Can we support exclude some specific Exception when catch Exception?

[gitHusband]

Description

Hi,

Can we support exclude some specific Exception when catch Exception?

I don't want to catch RuntimeException in Child catching block, but catch RuntimeException in Parent catching block.
(NOTE that RuntimeException just an example, not real)

For now, I can handle it like test and test1 method.

But can we support any other more concise approach? such as test2 method?

For example,

<?php

class Example
{
    public function test()
    {
        // Parent catching
        try {
            // Child catching
            try {
                // Throw Exception
            } catch (\Exception $e) {
                // exclude \RuntimeException and re-throw it
                if ($e instanceof \RuntimeException) 
                    throw $e;
                
                return false;
            }
        } catch (\RuntimeException $e) {
            return true;
        }
    }

    public function test1()
    {
        // Parent catching
        try {
            try {
                // Throw Exception
            } catch (\RuntimeException $e) {
                // exclude \RuntimeException and re-throw it
                throw $e;
            } catch (\Exception $e) {
                return false;
            }
        } catch (\RuntimeException $e) {
            return true;
        }
    }

    public function test2()
    {
        // Parent catching
        try {
            // Child catching
            try {
                // Throw Exception
            } 
            // catch \Exception but exclude \RuntimeException
            catch (\Exception && !\RuntimeException $e) {
                return false;
            }
        } catch (\RuntimeException $e) {
            return true;
        }
    }
}

[damianwadley]

For the most part, I think the answer to this is going to be no. For one main reason:

The current solution is very simple: catch and re-throw the exception if you don't want to handle it (and you can union multiple types together if there's more than one you want to ignore). I don't think that's too much to ask for. It's also the typical way to handle this in other languages; on that subject, do you know of any other programming languages which have this sort of "catch X but not Y" ability?

That aside, note that it should probably be a & to match the existing intersection syntax, and I have a question of whether ! or ~ is more appropriate for negation.

That said, if you think this is still a good idea then I encourage you to check out the RFC process. It starts with you putting some more time and thought into this idea, considering multiple approaches or alternatives to it, and presenting your thoughts to the internals mailing list for discussion.
https://wiki.php.net/rfc/howto

[gitHusband]

@damianwadley

Thank you for your explain.

Sorry, test2 is a stupid example, as you say, \Exception & ~\RuntimeException $e looks great.

I don't know any other programming languages which have this sort of "catch X but not Y" ability.
I just had this sudden idea and want a answer.

[KapitanOczywisty]

I was thinking about proposing a way to continue to the next catch without using multiple try/catch blocks:

try {
    // Throw SpecialException
} catch (\SpecialException $e) {
    if($e->getCode() === 123) return;
    // continue to catch(\Exception $e)
    continue_to_next_matching_catch_or_throw_if_not_matched;
} catch (\OtherSpecialException $e) {
    // not called
} catch (\Exception $e) {
    // called for \SpecialException
}