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Date: Fri, 18 Mar 2022 10:46:15 +0000
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Subject: Re: [PHP-DEV] Convert return to expression like throw
From: rowan.collins@gmail.com (Rowan Tommins)

On 18/03/2022 10:18, Florian Stascheck wrote:
> function getUnreadDocuments(): int {
> $documents = Auth::user()?->getDocuments() ?? return 0;
> // actual logic of the function
> return 42;
> }


I think I'd probably reject that example as too cryptic in a code 
review; the mixture of assignment and control flow is hard to follow, 
even more so than this, which is already possible:

if ( ! $documents = Auth::user()?->getDocuments() ) return 0;

I can imagine some people would like it, though, particularly those used 
to the Perl "doSomething() or die;" idiom.


The throw expression has uses in things like lambdas and match 
expressions, which only accept expressions not statements. I can't think 
of any examples where "return" would be useful in such contexts, and in 
fact wonder what they'd even do:

return $foo = match(1) { default => return 42; }

$foo = fn() => return 42;

function foo() { return return 42; }  // presumably you could stack this 
endlessly, "return return return return 42;"

function foo() { yield return 42; }

Throwing exceptions already aborts the control flow, so doing so in the 
middle of an expression is easy to understand; having an early return in 
the middle of an expression is harder to understand.

Regards,

-- 
Rowan Tommins
[IMSoP]