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From: "Brian L. Stuart" <blstuart@bellsouth.net>
To: tuhs@minnie.tuhs.org, "Michael Kjörling" <michael@kjorling.se>
Subject: Re: [TUHS] v7 K&R C
Date: Sat, 25 Apr 2020 21:34:44 +0000 (UTC)	[thread overview]
Message-ID: <1862444098.192050.1587850484006@mail.yahoo.com> (raw)
In-Reply-To: <9900c104-6f80-4b35-ae53-08b95c9dfbdf@localhost>

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 On Saturday, April 25, 2020, 04:17:14 PM EDT, Michael Kjörling <michael@kjorling.se> wrote:
> I was thinking: couldn't we apply the same kind of reasoning to
> variables as well?
> ...

In short, yes. In the language Bliss, all identifiers
stood for the address of that thing. A prefix dot (.)
dereferences that thing. So copying x to y would be
something like

y = .x;

In C, rvalues have an implicit dereference happening.

I've actually created a toy language that I subject
my students to that revives the Bliss view to drive
home in their minds the difference between the
address of a memory location and the contents
of a memory location. I want them to have some
concept of how the program connects to the machine
before they find themselves so mired in abstraction
that everything is treated as magic.

One of my TAs in that class last fall was taking a
class in the winter where she was using C seriously
for the first time and having trouble understanding
pointers. When I explained how C pointers worked
in terms of the variables and dots of this other
language it became much more clear for her.

BLS
  

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  reply	other threads:[~2020-04-25 21:35 UTC|newest]

Thread overview: 141+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-25 13:11 Noel Chiappa
2020-04-25 13:18 ` Rob Pike
2020-04-25 14:57   ` Warner Losh
2020-04-25 16:13     ` [TUHS] C and C++ Regrets ron
2020-04-25 18:03   ` [TUHS] v7 K&R C Noel Chiappa
2020-04-25 20:11     ` Michael Kjörling
2020-04-25 21:27       ` Brian L. Stuart
2020-04-26  0:07     ` emanuel stiebler
2020-04-26  0:54     ` Rob Pike
2020-04-26 19:37     ` Derek Fawcus
2020-04-26 20:10       ` Derek Fawcus
2020-04-26 21:59         ` Rich Morin
2020-04-26 22:38         ` Noel Hunt
2020-04-26 23:57         ` Nemo Nusquam
2020-04-27  3:38           ` Rob Pike
2020-04-25 13:35 ` Hellwig Geisse
2020-04-25 13:59   ` Richard Salz
2020-04-25 19:01   ` Brian L. Stuart
2020-04-25 20:07     ` Michael Kjörling
2020-04-25 21:34       ` Brian L. Stuart [this message]
2020-04-26  6:40     ` arnold
2020-04-27 18:47       ` [TUHS] s-for-v7, was " Adam Thornton
  -- strict thread matches above, loose matches on Subject: below --
2020-05-19 12:29 [TUHS] " Noel Chiappa
2020-05-19  2:29 Doug McIlroy
2020-05-19  3:20 ` Steve Nickolas
2020-05-18 14:33 Doug McIlroy
2020-05-18 13:58 Doug McIlroy
2020-05-16 18:45 Richard Tobin
2020-05-16 21:55 ` Ronald Natalie
2020-05-16  0:15 Nelson H. F. Beebe
2020-05-16  0:28 ` Steffen Nurpmeso
2020-05-16  1:52 ` Warner Losh
2020-05-16 16:31   ` Paul Winalski
2020-05-16 20:35     ` Brad Spencer
2020-05-16 20:37       ` Warner Losh
2020-05-18 12:25     ` Tony Finch
2020-05-15 21:31 Richard Tobin
2020-05-15 21:53 ` Steve Nickolas
2020-05-15 22:33   ` ron
2020-05-15 23:34     ` Steffen Nurpmeso
2020-05-16  1:26       ` Larry McVoy
2020-05-16 21:59       ` Ronald Natalie
2020-05-16 23:26         ` Steffen Nurpmeso
2020-05-17 16:24           ` Paul Winalski
2020-05-17 16:29             ` ron
2020-05-17 16:38               ` Paul Winalski
2020-05-17 20:08                 ` Clem Cole
2020-05-18  8:46                   ` Peter Jeremy
2020-05-19  7:41                     ` Dave Horsfall
2020-05-18 12:04             ` Tony Finch
2020-05-18 13:10               ` Clem Cole
2020-05-18 15:13             ` Rich Morin
2020-05-18 15:51               ` Brantley Coile
2020-05-18 16:11             ` Dan Cross
2020-05-18 21:18               ` ron
2020-05-17 16:10 ` Derek Fawcus
2020-05-17 16:14   ` ron
2020-05-15 20:34 Doug McIlroy
2020-05-15 20:40 ` Warner Losh
2020-05-14 18:41 Doug McIlroy
2020-05-14 18:45 ` Richard Salz
2020-05-14 20:54 ` Clem Cole
2020-05-15  2:44 ` Rob Pike
2020-05-15  3:57   ` Rich Morin
2020-05-15  7:55   ` Dr Iain Maoileoin
2020-05-15 15:01     ` Larry McVoy
2020-05-15 15:36       ` John P. Linderman
2020-05-15 20:01         ` ron
2020-05-15 20:03           ` Larry McVoy
2020-05-15 20:05           ` Clem Cole
2020-05-15 20:18             ` ron
2020-05-15 20:24               ` Clem Cole
2020-05-16  0:57               ` Brantley Coile
2020-05-16 16:14                 ` Dan Cross
2020-05-15 20:56           ` Steve Nickolas
2020-05-16  0:31             ` Peter Jeremy
2020-05-16  8:30               ` Steve Nickolas
2020-05-16  0:43           ` John P. Linderman
2020-05-16 16:28             ` Paul Winalski
2020-05-16 17:39               ` Warner Losh
2020-05-19 19:45                 ` Peter Pentchev
2020-05-20  3:52                   ` Rich Morin
2020-05-21 15:06                     ` Dave Horsfall
     [not found] <mailman.1.1589421601.13778.tuhs@minnie.tuhs.org>
2020-05-14  3:02 ` Paul McJones
2020-05-14 17:08   ` Paul Winalski
2020-05-14 17:58     ` Clem Cole
2020-04-27 17:45 Noel Chiappa
2020-04-27 17:56 ` Richard Salz
2020-04-27 18:02 ` Brantley Coile
2020-04-27 18:47 ` Derek Fawcus
2020-04-25 19:41 Noel Chiappa
2020-04-25 20:27 ` Steffen Nurpmeso
2020-04-25  1:59 Adam Thornton
2020-04-25  2:37 ` Charles Anthony
2020-04-25  2:47   ` Adam Thornton
2020-04-25  2:51     ` Rob Pike
2020-04-25  2:54       ` Rob Pike
2020-04-25  3:04         ` Larry McVoy
2020-04-25  3:30           ` Clem Cole
2020-04-25  3:43             ` Larry McVoy
2020-04-25  3:54               ` Jon Steinhart
2020-04-25 11:44                 ` Michael Kjörling
2020-04-25 13:17             ` Dan Cross
2020-05-11  0:28         ` scj
2020-05-11  0:32           ` Rob Pike
2020-05-11  0:57             ` Larry McVoy
2020-05-11 17:32               ` Greg A. Woods
2020-05-11 18:25                 ` Paul Winalski
2020-05-11 18:37                   ` Clem Cole
2020-05-11 19:12                     ` Paul Winalski
2020-05-11 19:57                       ` joe mcguckin
2020-05-11 20:25                         ` Larry McVoy
2020-05-12 17:23                           ` Paul Winalski
2020-05-12 17:35                             ` ron
2020-05-12 17:42                               ` Larry McVoy
2020-05-12 18:36                               ` Paul Winalski
2020-05-13 23:36                             ` Dave Horsfall
2020-05-14  0:42                               ` John P. Linderman
2020-05-14  2:44                                 ` Rich Morin
2020-05-14  3:09                                   ` Charles Anthony
2020-05-14 12:27                                     ` ron
2020-05-14 12:27                                     ` ron
2020-05-14 12:27                                     ` ron
2020-05-14  7:38                                   ` Dave Horsfall
2020-05-14 12:25                                     ` ron
2020-05-14 17:13                                   ` Paul Winalski
2020-05-14 17:21                                 ` Larry McVoy
2020-05-17 16:34                                   ` Derek Fawcus
2020-05-14  4:21                               ` Greg A. Woods
2020-05-14  4:40                                 ` Warner Losh
2020-05-14 17:32                               ` Larry McVoy
2020-05-14 22:32                                 ` Tony Finch
2020-05-16 23:53                                   ` Steffen Nurpmeso
2020-05-17  0:35                                     ` Larry McVoy
2020-05-11 18:37                   ` Larry McVoy
2020-05-11  2:08           ` Lawrence Stewart
2020-05-11 11:36           ` Michael Kjörling
2020-04-25  3:37       ` Dave Horsfall
2020-04-27 13:19       ` Tony Finch
2020-04-25  2:50   ` Adam Thornton
2020-04-25  5:59     ` Lars Brinkhoff

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