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
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