Hi,
Thanks for that reply. Which
documents Annex B were you refering to?
Let us now assume that there are
no tag collissions (it just requires change of type associated with each field)
and hence no need for the decision of automatic (it just would not matter). But
why the inconsistency that when the CHOICE has RootComponentTypeList alone it
aint sorted, and when an extension is used the RootComponentList is sorted
before the type-checking. I understood from the ASN.1 semantic model (given in
the book by Olivier Dubuisson) that the decision of tagging is dont post
transformation that I mentioned. In case there is any other document that I
could refer to then kindly provide the link for the same. Pls observe the
following anomaly that should not have been there even ommiting the above
misunderstandings of mine -
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Choice1 ::=
CHOICE
{
f1 INTEGER,
f2 REAL
}
{
f1 INTEGER,
f2 REAL
}
Choice2 ::=
CHOICE
{
f2 REAL,
f1 INTEGER
}
{
f2 REAL,
f1 INTEGER
}
choice1 Choice1 ::= f1:10
choice2 Choice2 ::= choice1
--value not suitable for
Choice2--
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
ExtChoice1 ::= CHOICE
{
field1 INTEGER,
field2 INTEGER,
...,
field3 REAL,
field4 INTEGER
}
{
field1 INTEGER,
field2 INTEGER,
...,
field3 REAL,
field4 INTEGER
}
ExtChoice2 ::= CHOICE
{
field2 INTEGER,
field1 INTEGER,
...,
field3 REAL,
field4 INTEGER
}
{
field2 INTEGER,
field1 INTEGER,
...,
field3 REAL,
field4 INTEGER
}
ExtChoice3 ::= CHOICE
{
field1 INTEGER,
field2 INTEGER,
...,
field4 INTEGER,
field3 REAL
}
{
field1 INTEGER,
field2 INTEGER,
...,
field4 INTEGER,
field3 REAL
}
ext-choice1 ExtChoice1 ::= field2:10
ext-choice2 ExtChoice2 ::=
ext-choice1 -- Value is suitable
for ExtChoice2 --
ext-choice3 ExtChoice3 ::=
ext-choice1 -- Value not suitable
for ExtChoice3
--
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
As we can observe the sorting is
dont only if an extension marker is used. Why this anomaly? Thanking
you.
Yours Sincerely
Ram
----- Original Message -----
From: "Paul Thorpe" <[EMAIL PROTECTED]>
To: "Ramaswamy" <[EMAIL PROTECTED]>
Cc: "Geoffrey Elgey" <[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>
Sent: Tuesday, June 24, 2003 9:18 AM
Subject: Re: [ASN.1] Choice Type
>
> Please note that Annex B is purely for saying which types are compatible
> so that a value of one type can be used as a value of some other type.
> This annex does NOT specify that these transformations must be done before
> you decide how automatic tagging should be done for determining how to
> encode or decode values of a type. That is spelled out in the SET,
> SEQUENCE and CHOICE clauses in the main body of X.680 and is based purely
> on the textual order of the components in them.
>
> ----------------------------------------------------------------------------
> Paul E. Thorpe Toll Free : 1-888-OSS-ASN1
> OSS Nokalva International: 1-732-302-0750
> Email: [EMAIL PROTECTED] Tech Support : 1-732-302-9669
> http://www.oss.com Fax : 1-732-302-0023
