[Home] [By Thread] [By Date] [Recent Entries]


On Monday 09 December 2002 18:49, Sean McGrath wrote:

> 2. The amount of concrete shared datatypes that can be enshrined
> without getting into platform/application specific datatypes is
> low.

I would disagree; the set of datatypes in ASN.1 was designed to be platform 
independent.

I mean, the concept of an integer is platform independent. A 32-bit signed 
integer like 'int' is getting a bit platform specific, although most 
platforms can manage that these days.

So in ASN.1 you don't have types like 'int' 'long' 'double' and so on, you 
have types like INTEGER which is an arbitrary precision integer. You can 
limit it to a fixed range if you want, but there is no inbuilt 'integer 
between the seemingly arbitrary -2^31-1 and +2^31'. For floating point you 
specify how many digits or bits (you choose) of exponent and mantissa you 
want, but without limits they are arbitrary length.

By 'arbitrary length' we mean the same way that strings are arbitrary length, 
mmmkay? And before anyone says that 'arbitrary length' won't be 
interoperable, it is interoperable as long as the recipient has enough memory 
to store them, and if that may be a problem then you specify limits in your 
schema; XML has the same situation with string types and entity expansion and 
so on, so don't knock 'arbitrary length'!

>
> regards,
> Sean
>

ABS

-- 
A city is like a large, complex, rabbit
 - ARP

Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member