RE: [sv-bc] Aggregate expressions

I agree with Shalom.  The LRM is clear that a "data object" is a named
entity.  That name can be used as an expression.  Evaluating that
expression yields the current value of the data object.

For example, in

     var automatic integer N = 5;
     N = N + 1;

the data object is a variable named N.  On entry to the scope the data
object is created and initialized to the integer 5.  Then the expression
"N" is evaluated, yielding its value, which is the integer 5.  That
value and the integer 1 are added, and the result integer 6 is assigned
to the data object.  The data object is still the integer variable, but
its value has changed.  On exit from the scope, the data object ceases
to exist.

The LRM is less clear whether a select of a data object is also a data
object. Is a field of a struct variable also a named entity?  How about
A[4:9]?  

-- Brad

   

-----Original Message-----
From: owner-sv-bc@eda.org [mailto:owner-sv-bc@eda.org] On Behalf Of
Bresticker, Shalom
Sent: Wednesday, March 05, 2008 12:19 AM
To: Rich, Dave
Cc: sv-bc
Subject: RE: [sv-bc] Aggregate expressions

Those are called 'objects' or 'class objects', not 'data objects'.

Shalom 

> -----Original Message-----
> From: Rich, Dave [mailto:Dave_Rich@mentor.com]
> Sent: Wednesday, March 05, 2008 10:14 AM
> To: Bresticker, Shalom; Greg Jaxon
> Cc: sv-bc
> Subject: RE: [sv-bc] Aggregate expressions
> 
> That sentence does not preclude a data object from being other things.
> In fact, the construction of a class is an object that does not have a

> name.
> 
> Dave
> 
> 
> > -----Original Message-----
> > From: Bresticker, Shalom [mailto:shalom.bresticker@intel.com]
> > Sent: Tuesday, March 04, 2008 11:57 PM
> > To: Rich, Dave; Greg Jaxon
> > Cc: sv-bc
> > Subject: RE: [sv-bc] Aggregate expressions
> > 
> > A data object is not defined that in the LRM. 6.2 says,
> > 
> > "A data object is a named entity that has a data value
> associated with
> > it, such as a parameter, a variable, or a net."
> > 
> > And the LRM consistently uses 'data object' with that meaning. You
> can't
> > change its meaning in a single place.
> > 
> > Shalom
> > 
> > > -----Original Message-----
> > > From: owner-sv-bc@server.eda.org
> > > [mailto:owner-sv-bc@server.eda.org] On Behalf Of Rich, Dave
> > > Sent: Wednesday, March 05, 2008 9:46 AM
> > > To: Bresticker, Shalom; Greg Jaxon
> > > Cc: sv-bc
> > > Subject: RE: [sv-bc] Aggregate expressions
> > >
> > > It sure is - essentially it's an anonymous variable.
> > >
> > > > -----Original Message-----
> > > > From: owner-sv-bc@server.eda.org
> [mailto:owner-sv-bc@server.eda.org]
> > > On
> > > > Behalf Of Bresticker, Shalom
> > > > Sent: Tuesday, March 04, 2008 11:31 PM
> > > > To: Greg Jaxon
> > > > Cc: sv-bc
> > > > Subject: RE: [sv-bc] Aggregate expressions
> > > >
> > > > But an assignment pattern is not a data object.
> > > >
> > > > Shalom
> > > >
> > > > > -----Original Message-----
> > > > > From: Greg Jaxon [mailto:Greg.Jaxon@synopsys.com]
> > > > > Sent: Tuesday, March 04, 2008 6:14 PM
> > > > >
> > > > > How about?
> > > > >
> > > > > "Unpacked structure and array data objects, including those 
> > > > > constructed using assignment patterns, can be combined into 
> > > > > aggregate expressions."
> > > > >
> > > > > The paragraph that follows /is/ sort of a hodge podge.
> > > > > Sentences seems to just be throwing some things into
> the pot of
> > > > > "unpacked data object"
> > > > > and others throw operators like equality into the pot of
> > > aggregate
> > > > > expression.
> > > > > I agree that ?: is an aggregate expression operator.
> > > > >
> > > > > We're a long way from thinking of this as a first class array 
> > > > > language.
> > > > >
> > > > > Greg
> > > > >
> > > > > Bresticker, Shalom wrote:
> > > > > > Does anyone object to the editor replacing
> 'constructors' with
> > > > > > 'assignment patterns'?
> > > > > --------------------------------------------------------------
> > > > > >     *From:* owner-sv-bc@server.eda.org
> > > > > >     [mailto:owner-sv-bc@server.eda.org] *On Behalf Of
> > > > > *Bresticker, Shalom
> > > > > >     *Sent:* Thursday, February 28, 2008 12:20 PM
> > > > > >
> > > > > >     I also don't think the term 'aggregate expression' is
> > > > > well defined.
> > > > > >
> > > > > >     I also don't think the first sentence makes sense:
> > > > > >     "Unpacked structure and array data objects, as well as
> > > unpacked
> > > > > >     structure and array constructors, can all be used
> > > as aggregate
> > > > > >     expressions."
> > > > > >
> > > > > >     What is meant by "unpacked structure and array
> > > > > constructors," which
> > > > > >     are different from data objects?
> > > > > >
> > > > > >     The version of this sentence in SV 3.1a is,
> > > > > >
> > > > > >     "Unpacked structure and array variables, literals, and
> > > > > expressions
> > > > > >     can all be used as aggregate expressions."
> > > > > >
> > > > > >     So "literals and expressions" are contrasted to
> "variables".
> > > In
> > > > > >     1800, we still have structure and array "literals". But
> what
> > > are
> > > > > >     called structure and array "expressions" in
> 3.1a, are now
> > > called
> > > > > >     "assignment patterns". Since structure and array
> > > > > literals are a form
> > > > > >     of assignment patterns, I think "constructors" in
> > > the sentence
> > > > > >     should be replaced with "assignment patterns".
> > > > > >
> > > > > >     Shalom
> > > > >
> > >
> ----------------------------------------------------------------------
> > > > \
> > > > > >          *From:* owner-sv-bc@server.eda.org
> > > > > >         [mailto:owner-sv-bc@server.eda.org] *On Behalf Of
> > > > > *Bresticker,
> > > > > >         Shalom
> > > > > >         *Sent:* Thursday, February 28, 2008 11:47 AM
> > > > > >
> > > > > >         I don't think this paragraph was intended to be a
> > > > > complete list.
> > > > > >
> > > > > >         Shalom
> > > > > --------------------------------------------------------------
> > > > > >             *From:* owner-sv-bc@server.eda.org
> > > > > >             [mailto:owner-sv-bc@server.eda.org] *On Behalf
> > > > > Of *danielm
> > > > > >             *Sent:* Thursday, February 28, 2008 11:40 AM
> > > > > >
> > > > > >             1800-2005 states :
> > > > > >             Unpacked structure and array data objects,
> > > as well as
> > > > > >             unpacked structure and array constructors, can
> > > > > all be used
> > > > > >             as aggregate expressions. A multi-element
> > > slice of an
> > > > > >             unpacked array can also be used as an aggregate
> > > > > expression.
> > > > > >             Aggregate expressions can be copied in an
> > > assignment,
> > > > > >             through a port, or as an argument to a task or
> > > function.
> > > > > >             Aggregate expressions can also be compared with
> > > > > equality or
> > > > > >             inequality operators. To be copied or compared,
> > > > > the type of
> > > > > >             an aggregate expression must be equivalent.
> > > See 6.9.2.
> > > > > >             IMHO there is more expression when aggregate
> > > > > expression are
> > > > > >             sensible i.e: conditional operator
> (?:), function
> > > return
> > > > > >             value. Maybe there are more?
> > > > > >
> > > > > >             Will 1800-2005 add some operators to this
> > > description?
> > > > > >
> > > > > >             DANiel
> > > >
> > >
> ---------------------------------------------------------------------
> > > > Intel Israel (74) Limited
> > > >
> > > > This e-mail and any attachments may contain confidential
> > > material for
> > > > the sole use of the intended recipient(s). Any review or
> > > distribution
> > > > by others is strictly prohibited. If you are not the intended 
> > > > recipient, please contact the sender and delete all copies.
> > > >
> > > >
> > > > --
> > > > This message has been scanned for viruses and dangerous
> content by
> > > > MailScanner, and is believed to be clean.
> > > >
> > >
> > >
> > > --
> > > This message has been scanned for viruses and dangerous
> content by
> > > MailScanner, and is believed to be clean.
> > >
> > >
> > >
> > 
> ---------------------------------------------------------------------
> > Intel Israel (74) Limited
> > 
> > This e-mail and any attachments may contain confidential
> material for
> > the sole use of the intended recipient(s). Any review or
> distribution
> > by others is strictly prohibited. If you are not the intended 
> > recipient, please contact the sender and delete all copies.
> 
> 
---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution by
others is strictly prohibited. If you are not the intended recipient,
please contact the sender and delete all copies.


--
This message has been scanned for viruses and dangerous content by
MailScanner, and is believed to be clean.



-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.