RM approval: 👍

Thank you for sorting this out. Please make a note in NEWS (if you think it's appropriate) so we can tell people about the change in behavior.

Yes, definitely please include in NEWS - it'll be removed as part of combining the entries for 8.5.0 (per https://github.com/php/php-src/blob/1cbaa6080758237fc6a292fd0d372ae309ac3b7a/docs/release-process.md#preparing-for-the-initial-stable-version-php-xy0) but would be useful for those testing out the alphas/betas

@Crell Please confirm whether this is the approach you want to go with.

Thanks for the inputs. /cc @nikic I'm guessing PHP-Parser will want a similar patch applied.

This makes the examples in RFC invalid. Any chance to update them?

I have no idea what standard procedure is here. I can update the RFC if that's appropriate, but I'm not sure if that's appropriate.

@Crell Given this was discussed publicly I think adjusting the examples is appropriate. For the sake of transparency you may add it to a change log at the top of the page, with a link to the discussion.

I have added an Errata section to my RFCs more than once. Last time https://wiki.php.net/rfc/marking_return_value_as_important#errata

I'd still change the example. It's often the only thing people look at.

I have added an Errata section to the RFC, referencing this issue, and updated the examples accordingly:

https://wiki.php.net/rfc/pipe-operator-v3#errata

Hi, is this really necessary when the parentheses do not add any value? For example if the arrow function is the last one in the chain:

$result = $input |> $foo->doFoo(...) |> fn ($x) => $foo->doBar($x);

Adding parentheses around the arrow function is now required but does not disambiguate anything.

We could work around this by scanning the AST of the fn body, to check whether it contains |>, but ... $input |> fn ($x) => ($x + 1 |> $foo->doFoo(...)); and $input |> fn ($x) => $x + 1 |> $foo->doFoo(...); for example are not distinguishable from the AST, even though the former would be fine ("last in chain").
There are such caveats which make it annoying; one simple rule "always parens-wrap it" is clearer.