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Date: Thu, 11 Mar 2021 08:37:52 +0500
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Subject: Honour the Default Value of 'return' Statement According to the Function Signature
From: office.hamzaahmad@gmail.com

Hello Internals,
I congratulate you for the successful release of PHP 8.0.3. I also
appreciate your efforts to bring union types and return type hints.
Although the type hints have made debugging more easier, it has created
another problem for those that use 'return' to end the execution of a
function or method call.
There are mainly two usages of 'return'. First ends the execution of the
remaining statements. Second returns a value. The return type hints aids
with the second usage and ignores the former facility. In other words, if
one wants to avoid large code blocks i.e. the conditional blocks, it can
write like following.

<?php
function foo()
{
	If (true /*condition1*/)
		return;

	if (!false /*condition2*/)
		return;

	/*the remaining part of a function*/
};
?>

The above function returns null if conditions are met. Otherwise, it returns
no value. It was okay when there was no concept of return type hints. When
return types have been introduced, the behaviour needs to be evolved, too.
What if the return type was set 'int|float' in the above example? The
compiler would give following error:
Fatal error: A function with return type must return a value.... Similarly,
a function with ': void' signature produceed that a function may not return
a value.
To resolve such a problem, I request to honour the function signature when
you evaluate return statements. Instead of looking for no 'return'
statements in ': void' functions, verify whether a function specifies a
return value. If the function returns a type other than the types declared
in the signature, it may produce wrong type error. If a function with void
returns a value i.e. contains a non-empty return (return;) statement, the
compiler may throw an error stating that a function with void signature must
not return a value.
Likewise, 'return' may return an empty array if the return type was set to
array; the similar case applies to string, int, float, object etcetera. In
the case of ': void' signature, 'return' only ends the execution and returns
no value.
PHP also allows to specify only returning 'false' from a function call. What
if you extend this functionality and allow specifying literals including
null? If nulls are also allowed, the backword behaviour could be
impleamented. For example:
public function foo() : string| null;

Consider the following example for literals.
<?php
function get_nationality_string(int $country_code) : string | "unknown"
{
	return;
};
?>

I am positive that you will consider my request and provide me with the
feedback in case of any inconsistency in my argument. I wish you best of
luck for the on-going work for the PHP 8.1.
Best Regards
Hamza Ahmad