Re: [RFC] Void Return Type (v0.2, reöp ening)

Hi Larry, Larry Garfield wrote:

On 10/14/2015 06:30 PM, Andrea Faulds wrote:

This would be strange. The manual doesn't say null, and I can't think of any language which uses null as the return type in this situation, even when they have the same implicit-null-return behaviour that PHP has (see the email you're replying to). Also, wouldn't you expect this to behave like existing type hints, and let you return a null value from any source? But that's not what you would actually want, right? Thanks.

Well, that depends on the intent here. In practice, is the intent to add a "no return at all" type of function (ie, $a = foo() is a syntax error now where it was not before), or to make it explicit that the only legal return is null (even if implicitly that means having a non-early return statement is pointless)? Those are the two options. That may or may not dictate the keyword that gets used.

It would seem ideal to have "true" void functions which can't be used as expressions, i.e. producing an error if you try to use them like in your example. But they'd cause a backwards-compatibility headache, and I'm not sure they're a good idea anyway. Every function call being an expression is pretty handy. You can safely capture the return value of a callback and pass it along, for instance. In a sense, what this RFC offers might be called a compromise. It enforces the rules of void within the function, but at the end of the day the caller still gets a null out of it since that's what PHP's always done.

It definitely sounds like you're favoring the second (as that's what the RFC says). Which may or make not make "void" an odd keyword to choose when what's actually happening is NULL getting returned. Is NULL a void? (There's a deep philosophical question...)

It's an interesting question. There's some precedent for using void in this way even though the functions aren't "truly" void. I mostly like void because it's the customary keyword to use, though. Everyone knows what a 'void function' is.

As I said, I don't have a strong opinion on the subject yet. I'm just trying to distil the discussion down to as small a question as possible. :-)

I appreciate your efforts. I have a tendency to be a bit verbose in my writing, so providing clarity is helpful. :) Thanks. -- Andrea Faulds http://ajf.me/