Re: Priority revisited: a new primitive

[A E Lawrence <adrian.lawrence@xxxxxxxxxxxxx>]

"Gerald H. Hilderink" wrote:

> > is just
> >
> > ALT
> >   c ? x & d ? y
> >     blah
> >
> > if you intrepret "&" as merge. In other words, just omit the M (!).
> 
> Yes, the MALT is the same as the ALT with the event merge symbol (diamond
> operator).
> 
> > I wrote \merge as \diamond in my LaTex syntax for no very good reason,
> > and then used <> to match in ACSII. Either we overload <> or &. I don't
> > think either case leads to any ambiguity. & has the advantage of a
> > single keystroke.
> 
> Doesn't symbol & confuse with conditional guards and with merging events, as
> in,
> 
> ALT
>   cond & event1 & event2
> 
> or is
> 
> ALT
>   cond & event1 <> event2

Given that the syntax can always(?) tell a boolean from an event, I
think that either are acceptable. It is precisely because & is used in
conditional guards that I quite liked your "&". My choice of \diamond in
LaTeX was really because I was looking for an unused simple standard
symbol that suggested a binary infix operator, and various variants of
\diamond fitted that. And the natural ASCII version was <> with the
unfortunate consequence of coinciding with not_equal_to. 

I have no strong feelings about the matter, but rather favour your "&"
because it has a more natural interpretation, and is a single keystroke.
I'm not sure that I would want to use & in typeset versions because of
its other connotations, but maybe even there it might be a good idea.

I was about to say that this isn't really important, but on reflection,
the choice of clean apposite notation is crucial. If we copy this to the
list, any better suggestions are welcome.

> >
> > The point about "merged" events is that they can occur anywhere, not
> > just in the guards of (M)ALTs. And we need them for other reasons,
> > especially in hardware compilation. Which is why I think MALT should be
> > suppressed before it gets a hold. KISS !

I keep meaning to point out the equivalence [is it formal ? :-) ]:-
 
      KISS = occam's razor = principle of maximum entropy (Jaynes) 

If you like you can send our exchange of thoughts to the list.

Adrian
-- 
Dr A E Lawrence (from home)