Roy T. Fielding wrote:
The null type is just a language gimmick to bypass strong typing.
It does not exist in the data model.
That's ... interesting.
I am interesting what James Gosling will say on that, will definitely ask him
about.
Again, language gimmicks to bypass strong typing.
Null is a type and it is enforce strong typing.
> They have no relevance to JCR.
Could you please tell us what JCR is stand for ?
And how it has no relevance to Java ?
The fact that the symbol "null" can be converted to the data
value of zero in an integer context has no relevance to a data model.
What you passed is zero, not null.
First of all zero and null are 2 distinct values.
Variables don't exist in data models. Please, try to think of it terms
of data that is exchanged between two different computers that have
no shared memory. The language concepts that you are talking about
do not cross such a boundary and thus have no purpose in a data model.
In this particular discussion I think in terms of Java API !
But so far I can see anything else (C, Perl, etc) plus now it is an application
network layer.
Yes. Make the date field an optional property. If the property exists,
then the field is present. If not, then the field is absent.
Excellent, but how would user fill-up this `absent` field when we decide to?
Well, first, you haven't assigned the value null -- you just assigned
age a value of 0. The XML is showing it as an empty string (an empty
element has value = "") and you translate that to null (for no apparent
reason), convert that to a data value of Integer 0, and then assign it
to age. Writing that back out would be the same as if the value had
been given as <value>0</value>, which isn't the same thing unless we
assume application knowledge about infants not being in contacts.
There are at least two or three errors in that line alone.
A sane implementation would check the string value for
an integer and exclude the age property if the value is invalid.
There might be some argument for using null within the query
model as a synonym for "name doesn't exist". For example, instead
of checking for both ((name doesn't exist) or (name == default)),
it might be faster to check for (name == (null or default)).
Allowing null as a property value would prevent such a language
feature from being used within the query model.
I will rest my case here.
--
Ivan Latysh
[EMAIL PROTECTED]
