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Date: Thu, 15 Oct 2015 16:32:16 +0100
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Subject: =?UTF-8?Q?Re:_[PHP-DEV]_[RFC]_Void_Return_Type_=28v0.2=2c_re=c3=b6p?=
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From: ajf@ajf.me (Andrea Faulds)

Hi Rowan,

Rowan Collins wrote:
> I can see the point in denying the right to say "return
> some_function_expected_to_return_null();" But in a sense this is no
> different from declaring that a function returns int, and then writing
> "return some_function_expected_to_return_int();"
>
> If a void function can be used in an expression, it can be used in a
> return expression, and if so, it feels natural for the type hint to
> propagate:
>
> function foo(): void { do_something(); }
> function wrapped_foo(): void { do_something_else(); return foo(); }
> // ERROR: can't specify return value in a void function
>
> "return foo()" is not illegal because foo is declared void, but because
> wrapped_foo is - even though the result is exactly as expected.

Hmm, this is an interesting case you've pointed out. Being able to do 
`return some_other_void_function();` is something I've desired in other 
languages.

But what if that void function you're calling later adds a return value? 
Now the calling function is returning a value other than null, violating 
its type hint and producing a runtime error.

It's a shame there's no "tail call this other function and discard its 
result" construct.

Thanks.


-- 
Andrea Faulds
http://ajf.me/