Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:130677
Message-ID: <6dddead1-cee2-43e6-b943-ca45823f30b9@bastelstu.be>
Date: Mon, 20 Apr 2026 22:09:36 +0200
Precedence: list
MIME-Version: 1.0
Subject: Re: [PHP-DEV] [RFC] Context Managers
To: Larry Garfield <larry@garfieldtech.com>
Cc: php internals <internals@lists.php.net>
References: <a087d9fa-112a-4631-9c84-3efae641e0db@app.fastmail.com>
 <4985896b-c80a-4302-912e-9f572a260fb5@app.fastmail.com>
 <cf6ac562-7e6f-4eca-a514-6aa3c9692461@app.fastmail.com>
 <a748c98a-180a-475f-93a7-b802c21138e2@app.fastmail.com>
Content-Language: en-US
In-Reply-To: <a748c98a-180a-475f-93a7-b802c21138e2@app.fastmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
From: tim@bastelstu.be (=?UTF-8?Q?Tim_D=C3=BCsterhus?=)

Hi

Am 2026-04-15 16:52, schrieb Larry Garfield:
> The finally path is only reached in case of a successful exit.  
> Therefore there is no exception to pass in, and thus returning an 
> exception is meaningless. […]

That's not at all how I understood the RFC text (and I admittedly didn't 
look at the desugaring):

> If exitContext() returns a throwable (either a new one or the one it 
> was passed), it will be rethrown.

I understood the “it” in “it will be rethrown” as “the returned 
Throwable is thrown”, not “the Throwable that was caught is thrown”. 
That is also what is mentioned in your email 
https://news-web.php.net/php.internals/130413:

> or a throwable, which will then get thrown

and

> If there's a reason to wrap and rethrow the exception, do that and 
> return the new exception

And that is what the second half of my email 
https://news-web.php.net/php.internals/130479 is based on, particularly 
the joke in the footnote. Why has this misunderstanding not been pointed 
out back then?

------------

So based on the desugaring that Rob thankfully looked at, of all the 
information in a `?\Throwable` return type, only a single bit is used - 
and only in some cases. I don't see how we can meaningfully explain to 
users that throwing away all the other information is the expected behavior.

Best regards
Tim Düsterhus