[Oberon] RE: PIC (was Re. Staapl)
Chris Glur
easlab at absamail.co.za
Tue Jul 29 05:23:33 MEST 2008
> >
> > The whole ideas of pic: minimal dil-devices; seems to
> > have morphed to absurdity - like upgrading a
> > wheel-barrow to a locomotive !
> >
Chris Burrows wrote:-
> Not for everybody - read about Wirth's recent PIC-related work here:
>
> http://www.inf.ethz.ch/personal/wirth/Articles/Miscellaneous/index.html
Wow ! The value of serendipit/dy.
This thread only got here because I wrongly failed to update my
EditKeys.Definitions ^ 's
default field from oberon at lists.inf.ethz.ch
Yes, Wirth has stuck with the original small DIL version.
I hope I can still buy them.
Usually they start with a '2 cylinder version' and later you can only
buy the '8 cylinder version'.
It's beautiful how Wirth has used eg.
!x.4 == set bit 4 of variable x
!~s.3 == clear bit 3 of variable s
?~B.6 == wait for bit 6 of [variable B eg.] the acknowledgement-signal
Compare this snappy syntax to the 'set-based' nightmare of x86-native.
OTOH I'm confused that he writes: ----------
> Conditional statements have the form shown at the left and explained in
> terms of conventional notation to the right.
>
> [cond -> StatSeq] IF cond THEN Statseq END
> [cond -> StatSeq0 |* StatSeq1 ] IF cond THEN Statseq0 ELSE StatSeq1 END
> [cond0 -> StatSeq0 | cond1 -> StatSeq1]
> IF cond0 THEN Statseq0 ELSIF cond1 THEN StatSeq1END
>
> Repetitive statements have the form:
>
> {cond -> StatSeq} WHILE cond DO Statseq END
> {cond0 -> StatSeq0 | cond1 -> StatSeq1}
> WHILE cond0 DO Statseq0 ELSIF cond1 DO StatSeq1 END
-------------
Which syntax WE don't like as much as OUR familiar:
> MODULE Conditions;
> INT x, y, z, w; SET s; BOOL b;
> BEGIN
> IF x = y THEN z := 0 END ;
> IF x = y & y # z & z >= w THEN z := 0 END ;
> IF x < y OR y <= z OR z > w THEN z := 0 END
> END Conditions.
---------------
which he writes in his same *.pdf explanation.
Aubrey.McIntosh wrote:
]Interesting. Has anyone downloaded the compiler?
No I can't find it even with:
http://www.google.com/search?submit=Google+Search&q=PICL
+site:www.inf.ethz.ch
If someone points me to the compiler, I'll do a simplified
report-back on some compile-test runs, because I've got the
hardware here.
Thanks.
== Chris Glur
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