> -----Original Message----- > From: Larry Garfield <la...@garfieldtech.com> > Sent: Wednesday, June 29, 2022 12:39 PM > To: php internals <internals@lists.php.net> > Subject: Re: [PHP-DEV] [RFC] Exception type hint > > On Wed, Jun 29, 2022, at 10:42 AM, Guilliam Xavier wrote: > > Hi (note: your message was flagged as spam), > > > >> https://github.com/php/php-src/issues/8843 > > > > So I understand it as having a "true code" equivalent for the > > `@throws` phpDoc comment (similar to type declarations for `@param` > > and `@return`)? which would also be checked at run-time? > > > > Just my 2 cents on that (let's call it "exception specification"): > > > > 1. IMHO, it shouldn't be mixed in the return type declaration (with > > a union-like syntax) but separated and independent (e.g. with a > > `throws` keyword, and pipes [or commas] between multiple exception > > classes) > > 2. AFAIK, Java has it (mandatory to compile for "checked > > exceptions", sometimes controversial), C++ used to have it > > (runtime-checked) but dropped it (and introduced `noexcept` instead); > > I don't know of any dynamic language that has it > > > > You would also need to define how it plays with inheritance (and > > reflection), and what exactly should happen when a function throws an > > exception it didn't "declare"... > > > > PS: I also found some old feature requests: > > - https://externals.io/message/4424 > > - https://bugs.php.net/bug.php?id=42251 > > - https://bugs.php.net/bug.php?id=62404 > > - https://bugs.php.net/bug.php?id=67312 > > > > Regards, > > Side Note: Please don't top post. > > On the subject of checked exceptions, I *highly* recommend this writeup > from the lead of the Midori language[1]. It's long, but there's a section > specifically on exceptions (no deep link, just search the page for it) that > goes > into a lot of detail about exceptions, checked exceptions, and the ways in > which both fail. It's absolutely worth everyone's time. > > The summary for the short-timed is that the only way exceptions work, from > a reliability standpoint, is if they are 1) Rare and 2) Strictly checked and > 3) > Have really good syntactic shorthand support. And checked exceptions > without the other two are a recipe for hell. Basically, it only works if > exceptions become an alternate syntax for an Either monad or Go's multi- > return. > > Since PHP is a long, long way from there, I don't believe checked exceptions > would be wise, or even slightly a good idea. Not until/unless it's done as > part > of a global rethink of error handling that reimagines how exceptions and > errors work at a fundamental level. And that couldn't be done in a BC way > with the current practice of "I dunno, throw, YOLO" in PHP exceptions, so > they'd have to be some other, different channel. We are definitely not > ready for that kind of fundamental rethink of how error handling works in > PHP. > > [1] http://joeduffyblog.com/2016/02/07/the-error-model/ > > -- > PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: > https://www.php.net/unsub.php
There's also a decent article here https://www.artima.com/articles/the-trouble-with-checked-exceptions where Anders Hejlsberg discusses the problems he sees with checked exceptions. -Jeff -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
