Re: [RFC] Type hints

At 06:39 PM 5/2/2004 +0200, Timm Friebe wrote:

On Sat, 2004-05-01 at 22:09, Marcus Boerger wrote: Hello internals, while working with php 5 the last days i find it more and more annoying that we allow NULL with type hints. From my perspective allowing NULL with typehints would happen only very rare. I don't think this is true. I think there are a number of cases where passing NULL is used to "unset" or "delete" something. For example, say a class supports debugging using a listener model: class Foo {

    function setEventListener(Listener $l) { ... }

} $foo= new Foo(); $foo->setEventListener(new ConsoleListener()); // ... $foo->setEventListener(NULL); This makes perfect sense to me and also gets rid of the constraint of having to define an "unsetEventListener" method. To wrap it up: Would you agree that being able to pass NULL to any pointer argument in C is annoying?

Personally, I would leave things the way they are today. But both Zeev and Marcus feel this is the wrong way to go and I understand their point.

[...] 2) (Andi) introduce 'not null' after php 5.0. This won't introduce a BC break. But it would require two new keywords 'NOT' and 'NULL'. The latter is not a problem because it is a define at the moment and the patch (a) shows that it easy to change it into a keyword. The problem is the new keyword 'not' which would introduce a BC break for everyone using the word 'not' already. I like this idea best: No magic such as "only when it is the first default argument" (the question "why" will inevitably come up sooner or later); plus no BC break. Concerning the new keyword argument, how about using the exclamation mark (already meaning "not"), as in: * function foo(Classname !NULL $val) { } The same as Andi's suggestion, but using ! instead of "not" * function foo(Classname $val !NULL) { } Ditto, but using postfix notation. Comes close to default value syntax which people are already used to. * function foo(Classname $val != NULL) { } This would be even more similar to the default value syntax.

I prefer "not null" :) Andi