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Date: Wed, 26 Jun 2024 11:11:36 +0300
Message-ID: <CAL0xaBFStvKe+p2a_oSRS68PXoVEj12mBdegq9cgtGkUQDSqpw@mail.gmail.com>
Subject: Re: [PHP-DEV] [Early Feedback] Pattern matching
To: Rob Landers <rob@bottled.codes>
Cc: internals@lists.php.net
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From: arvids.godjuks@gmail.com (Arvids Godjuks)

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On Wed, 26 Jun 2024 at 11:00, Rob Landers <rob@bottled.codes> wrote:

>
>
> On Wed, Jun 26, 2024, at 09:54, Rob Landers wrote:
>
>
>
> On Wed, Jun 26, 2024, at 00:19, Morgan wrote:
>
> On 2024-06-26 08:24, Rob Landers wrote:
> > On Tue, Jun 25, 2024, at 20:23, Ilija Tovilo wrote:
>
> >> If null array values were indeed unobservable, then [] would be =3D=3D=
=3D to
> >> [null] (or at least =3D=3D), and a foreach over [null] would result in=
 0
> >> iterations. But neither of those are the case.
> >
> > I think there is a difference between an empty array and a null, and
> > that is (hopefully) self-evident. I=E2=80=99m talking about the infinit=
e nulls
> > IN the array. You can write a for loop of all possible keys until the
> > end of the universe, and all you will get is null. This is fairly easy
> > to prove. I'll wait... :p
> >
> What about the difference between an empty array an an array that
> contains a null (Ilija's example)?
>
> echo count([]);
> echo count([null]);
> echo count([null, null]);
> echo count([null, null, null]);
> echo count([null, null, null, null]);
> ...
>
> You're arguing that these are all the same array?
>
>
> If you are accessing them by index, yes, they are all the same array.
> There is no observable difference. I think we already covered that count(=
)
> would show the difference between them since it=E2=80=99s actually a coun=
t of known
> indices:
>
>
> Sorry, I=E2=80=99ve not yet had enough coffee, this should be:
>
> $arr =3D [];
>
> for($i =3D 0; $i < 4; $i++) var_dump($arr[$i]);
>
>
> Will output 4 nulls.
>
>
> =E2=80=94 Rob
>
>
> =E2=80=94 Rob
>

You are only half-correct.
It will also output 4 undefined index warnings in strict_types=3D1 mode :)
https://3v4l.org/DJ4AI

--=20

Arv=C4=ABds Godjuks
+371 26 851 664
arvids.godjuks@gmail.com
Telegram: @psihius https://t.me/psihius

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<div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">=
<div dir=3D"ltr" class=3D"gmail_attr">On Wed, 26 Jun 2024 at 11:00, Rob Lan=
ders &lt;rob@bottled.codes&gt; wrote:<br></div><blockquote class=3D"gmail_q=
uote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,2=
04);padding-left:1ex"><div class=3D"msg4718253297957168268"><u></u><div><di=
v><br></div><div><br></div><div>On Wed, Jun 26, 2024, at 09:54, Rob Landers=
 wrote:<br></div><blockquote type=3D"cite" id=3D"m_4718253297957168268qt"><=
div><br></div><div><br></div><div>On Wed, Jun 26, 2024, at 00:19, Morgan wr=
ote:<br></div><blockquote type=3D"cite" id=3D"m_4718253297957168268qt-qt"><=
div>On 2024-06-26 08:24, Rob Landers wrote:<br></div><div>&gt; On Tue, Jun =
25, 2024, at 20:23, Ilija Tovilo wrote:<br></div><div><br></div><div>&gt;&g=
t; If null array values were indeed unobservable, then [] would be =3D=3D=
=3D to<br></div><div>&gt;&gt; [null] (or at least =3D=3D), and a foreach ov=
er [null] would result in 0<br></div><div>&gt;&gt; iterations. But neither =
of those are the case.<br></div><div>&gt;=C2=A0<br></div><div>&gt; I think =
there is a difference between an empty array and a null, and=C2=A0<br></div=
><div>&gt; that is (hopefully) self-evident. I=E2=80=99m talking about the =
infinite nulls=C2=A0<br></div><div>&gt; IN the array. You can write a for l=
oop of all possible keys until the=C2=A0<br></div><div>&gt; end of the univ=
erse, and all you will get is null. This is fairly easy=C2=A0<br></div><div=
>&gt; to prove. I&#39;ll wait... :p<br></div><div>&gt;=C2=A0<br></div><div>=
What about the difference between an empty array an an array that=C2=A0<br>=
</div><div>contains a null (Ilija&#39;s example)?<br></div><div><br></div><=
div>echo count([]);<br></div><div>echo count([null]);<br></div><div>echo co=
unt([null, null]);<br></div><div>echo count([null, null, null]);<br></div><=
div>echo count([null, null, null, null]);<br></div><div>...<br></div><div><=
br></div><div>You&#39;re arguing that these are all the same array?<br></di=
v><div><br></div></blockquote><div><br></div><div>If you are accessing them=
 by index, yes, they are all the same array. There is no observable differe=
nce. I think we already covered that count() would show the difference betw=
een them since it=E2=80=99s actually a count of known indices:<br></div></b=
lockquote><div><br></div><div>Sorry, I=E2=80=99ve not yet had enough coffee=
, this should be:<br></div><div><br></div><div>$arr =3D [];</div><div><br><=
/div><div>for($i =3D 0; $i &lt; 4; $i++) var_dump($arr[$i]);<br></div><bloc=
kquote type=3D"cite" id=3D"m_4718253297957168268qt"><div><br></div><div>Wil=
l output 4 nulls.=C2=A0<br></div><div><br></div><div><br></div><div id=3D"m=
_4718253297957168268qt-sig121229152">=E2=80=94 Rob<br></div></blockquote><d=
iv><br></div><div id=3D"m_4718253297957168268sig121229152">=E2=80=94 Rob<br=
></div></div></div></blockquote></div><div><br></div>You are only half-corr=
ect.<div>It will also output 4 undefined index warnings in strict_types=3D1=
 mode :)=C2=A0<a href=3D"https://3v4l.org/DJ4AI">https://3v4l.org/DJ4AI</a>=
<br clear=3D"all"><div><br></div><span class=3D"gmail_signature_prefix">-- =
</span><br><div dir=3D"ltr" class=3D"gmail_signature"><div dir=3D"ltr"><div=
><br></div>Arv=C4=ABds Godjuks<div>+371 26 851 664</div><div><a href=3D"mai=
lto:arvids.godjuks@gmail.com" target=3D"_blank">arvids.godjuks@gmail.com</a=
></div><div>Telegram: @psihius=C2=A0<a href=3D"https://t.me/psihius" target=
=3D"_blank">https://t.me/psihius</a></div></div></div></div></div>

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