>> The datatypes groups voted to disallow <nettype> followed by 'reg' as a
>> lexical restriction.
>
>I cannot find this restriction anyplace in the proposed BNF, chapter 4 or 5
>changes to the LRM.
>
>Is it an oversight that this was left out?
>
>How exactly was this restriction formulated?
I was asked to check with Brad Pierce about where it should appear, since
the BNF was one possibility. Brad expressed the opinion that it should
appear in the text instead. The best place would probably be the new
sub-section in section 5 on nets. It would be nice if the syntax boxes
were broken up so that the syntax for variable declarations appeared in
the sub-section on variables, and the syntax for net declarations appeared
in the sub-section on nets. Then the syntax would be right there and the
restriction could appear in the text after it.
The restriction is supposed to be against having the net_type token
immediately followed by the "reg" token. An alternate restriction that
the group considered was just disallowing "tri" followed by "reg". Enough
people felt that constructs like "wire reg" were also confusing, that once
the restriction was made, it might as well be broadened.
While this combination could have been prevented grammatically, it would
have required some hideously messy changes in the BNF. It was deemed
easier to express it as a separate lexical restriction against having
this sequence of tokens. It isn't pretty, but nobody came up with a
suggestion that people liked better.
Steven Sharp
sharp@cadence.com
Received on Wed Nov 10 15:42:15 2004
This archive was generated by hypermail 2.1.8 : Wed Nov 10 2004 - 15:42:18 PST