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Date: Fri, 26 Mar 2021 22:00:28 +0000
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Subject: Re: [PHP-DEV] Making "match" catch exceptions
From: rowan.collins@gmail.com (Rowan Tommins)

On 26/03/2021 16:45, Olle Härstedt wrote:
> That made me think of a recent
> extension to OCaml which makes it possible to catch exceptions in a
> match-expressions (here's one blog post about it:
> https://blog.janestreet.com/pattern-matching-and-exception-handling-unite/).


That's an interesting idea. I wonder if it would provide a way to 
implement the "data-flow" or "expression context" exception handling I 
was discussing on a different thread recently.

Looking at my previous example:

try {
    $foo = doSomething() + $bar;
}
catch ( SomeException $e ) {
    $foo = $bar;
}

Would become something like this:

$foo = match($temp = doSomething()) {
    exception SomeException => 0,
    default => $temp
} + $bar;


Hm, that's not the most elegant; even if we could avoid the $temp 
assignment, the "default to myself" seems superfluous for this use case.

I can definitely see the feature having its use cases, though, was just 
kicking this around as a thought experiment.

Regards,

-- 
Rowan Tommins
[IMSoP]