Re: [Fwd: from [David Bishop <dbishop@server.vhdl.org>]]

Subject: Re: [Fwd: from [David Bishop ]]
From: John Michael Williams (jwill@AstraGate.net)
Date: Thu Dec 12 2002 - 09:57:35 PST

Hi All.

I think it would be a serious error to add functions of
the same name (and signature) to more than one package.

It seems a bit bizarre that two WG's would be
in sort of a competition to add functions to their
packages. Something should be worked out so
that the PURPOSE of the new function would determine
the package in which it was located.

If there is a logic-state meaning, 1164 should
add the function; if there is a computational
meaning, numeric-std.

It isn't much of a bother to USE a package just to get
one function; it would be a problem if the tool(s) involved
couldn't handle anything but USE (package_name).ALL,
and this resulted in exposure of two functions
of the same name. 

-- 
                         John
                     jwill@AstraGate.net
                     John Michael Williams

Peter Ashenden wrote:
> 
> -----Forwarded Message-----
> 
> Date: Sat, 07 Dec 2002 10:06:08 -0500
> From: David Bishop <dbishop@server.vhdl.org>
> To: Jim Lewis <jim@synthworks.com>
> CC: Std_Logic 1164 <vhdl-std-logic@server.eda.org>,
>    "Numeric_Std 1076.3" <vhdlsynth@server.eda.org>
> Subject: Re: std_logic_1164: CP-010 and numeric_std:Rob_P1
> References: <3DF15D9F.5050804@SynthWorks.com>
> Content-Type: text/plain; charset=us-ascii
> Content-Transfer-Encoding: 7bit
> 
> Jim Lewis wrote:
> >
> > CP-010  Analyzed    Add match functions like numeric_std.std_match
> > http://www.eda.org/vhdl-std-logic/proposals/CP-010-match-functions.txt
> 
> If a command called "match" is added to "std_logic_1164" then
> we should add one to "numeric_std" for "unsigned" and "signed".
> 
> Thus I propose:
>   function MATCH (L, R: UNSIGNED) return BOOLEAN;
>   -- Result subtype: BOOLEAN
>   -- Result: terms compared per STD_LOGIC_1164 intent
> 
>   function MATCH (L, R: SIGNED) return BOOLEAN;
>   -- Result subtype: BOOLEAN
>   -- Result: terms compared per STD_LOGIC_1164 intent
> 
> These should simply call the "std_match" function which we
> already have.
> 
> > In numeric_std, it was proposed in proposal Rob_P1/P2
> > (http://www.eda.org/vhdlsynth/pilot/hm/0026.html), that
> > the std_match functions for std_ulogic, std_logic_vector, and
> > std_ulogic_vector be moved to std_logic_1164.
> 
> As already stated, we can't remove them.  That would make lots
> of code obsolete.  But we can create new ones.
> 
> We have to consider the possibility of that the new "numeric_std"
> package and the new "std_logic_1164" packages will not be released
> at the same time.
> 
> > This would satisify CP-010 and Rob_P2.  Is this a move that
> > everyone would support?  Otherwise, CP-010 proposes adding a match
> > function to std_logic_1164.  This means that we should add a
> > match function to numeric_std.  There is more meaning to a
> > function when it is globally used.
> 
> I agree as stated above.
> 
> --
> NAME:     David W. Bishop           INTERNET: dbishop@vhdl.org

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