On Tue, 24 Jun 2003, Ramaswamy wrote:
> Hi,
> Thanks for that reply. Which documents Annex B were you refering to?
X.680 Annex B.
>
> 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 -
This looks like a bug in the tool you are using to do the checking.
Paul
>
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> Choice1 ::= CHOICE
> {
> f1 INTEGER,
> f2 REAL
> }
>
> Choice2 ::= CHOICE
> {
> 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
> }
>
> ExtChoice2 ::= CHOICE
> {
> field2 INTEGER,
> field1 INTEGER,
> ...,
> field3 REAL,
> field4 INTEGER
> }
>
> ExtChoice3 ::= CHOICE
> {
> 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
>
>
> > Hi Ramaswamy,
> >
> > 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
>
