <mrpedro17@gmail.com>:
> Hi. I'm Pedro and I'm from Portugal.
>
> I've been working with php for a while but only now i decided to try my
> luck and propose a new array function that will become handy for many
> people :)
>
> This function adds new elements to the end of an array but limits the
> amount of total elements it can have, by eliminating the oldest entries.
>
> *Example:*
> Array limit: 4
> 1, 2, 3, 4 -> 4 elements
>
> When you try to add a fifth element:
> 2, 3, 4, 5 -> $ elements
>
> The good thing is that, even if you in the middle decide to limit the arr=
ay
> to 10, it will store 10 elements but if you decide to put an inferior arr=
ay
> limit, it will remove the oldest entries until the limit size is achieved=
.
>
> Example:
> Limit 6 elements:
> 1, 2, 3, 4, 5, 6 -> 6 elements
>
> Limit 3
> When you try to add a new element:
> 5, 6, 7 -> 3 elements
>
> The function is written bellow:
>
> function array_push_limited(&$arrayValues, $newElement, $limit){
> $count =3D count($arrayValues);
> =C2=A0if($count =3D=3D 0){
> $arrayValues[0] =3D $newElement;
> }
> else if($count < $limit){
> array_push($arrayValues, $newElement);
> }
> else if ($count =3D=3D $limit) {
> array_shift($arrayValues);
> array_push($arrayValues, $newElement);
> }
> else if ($count > $limite) {
> do{
> array_shift($arrayValues);
> } while(count($arrayValues) > $limit - 1);
> array_push($arrayValues, $newElement);
> }
> }
>
> I have some more proposals but in time, after I improve them, I will send
> an email with them.
>
> I hope you see an advantage into put this as an array function for php.
>
> *Regards,*
> *Pedro Pereira*

Hi Pedro,

I suggest you to use array_splice() to achieve this.
There is no real benefit to implement such a new array function as
this is probably way too specific to be able to push elements and
always being able to provide an array dimension at every single
function calls.
If the size isn't supposed to change, then you might want to try
defining a new Spl class to implement a circular buffer where the size
would be specified at creation time. You might want to take some
inspiration from the SplFixedArray class.

Regards,
Patrick