[php] issue with Bytes.fastGet

[Simn]

class Main {
    static function main() {
        var b = haxe.io.Bytes.alloc(10);
        var bd = b.getData();
        b.set(1,20);
        Sys.println(haxe.io.Bytes.fastGet(bd, 1));
    }
}

    static function main() {
        $b = haxe_io_Bytes::alloc(10);
        $bd = $b->b;
        $b->b[1] = chr(20);
        Sys::println(ord($bd[1]));
    }

This prints 0 instead of the expected 20. As usual I'm at a loss here because it "looks" like this should work by accessing $bd[1]. It works if I change that to $b->b[1] which in my mindset is equivalent.

@mockey @tml: What's my misconception here and what can we do about it?

[tml]

PHP values are "copy on write"; once you change the value in $b->$b (via $b->b[1] = chr(20);), the old value is copied into $bd, and they are no longer attached. You would have to do references ($bd =& $b->b) to make this work, but honestly, that's largely not considered very good PHP style.

(Whether or not that's good haxe style, I can't say as of yet; I'll leave that decision to you 👍 )

[mockey]

As the underlying type for BytesData is just a (Native)String in PHP (is this really good BTW?)
$bd = $b->b;
is passed by value here. So a quick fix would be passing by reference as @tml described above. A better fix would be maybe using an Array<Int> for BytesData...

[frabbit]

i guess it's because string manipulation is faster in some applications (http://www.sitepoint.com/high-performance-string-concatenation-in-php/), but i'm not sure if that's the general case.

[mockey]

Is string-concatenation needed for working with Bytes? For BytesBuffer maybe...

[frabbit]

@fponticelli why did you choose NativeString instead of NativeArray for BytesData?

[fponticelli]

@frabbit as I could possibly remember that.

[frabbit]

hehe, ok but i guess if it's a good idea to change this now.

[mockey]

Maybe because neko uses NativeString as well?

[frabbit]

oh, i wanted to say that it's not a good idea to change this now ;)

[Simn]

So what is a good idea?

[waneck]

As far as I know, normally PHP bytes manipulation is done with strings indeed

[mockey]

Uhm, just a question, is this really intended that b.getData() returns a reference to b.b (the BytesData object) and not its value (i.e. data)?