1047Re: JSON syntax grammar is missing 'undefined' literal value
- May 25, 2008Douglas Crockford wrote:
>Wow, thanks for the quick reply. Other than the legacy issue I
> JSON was intended to be language independent. Most languages have or
> the idea of a null value. Very few languages have two of them.
pointed out in my prior message, could I perhaps change your mind?
Afaics, neither C or C++ have a null datatype (C also no bool).
Either must tag all values with an enum(eration) of value types, or
use (void*)0 for null. Enum tagging could handle another datatype, or
use (void**)0. Classes in C++ don't help, because there is no typeof.
Or perhaps could use operator overloading in C++ with a class to
detect instances of that class.
It seems most all languages either fall into the above scenario of
simulating null (and thus could simulate undefined), or the modern
non-prototype 00 languges have a means for detecting the class of an
object, so then use new Undefined(). Afaik, even Java's Null type is
just a class.
I am working on an implicit schema for JSON (to enable Web 3.0
decentralized mashups) and I am thinking of declaring undefined to be
a legal value and usurp your defacto standard. Could you please steer
me otherwise with further logic?
Again thanks a lot for the feedback.
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