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Date: Mon, 24 Jun 2024 11:31:36 +0200
Message-ID: <CAPzBOBOTSCCKDR4pDocr4xW+oEXJ27YizgPLkn1PGR9nyPU7ww@mail.gmail.com>
Subject: Re: [PHP-DEV] [Early Feedback] Pattern matching
To: Hendra Gunawan <the.liquid.metal@gmail.com>
Cc: php internals <internals@lists.php.net>
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From: landers.robert@gmail.com (Robert Landers)

On Mon, Jun 24, 2024 at 7:04=E2=80=AFAM Hendra Gunawan
<the.liquid.metal@gmail.com> wrote:
>
> I agree that this proposal should be proposed as a whole. If we break
> it down into smaller parts, there is a chance some features will not
> pass.

This is exactly my concern and I fear we will be dealing with the
repercussions of a non-well-thought-out sub-feature for years to come.

Why does `new Pattern()` have the ability to accept patterns as a
parameter? Can other code do that as well? Why is @($thing) a thing? @
is already an operator so seeing it used like this is strange. Same
with ~ . It's also weird to see `?` on the left hand side of a
literal.

PHP already has variable-variables, so use those instead of @(): $foo
is $$mypattern.

There's no need to use `?` to check for existence on a key, so this:

$arr is ['a' =3D> string, ?'b' =3D> string, ...];

should be this:

$arr is ['a' =3D> string, 'b' =3D> ?string, ...];

because $arr['non-existent-key'] is NULL.

~ has no meaning in mode 0, only in strict mode, but will force people
in mode 0 to work like they are in strict mode or litter their code
with ~'s. PHP is duck-typed and making it act like it isn't is just
bad DX. Further, it isn't clear how it will affect literals since it
is also bitwise-not.