On Mon, Jul 20, 2009 at 9:54 PM, Paul Rubinhttp://phr...@nospam.invalid wrote:
Simon Forman sajmik...@gmail.com writes:
But I'm glad it's there to study, these are wheels I don't have to
invent for myself.
http://dwheeler.com/essays/high-assurance-floss.html
might be an interesting place to
Simon Forman wrote:
My understanding (so far) is that you (hope to) /derive/ correct code
using formal logic, rather than writing code and then proving its
soundness.
But to the extent you can rigorously formalise it,
all you've done is create Yet Another Programming
Language.
Which is fine,
greg g...@cosc.canterbury.ac.nz writes:
However, I suspect that you can't improve much on what we've already
got without restricting the domain of applicability of the
language. Otherwise, you just shift the intellectual bottleneck from
writing a correct program to writing correct
Calroc wrote:
It may be that flawless software is an unreachable asymptote, like the
speed of light for matter, but I'm (recently!) convinced that it's a
goal worthy of exploration and effort.
Seems to me that once you get beyond the toy program
stage and try to apply correctness proving to
On Jul 19, 2:51 pm, Paul Rubin http://phr...@nospam.invalid wrote:
Calroc forman.si...@gmail.com writes:
I'm engaged presently in starting a school to teach programming from
the ground up, based roughly on the curriculum outlined in the article
I mentioned. ...
I'm excited about formal
On Jul 20, 4:00 am, greg g...@cosc.canterbury.ac.nz wrote:
Calroc wrote:
It may be that flawless software is an unreachable asymptote, like the
speed of light for matter, but I'm (recently!) convinced that it's a
goal worthy of exploration and effort.
Seems to me that once you get beyond
Simon Forman sajmik...@gmail.com writes:
But I'm glad it's there to study, these are wheels I don't have to
invent for myself.
http://dwheeler.com/essays/high-assurance-floss.html
might be an interesting place to start.
--
http://mail.python.org/mailman/listinfo/python-list
On Jul 9, 1:20 pm, Steven D'Aprano st...@remove-this-
cybersource.com.au wrote:
[...]
You'll excuse my skepticism about all these claims about how anyone can
program, how easy it is to teach the fundamentals of Turing Machines and
functional programming to anybody at all. Prove it. Where are
In message pan.2009.07.14.03.45...@remove.this.cybersource.com.au, Steven
D'Aprano wrote:
Are we supposed to interpret that post as Dumb Insolence or just Dumb?
Insolence indeed ... another wanker to plonk, I think.
--
http://mail.python.org/mailman/listinfo/python-list
In message h3bogf$oo...@panix3.panix.com, Aahz wrote:
In article h3bagu$52...@lust.ihug.co.nz,
Lawrence D'Oliveiro l...@geek-central.gen.new_zealand wrote:
In message h37gv5$r8...@panix3.panix.com, Aahz wrote:
It helps to remember that names and namespaces are in many
ways syntactic sugar
On Fri, 10 Jul 2009, Hendrik van Rooyen wrote:
Steven D'Aprano st...@remove-this-cye.com.au wrote:
On Wed, 08 Jul 2009 22:05:57 -0700, Simon Forman wrote:
[...]
Programming is not like any other human activity.
In practice? In principle? Programming in principle is not the same as it
I V ivle...@gmail.com (IV) wrote:
IV On Fri, 10 Jul 2009 16:27:12 -0400, Terry Reedy wrote:
a bug, bug a limitation due to using limited-range numbers. If one uses
residue classes instead of integers, and makes no adjustment, I consider
it wrong to blame Bentley.
IV But it was Bentley
Steven D'Aprano st...@remove-this-cyb.ce.com.au wrote:
On Fri, 10 Jul 2009 12:54:21 +0200, Hendrik van Rooyen wrote:
Steven D'Aprano st...@remove-this-cye.com.au wrote:
On Wed, 08 Jul 2009 22:05:57 -0700, Simon Forman wrote:
persistent idea out there that programming is a very
pdpi pd...@gmail.com wrote;
I've always found cooking an apt metaphor for programming.
No this is wrong.
Writing a recipe or a cookbook is like programming.
Cooking, following a recipe, is like running a program.
- Hendrik
--
http://mail.python.org/mailman/listinfo/python-list
Steven D'Aprano wrote:
Even *soup stock* fits the same profile as what Hendrik claims is almost
unique to programming. On its own, soup stock is totally useless. But you
make it, now, so you can you feed it into something else later on.
Or instant coffee.
I think I'll avoid coming to your
On Sat, 11 Jul 2009 14:01:25 +0200
Hendrik van Rooyen m...@microcorp.co.za wrote:
Programming is the step of going from the design to something
that tells the machine how to implement the design.
The creativity could, arguably, be in the Design.
Not in the translation to python, or
D'Arcy J.M. Cain d...@druid.net
One might also argue that divorcing the design from the code is the
problem in a lot of legacy code. See Agile Programming methods. Now
you could say that there is a design step still in talking to the
client and making a plan in your head or in some notes
John O'Hagan wrote:
The drawings produced by an architect, the script of a play, the score of a
piece of music, and the draft of a piece of legislation are all examples of
other things which are useless until they are interpreted in some way.
Granted.
But...
There are countless human
In message h37gv5$r8...@panix3.panix.com, Aahz wrote:
It helps to remember that names and namespaces are in many
ways syntactic sugar for dicts or lists.
Interesting, though, that Python insists on maintaining a distinction
between c[x] and c.x, whereas JavaScript doesn't bother.
--
Hendrik van Rooyen wrote:
The creativity could, arguably, be in the Design.
Not in the translation to python, or assembler.
No way. That is just coding.
No, the mechanical part of the process is called compiling,
and we have programs to do it for us.
By the time you've specified the design
Lawrence D'Oliveiro wrote:
Interesting, though, that Python insists on maintaining a distinction
between c[x] and c.x, whereas JavaScript doesn't bother.
And that distinction is a good thing. It means, for
example, that dictionaries can have methods without
colliding with the key space of the
In article h3bagu$52...@lust.ihug.co.nz,
Lawrence D'Oliveiro l...@geek-central.gen.new_zealand wrote:
In message h37gv5$r8...@panix3.panix.com, Aahz wrote:
It helps to remember that names and namespaces are in many
ways syntactic sugar for dicts or lists.
Interesting, though, that Python
Steven D'Aprano st...@remove-this-cye.com.au wrote:
On Wed, 08 Jul 2009 22:05:57 -0700, Simon Forman wrote:
persistent idea out there that programming is a very accessible
skill, like cooking or gardening, anyone can do it, and even profit
from it, monetarily or otherwise, etc., and to
On Fri, 10 Jul 2009 12:54:21 +0200, Hendrik van Rooyen wrote:
Steven D'Aprano st...@remove-this-cye.com.au wrote:
On Wed, 08 Jul 2009 22:05:57 -0700, Simon Forman wrote:
persistent idea out there that programming is a very accessible
skill, like cooking or gardening, anyone can do it,
[excessive quoting ahead, I'm too tired to trim]
In article h32i2o$eo...@reader1.panix.com, kj no.em...@please.post wrote:
In h32fon$26...@panix3.panix.com a...@pythoncraft.com (Aahz) writes:
In article h32eoh$ql...@reader1.panix.com, kj no.em...@please.post wrote:
OK, so, scratching from my
On Fri, 10 Jul 2009 08:28:29 -0700, Scott David Daniels wrote:
Steven D'Aprano wrote:
Even *soup stock* fits the same profile as what Hendrik claims is
almost unique to programming. On its own, soup stock is totally
useless. But you make it, now, so you can you feed it into something
else
On 10 Jul 2009 15:48:47 GMT
Steven D'Aprano st...@remove-this-cybersource.com.au wrote:
I meant the instant coffee powder is prepared in advance. It's useless on
it's own, but later on you feed it into boiling water, add sugar and
milk, and it's slightly less useless.
I don't know about
On Jul 10, 2:11 pm, Steven D'Aprano st...@remove-this-
cybersource.com.au wrote:
On Fri, 10 Jul 2009 12:54:21 +0200, Hendrik van Rooyen wrote:
Steven D'Aprano st...@remove-this-cye.com.au wrote:
On Wed, 08 Jul 2009 22:05:57 -0700, Simon Forman wrote:
persistent idea out there that
On Jul 7, 1:04 pm, kj no.em...@please.post wrote:
I'm having a hard time coming up with a reasonable way to explain
certain things to programming novices.
:
How do I explain to rank beginners (no programming experience at
all) why x and y remain unchanged above, but not z?
:
What do
Steven D'Aprano wrote:
On Fri, 10 Jul 2009 08:28:29 -0700, Scott David Daniels wrote:
Steven D'Aprano wrote:
Even *soup stock* fits the same profile as what Hendrik claims is
almost unique to programming. On its own, soup stock is totally
useless. But you make it, now, so you can you feed it
Steven D'Aprano wrote:
On Thu, 09 Jul 2009 23:07:34 -0400, Terry Reedy wrote:
The is *not* a bug is Bentley program.
This is *not* a bug in Bentley's program.
Wow. That's an impressive set of typos :)
3. Way beneath my usual standards ;-)
It is a bug in bad, buggy, insane
integer
On Fri, 10 Jul 2009 16:27:12 -0400, Terry Reedy wrote:
a bug, bug a limitation due to using limited-range numbers. If one uses
residue classes instead of integers, and makes no adjustment, I consider
it wrong to blame Bentley.
But it was Bentley himself who used the C int type, so it hardly
I V wrote:
On Fri, 10 Jul 2009 16:27:12 -0400, Terry Reedy wrote:
a bug, bug a limitation due to using limited-range numbers. If one uses
residue classes instead of integers, and makes no adjustment, I consider
it wrong to blame Bentley.
But it was Bentley himself who used the C int type, so
Bearophile wrote:
kj, as Piet van Oostrum as said, that's the difference between mutable
an immutable. It comes from the procedural nature of Python, and
probably an explanation of such topic can't be avoided if you want to
learn/teach Python.
The problem with Python's mutable/immutable
Dave Angel wrote:
By the time I graduated, I had five six-level languages
^^^
Are they languages that you have to edit using vi? :-)
--
Greg
--
http://mail.python.org/mailman/listinfo/python-list
greg wrote:
div class=moz-text-flowed style=font-family: -moz-fixedDave
Angel wrote:
By the time I graduated, I had five six-level languages
^^^
Are they languages that you have to edit using vi? :-)
Back then I didn't need glasses. That was of course
On Thu, Jul 9, 2009 at 1:05 AM, Simon Formansajmik...@gmail.com wrote:
Everyone gets so caught up in programming via languages that
you get, well, people trying to teach Computer Programming as if it
were only necessary to grok a language, rather than grokking /symbol
manipulation/ itself.
On Wed, 08 Jul 2009 22:05:57 -0700, Simon Forman wrote:
The core abstractions of [mechanical] computation are just not that
complicated. You can teach them to anybody in about a half an hour,
drunk. I have.
That's *easy*. Anyone can teach the most complicated and abstract
principles of any
On Wed, 08 Jul 2009 22:05:57 -0700, Simon Forman wrote:
persistent idea out there that programming is a very accessible
skill, like cooking or gardening, anyone can do it, and even profit
from it, monetarily or otherwise, etc., and to some extent I am
Programming is not like any other human
On Thu, 2009-07-09 at 18:10 +, Steven D'Aprano wrote:
If programming is symbol manipulation, then you should remember that
the
user interface is also symbol manipulation, and it is a MUCH harder
problem than databases, sorting, searching, and all the other
problems
you learn about in
Steven D'Aprano wrote:
There is some evidence that 30-60% of people simply cannot learn to
program, no matter how you teach them:
http://www.codinghorror.com/blog/archives/000635.html
http://www.cs.mdx.ac.uk/research/PhDArea/saeed/
I'm sympathetic to the idea, but not entirely convinced.
In message h3291j$mf...@reader1.panix.com, kj wrote:
.., Lundh writes:
Assignment statements modify namespaces, not objects.
counterexample
a = [3]
b = a
These may indeed modify a namespace, not any object. However:
a[:] = [4]
a
[4]
b
[4]
What change
Steven D'Aprano wrote:
And speaking of binary search:
[quote]
I was shocked to learn that the binary search program that Bentley PROVED
CORRECT and SUBSEQUENTLY TESTED [emphasis added] in Chapter 5 of
Programming Pearls contains a bug. Once I tell you what the it is, you
will understand why
On Thu, 09 Jul 2009 23:07:34 -0400, Terry Reedy wrote:
Steven D'Aprano wrote:
And speaking of binary search:
[quote]
I was shocked to learn that the binary search program that Bentley
PROVED CORRECT and SUBSEQUENTLY TESTED [emphasis added] in Chapter 5 of
Programming Pearls contains a
On Tue, 07 Jul 2009 20:04:46 +, kj wrote:
I'm having a hard time coming up with a reasonable way to explain
certain things to programming novices.
[...]
Or consider this one:
ham = [1, 2, 3, 4]
spam = (ham,)
spam
([1, 2, 3, 4],)
spam[0] is ham
True
spam[0] += [5]
Traceback
On Jul 7, 10:04 pm, kj no.em...@please.post wrote:
I'm having a hard time coming up with a reasonable way to explain
certain things to programming novices.
Consider the following interaction sequence:
def eggs(some_int, some_list, some_tuple):
... some_int += 2
... some_list +=
En Wed, 08 Jul 2009 04:32:07 -0300, Francesco Bochicchio
bieff...@gmail.com escribió:
I would go with something like this:
In object oriented programming, the same function or operator can be
used to represent
different things. This is called overloading. To understand what the
Simon Forman sajmik...@gmail.com (SF) wrote:
SF Why would you even tell the poor bastards about += before they were
SF comfortable with (python's style of) function calls, immutable
SF integers, mutable lists and immutable tuples?
SF Let them use x = x + y until they have enough knowledge to
SF
Bearophile wrote:
For example a novice wants to see 124 / 38 to return the 62/19
fraction and not 3 or 3.263157894736842 :-)
Python has adopted the latter of the three for operator / and the the second
one for operator //. I wonder if it was considered to just return a
fraction from that
In c75ei6-e0i@satorlaser.homedns.org Ulrich Eckhardt
eckha...@satorlaser.com writes:
Bearophile wrote:
For example a novice wants to see 124 / 38 to return the 62/19
fraction and not 3 or 3.263157894736842 :-)
Python has adopted the latter of the three for operator / and the the second
In 5f0a2722-45eb-468c-b6b2-b7bb80ae5...@q11g2000yqi.googlegroups.com Simon
Forman sajmik...@gmail.com writes:
Frankly, I'm of the impression that it's a mistake not to start
teaching programming with /the bit/ and work your way up from there.
I'm not kidding. I wrote a (draft) article about
On Wed, 08 Jul 2009 11:24:28 +0200, Ulrich Eckhardt wrote:
Bearophile wrote:
For example a novice wants to see 124 / 38 to return the 62/19 fraction
and not 3 or 3.263157894736842 :-)
Python has adopted the latter of the three for operator / and the the
second one for operator //.
Up
On Wed, 08 Jul 2009 12:23:50 +, kj wrote:
In 5f0a2722-45eb-468c-b6b2-b7bb80ae5...@q11g2000yqi.googlegroups.com
Simon Forman sajmik...@gmail.com writes:
Frankly, I'm of the impression that it's a mistake not to start teaching
programming with /the bit/ and work your way up from there. I'm
In 5f0a2722-45eb-468c-b6b2-b7bb80ae5...@q11g2000yqi.googlegroups.com Simon
Forman sajmik...@gmail.com writes:
I'm not kidding. I wrote a (draft) article about this: Computer
Curriculum http://docs.google.com/View?id=dgwr777r_31g4572gp4
Very cool.
kj
--
2009/7/8 kj no.em...@please.post:
There is this
persistent idea out there that programming is a very accessible
skill, like cooking or gardening, anyone can do it, and even profit
from it, monetarily or otherwise, etc., and to some extent I am
actively contributing to this perception by
On Jul 7, 5:18 pm, kj no.em...@please.post wrote:
In mailman.2796.1246997332.8015.python-l...@python.org Chris Rebert
c...@rebertia.com writes:
You might find the following helpful (partially):
http://effbot.org/zone/call-by-object.htm
Extremely helpful. Thanks! (I learned more from it
In h30e3t$g5...@reader1.panix.com kj no.em...@please.post writes:
I had not realized how *profoundly* different the meaning of the
= in Python's
spam = ham
is from the = in its
spam[3] = ham[3]
To clarify, this comes from my reading of Fredrik Lundh's pages
Python Objects
On 8 Jul, 16:04, kj no.em...@please.post wrote:
identifier = expression
and not to those like, for example,
identifier[expression] = expression
or
identifier.identifier = expression
The former are syntatic sugar for certain namespace modifications
that leave objects unchanged.
In 0778f257-d36c-4e13-93ea-bf8d448c8...@b15g2000yqd.googlegroups.com Paul
Boddie p...@boddie.org.uk writes:
On 8 Jul, 16:04, kj no.em...@please.post wrote:
=A0 identifier =3D expression
and not to those like, for example,
=A0 identifier[expression] =3D expression
or
=A0
In article 0778f257-d36c-4e13-93ea-bf8d448c8...@b15g2000yqd.googlegroups.com,
Paul Boddie p...@boddie.org.uk wrote:
Almost. The latter can modify namespaces - the objects themselves -
but through properties or dynamic attribute access, they may choose
not to modify such a namespace. Really, we
kj wrote:
In 5f0a2722-45eb-468c-b6b2-b7bb80ae5...@q11g2000yqi.googlegroups.com Simon Forman
sajmik...@gmail.com writes:
Frankly, I'm of the impression that it's a mistake not to start
teaching programming with /the bit/ and work your way up from there.
I'm not kidding. I wrote a (draft)
In article h32eoh$ql...@reader1.panix.com, kj no.em...@please.post wrote:
OK, so, scratching from my original post the case
identifier.identifier = expression
(as being a special case of identifier = expression), still,
to the extent that I understand your post, the = in
x = 1
means
In h32fon$26...@panix3.panix.com a...@pythoncraft.com (Aahz) writes:
In article h32eoh$ql...@reader1.panix.com, kj no.em...@please.post wrote:
OK, so, scratching from my original post the case
identifier.identifier = expression
(as being a special case of identifier = expression), still,
to
kj wrote:
To clarify, this comes from my reading of Fredrik Lundh's pages
Python Objects (http://effbot.org/zone/python-objects.htm) and
Call By Object (http://effbot.org/zone/call-by-object.htm).
[snip]
[END OF LENGTHY QUOTE]
Therefore, extending just a bit beyond Lundh's explanation, if we
(I wanted to reply to a few messages in one post so I quoted them all
below. Let me know if this is bad etiquette.)
On Jul 8, 8:23 am, kj no.em...@please.post wrote:
In 5f0a2722-45eb-468c-b6b2-b7bb80ae5...@q11g2000yqi.googlegroups.com Simon
Forman sajmik...@gmail.com writes:
Frankly, I'm of
I'm having a hard time coming up with a reasonable way to explain
certain things to programming novices.
Consider the following interaction sequence:
def eggs(some_int, some_list, some_tuple):
... some_int += 2
... some_list += [2]
... some_tuple += (2,)
...
x = 42
y = (42,)
z
On Tue, Jul 7, 2009 at 1:04 PM, kjno.em...@please.post wrote:
I'm having a hard time coming up with a reasonable way to explain
certain things to programming novices.
Consider the following interaction sequence:
def eggs(some_int, some_list, some_tuple):
... some_int += 2
...
kj no.em...@please.post (k) wrote:
k I'm having a hard time coming up with a reasonable way to explain
k certain things to programming novices.
k Consider the following interaction sequence:
def eggs(some_int, some_list, some_tuple):
k ... some_int += 2
k ... some_list += [2]
k ...
In m2my7gb4g6@cs.uu.nl Piet van Oostrum p...@cs.uu.nl writes:
kj no.em...@please.post (k) wrote:
k I'm having a hard time coming up with a reasonable way to explain
k certain things to programming novices.
k Consider the following interaction sequence:
def eggs(some_int, some_list,
In mailman.2796.1246997332.8015.python-l...@python.org Chris Rebert
c...@rebertia.com writes:
You might find the following helpful (partially):
http://effbot.org/zone/call-by-object.htm
Extremely helpful. Thanks! (I learned more from it than someone
who will teach the stuff would care to
kj, as Piet van Oostrum as said, that's the difference between mutable
an immutable. It comes from the procedural nature of Python, and
probably an explanation of such topic can't be avoided if you want to
learn/teach Python.
Lot of people think that a language where everything is immutable is
Bearophile wrote:
kj, as Piet van Oostrum as said, that's the difference between mutable
an immutable. It comes from the procedural nature of Python, and
probably an explanation of such topic can't be avoided if you want to
learn/teach Python.
...(snip)
See you later,
bearophile
I really enjoyed your boxes analogy, from a guy with a trucking background,
it makes a lot of sense!
-Bret
... The more I delve into OOP the more I liken an 'object' to a box. A box
with a shipping manifest.
There are big boxes,
little boxes,
squat boxes and so on.
A box can contain corn
kj no.em...@please.post writes:
In mailman.2796.1246997332.8015.python-l...@python.org Chris Rebert
c...@rebertia.com writes:
You might find the following helpful (partially):
http://effbot.org/zone/call-by-object.htm
Extremely helpful. Thanks! (I learned more from it than someone
On Jul 7, 5:11 pm, kj no.em...@please.post wrote:
I don't plan to present these examples to them.
But beginners have a way of bumping into such
conundrums all on their own [...]. I doubt that
an answer of the form don't worry your pretty
little head over this now; wait until your second
On Jul 7, 8:06 pm, Ben Finney ben+pyt...@benfinney.id.au wrote:
I have got very good results from teaching using
the analogy of “paper tags tied to physical objects”
to describe Python's references to values.
Ah, I like that! I think it's better than what I used in my post
(which I composed
On Tue, 07 Jul 2009 21:18:53 +, kj wrote:
I had not realized how *profoundly* different the meaning of the = in
Python's
spam = ham
is from the = in its
spam[3] = ham[3]
So much for explicit is better than implicit...
I'm sorry, I don't get it. Can you explain please? I
Ben,
I have got very good results from teaching using the analogy of paper tags
tied to physical objects to describe Python's references to values.
Great analogy!! And an excellent analogy for newcomers to Python. (this
would have saved me some personal pain in my early days).
Regards,
En Tue, 07 Jul 2009 17:04:46 -0300, kj no.em...@please.post escribió:
I'm having a hard time coming up with a reasonable way to explain
certain things to programming novices.
ham = [1, 2, 3, 4]
spam = (ham,)
spam
([1, 2, 3, 4],)
spam[0] is ham
True
spam[0] += [5]
Traceback (most recent
On Jul 7, 4:04 pm, kj no.em...@please.post wrote:
I'm having a hard time coming up with a reasonable way to explain
certain things to programming novices.
Consider the following interaction sequence:
def eggs(some_int, some_list, some_tuple):
... some_int += 2
... some_list +=
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