RE: [sv-ac] RE: feedback on 1758, -> and <-> operators

Hi John,

good point. I'd say that the boolean implication would have precedence
and so it should be interpreted as (a->b) and c. But... would it be more
useful if it were a -> (b and c) ?

In either case, some explanation should / will be added. In Section 17
where the operator is introduced on properties.

regards,
ed

> -----Original Message-----
> From: John Havlicek [mailto:john.havlicek@freescale.com] 
> Sent: Thursday, April 12, 2007 3:29 PM
> To: Eduard.Cerny@synopsys.COM
> Cc: piper@cadence.com; Eduard.Cerny@synopsys.COM; sv-ac@eda.org
> Subject: Re: [sv-ac] RE: feedback on 1758, -> and <-> operators
> 
> Hi Ed:
> 
> In 1800-2005, weren't all the HDL operators in Section 8 of higher 
> precedence than the sequence and property opertors from Section 17?
> 
> I like the syntax "->", "<->", but isn't there a problem with the
> operator precedence that needs to be explained?
> 
> E.g., if I have
> 
>   logic a,b,c;
> 
>   assert property (a -> b and c);
> 
> what do I get?  
> 
> J.H.
> 
> > 
> > ------_=_NextPart_001_01C77AC4.D6FCA3E0
> > Content-Type: text/plain;
> > 	charset="us-ascii"
> > Content-Transfer-Encoding: quoted-printable
> > 
> > Hello Lisa,
> > =20
> > The change in 8.2 is in the addition of -> and <-> in 
> binary_operator.
> > =20
> > Regarding the arguments to the operators: the operators -> 
> and <-> are
> > overloaded, so that in Clause 8 it talks about expressions 
> only. Hence !
> > etc. are correct. In Clause 17 it is a property operator.
> > =20
> > Yes, property_expr is also sequence_expr.
> > =20
> > Hope it explains the intent of the proposal.
> > =20
> > Best regards,
> > ed
> > =20
> > 
> > 
> > ________________________________
> > 
> > 	From: Lisa Piper [mailto:piper@cadence.com]=20
> > 	Sent: Sunday, April 08, 2007 6:16 PM
> > 	To: Eduard Cerny
> > 	Cc: sv-ac@eda.org
> > 	Subject: feedback on 1758, -> and <-> operators
> > =09
> > =09
> > 
> > 	Hi Ed,
> > 
> > =09=20
> > 
> > 	I read the 1758 proposal.  I cannot tell where the change is in
> > section 8.2.  They look the same.
> > 
> > =09=20
> > 
> > 	My understanding from 17.11 is that it must be a property_expr
> > on both sides of these operators. If so, then the text to 
> insert between
> > 8-1 and Table 8-1 is wrong. It should use not instead of 
> "!" and and/or
> > instead of && and //.  But then other places it looks like 
> it can be a
> > sequence expression.  Perhaps this is because a sequence expr is a
> > property expr?  I'm confused.
> > 
> > =09=20
> > 
> > 	Lisa
> > 
> > =09=20
> > 
> > =09=20
> > 
> > 
> 

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