On 2008-11-20, greg [EMAIL PROTECTED] wrote:
Antoon Pardon wrote:
You are changing your argument. In a follow up you
made the point that call by value should be as it
was intended by the writers of the algol 60 report.
No, I was countering the argument that call by value
is short for call
Aaron Brady [EMAIL PROTECTED] writes:
Truth and clarity are not tired of this thread.
This is such a marvellously economic way of putting it, it's poetic!
--
Arnaud
--
http://mail.python.org/mailman/listinfo/python-list
On Tue, Nov 18, 2008 at 09:23:30AM +, Steven D'Aprano wrote:
How I can answer the question, are the objects a and b the same or
different? I can look at every aspect of each object, looking for
something that is different.
Well, sure, if you care *that much* about potentially trivial
Derek Martin wrote:
[some stuff, followed by about 32k of unnecessarily quoted crap]
It would be helpful if you'd take the time to trim your replies
appropriately.
regards
Steve
--
Steve Holden+1 571 484 6266 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/
--
On Sun, 23 Nov 2008 09:24:05 -0600, Derek Martin wrote:
On Tue, Nov 18, 2008 at 09:23:30AM +, Steven D'Aprano wrote:
How I can answer the question, are the objects a and b the same or
different? I can look at every aspect of each object, looking for
something that is different.
On Nov 21, 8:53 pm, greg [EMAIL PROTECTED] wrote:
Aaron Brady wrote:
Call-by-value has other characteristics that Python does not
meet.
The designers of most other dynamic languages don't
seem to share that opinion, since they use the term
call-by-value just as though it *does* mean call-
On Nov 22, 2008, at 4:08 AM, Aaron Brady wrote:
Furthermore, to apply c-b-v to Python, you have to
introduce the concept of pointers, which is ostensibly non-native for
human programmers.
Not necessarily pointers per se -- any type of object references
will do, and yes, Python has those in
On Nov 22, 8:40 am, Joe Strout [EMAIL PROTECTED] wrote:
On Nov 22, 2008, at 4:08 AM, Aaron Brady wrote:
Furthermore, to apply c-b-v to Python, you have to
introduce the concept of pointers, which is ostensibly non-native for
human programmers.
Not necessarily pointers per se -- any type
Steven D'Aprano [EMAIL PROTECTED] wrote:
On Fri, 21 Nov 2008 03:32:25 +, Steven D'Aprano wrote:
Rather it seems to me that the essence of the idea they had in mind
is that call-by-value is equivalent to assignment.
You've just *assumed* that assignment in Algol 60 doesn't involving
On Nov 21, 3:11 am, Duncan Booth [EMAIL PROTECTED] wrote:
Steven D'Aprano [EMAIL PROTECTED] wrote:
On Fri, 21 Nov 2008 03:32:25 +, Steven D'Aprano wrote:
Rather it seems to me that the essence of the idea they had in mind
is that call-by-value is equivalent to assignment.
You've
Aaron Brady [EMAIL PROTECTED] wrote:
a[:] = [1, 2, 3]
No, that's not assignment, it's syntactic sugar for a __setslice__
call. No copies here.
Oh dear, perhaps you had better get the Python developers to update the
grammar that Python uses as that seems to think it's an assignment:
On Nov 21, 4:33 am, Duncan Booth [EMAIL PROTECTED] wrote:
Aaron Brady [EMAIL PROTECTED] wrote:
a[:] = [1, 2, 3]
No, that's not assignment, it's syntactic sugar for a __setslice__
call. No copies here.
Oh dear, perhaps you had better get the Python developers to update the
grammar that
Aaron Brady wrote:
But wait, is that true assignment?
It's assignment, but it's not really copying an object. No new
objects are being created -- rather, some of the items within
the lhs object are being rebound to already-existing objects.
It would be possible for the lhs object's
Aaron Brady wrote:
Tell me, what happens during a call to the following C++ function?
void f( std::vector int x );
The same thing as would happen if you wrote
std::vectorint x = actual_parameter_expression;
what happens during a call to the following Python
function?
def f( x ): ...
Steven D'Aprano wrote:
You've just *assumed* that assignment in Algol 60 doesn't involving
copying.
I've done no such thing. I've *refrained* from assuming that
the assignment in the definition always has to refer to
Algol 60 assignment. You're the one insisting on tying
everything to Algol.
On Nov 21, 7:06 pm, greg [EMAIL PROTECTED] wrote:
Aaron Brady wrote:
Tell me, what happens during a call to the following C++ function?
void f( std::vector int x );
The same thing as would happen if you wrote
std::vectorint x = actual_parameter_expression;
what happens during a
Aaron Brady wrote:
Call-by-value has other characteristics that Python does not
meet.
The designers of most other dynamic languages don't
seem to share that opinion, since they use the term
call-by-value just as though it *does* mean call-
by-assignment and nothing more.
--
Greg
--
On Nov 19, 7:22 pm, greg [EMAIL PROTECTED] wrote:
Antoon Pardon wrote:
You are changing your argument. In a follow up you
made the point that call by value should be as it
was intended by the writers of the algol 60 report.
No, I was countering the argument that call by value
is short
On Thu, 20 Nov 2008 14:22:50 +1300, greg wrote:
Antoon Pardon wrote:
You are changing your argument. In a follow up you made the point that
call by value should be as it was intended by the writers of the algol
60 report.
No, I was countering the argument that call by value is short for
On Wed, 19 Nov 2008 11:20:05 -0500, Terry Reedy wrote:
It is useful and convenient to have null values like None, but it
isn't useful to say that None is not a value.
I never said that.
But you've been defending the views of somebody who did. If you're going
to play Devil's Advocate for
Steven D'Aprano wrote:
On Thu, 20 Nov 2008 14:22:50 +1300, greg wrote:
Antoon Pardon wrote:
You are changing your argument. In a follow up you made the point that
call by value should be as it was intended by the writers of the algol
60 report.
No, I was countering the argument that call by
On Fri, 21 Nov 2008 03:32:25 +, Steven D'Aprano wrote:
Rather it seems to me that the essence of the idea they had in mind is
that call-by-value is equivalent to assignment.
You've just *assumed* that assignment in Algol 60 doesn't involving
copying. Based on the very little I know
On 2008-11-19, greg [EMAIL PROTECTED] wrote:
Antoon Pardon wrote:
Call by value is officially defined in terms of assignment in
a context where assignments means copying and in a definition
of a specifix language.
You can't lift this part out of the definition of algol 60
and say it
Steven D'Aprano wrote:
On Tue, 18 Nov 2008 15:55:10 -0500, Terry Reedy wrote:
To me, that distortion of his (and my) point is silly. 0 partipipates
in numerous integer operations, whereas None participates in no NoneType
operations. (Neither has attributes.) And that is the difference he
[EMAIL PROTECTED] wrote:
On Nov 18, 10:22 am, Steve Holden [EMAIL PROTECTED] wrote
in thread Python-URL! weekly Python news and links (Nov 17):
[EMAIL PROTECTED] wrote:
[...]
One of the reasons I would like to formulate a good
model of an object's value and type is so that I could
try to
Antoon Pardon wrote:
You are changing your argument. In a follow up you
made the point that call by value should be as it
was intended by the writers of the algol 60 report.
No, I was countering the argument that call by value
is short for call by copying the value. I was pointing
out that
On 2008-11-12, greg [EMAIL PROTECTED] wrote:
Here is the definition of call-by-value from the
Revised Report on the Algorithmic Language Algol 60
http://www.masswerk.at/algol60/report.htm:
4.7.3.1. Value assignment (call by value). All formal parameters quoted in
the
value part of the
On Nov 18, 2:21 am, Antoon Pardon [EMAIL PROTECTED] wrote:
On 2008-11-12, greg [EMAIL PROTECTED] wrote:
Here is the definition of call-by-value from the
Revised Report on the Algorithmic Language Algol 60
http://www.masswerk.at/algol60/report.htm:
4.7.3.1. Value assignment (call by
On Sun, 16 Nov 2008 15:46:54 -0800, rurpy wrote:
Since many responses to my definition of value raised similar points, I
will try and respond generally here.
In hindsight, I should not have used the word value; it is far too
overloaded with preexisting semantics for me to have attempted to
On 2008-11-12, greg [EMAIL PROTECTED] wrote:
Steven D'Aprano wrote:
Why should anyone take the Revised Report on the Algorithmic Language
Algol 60 as the official (only?) definition of call-by-value for all
languages everywhere?
Since the term was more or less invented by the people
who
Steven D'Aprano wrote:
On Mon, 17 Nov 2008 18:35:04 -0800, Craig Allen wrote:
* Do all objects have values? (Ignore the Python
docs if necessary.)
If one allows null values, I am current thinking yes.
I don't see a difference between a null value and not having a value.
I think the
On Nov 17, 7:35 pm, Craig Allen [EMAIL PROTECTED] wrote:
* Do all objects have values? (Ignore the Python
docs if necessary.)
If one allows null values, I am current thinking yes.
I don't see a difference between a null value
and not having a value.
I think the difference is
Steven D'Aprano wrote:
On Sun, 16 Nov 2008 15:46:54 -0800, rurpy wrote:
For example, consider the two electrons around a helium nucleus. They
have the same mass, the same speed, the same spin, the same electric
charge, the same magnetic moment, they even have the same location in
space
On Nov 18, 2:55 pm, Terry Reedy [EMAIL PROTECTED] wrote:
Steven D'Aprano wrote:
On Sun, 16 Nov 2008 15:46:54 -0800, rurpy wrote:
For example, consider the two electrons around a helium nucleus. They
have the same mass, the same speed, the same spin, the same electric
charge, the same
Terry Reedy wrote:
Steven D'Aprano wrote:
On Sun, 16 Nov 2008 15:46:54 -0800, rurpy wrote:
For example, consider the two electrons around a helium nucleus. They
have the same mass, the same speed, the same spin, the same electric
charge, the same magnetic moment, they even have the same
Antoon Pardon wrote:
Call by value is officially defined in terms of assignment in
a context where assignments means copying and in a definition
of a specifix language.
You can't lift this part out of the definition of algol 60
and say it applies equally well in languages with different
On Nov 18, 10:22 am, Steve Holden [EMAIL PROTECTED] wrote
in thread Python-URL! weekly Python news and links (Nov 17):
[EMAIL PROTECTED] wrote:
[...]
One of the reasons I would like to formulate a good
model of an object's value and type is so that I could
try to offer something better.
On Tue, 18 Nov 2008 15:55:10 -0500, Terry Reedy wrote:
Steven D'Aprano wrote:
On Sun, 16 Nov 2008 15:46:54 -0800, rurpy wrote:
For example, consider the two electrons around a helium nucleus. They
have the same mass, the same speed, the same spin, the same electric
charge, the same
En Wed, 19 Nov 2008 01:14:28 -0200, [EMAIL PROTECTED] escribió:
On Nov 18, 10:22 am, Steve Holden [EMAIL PROTECTED] wrote
in thread Python-URL! weekly Python news and links (Nov 17):
[EMAIL PROTECTED] wrote:
[...]
One of the reasons I would like to formulate a good
model of an object's value
* Do all objects have values? (Ignore the Python
docs if necessary.)
If one allows null values, I am current thinking yes.
I don't see a difference between a null value
and not having a value.
I think the difference is concrete... an uninitialized variable in C
has no value, I'd say,
On Nov 17, 8:35 pm, Craig Allen [EMAIL PROTECTED] wrote:
* Do all objects have values? (Ignore the Python
docs if necessary.)
If one allows null values, I am current thinking yes.
I don't see a difference between a null value
and not having a value.
I think the difference is
On Sun, 16 Nov 2008 23:34:58 -0500, Terry Reedy wrote:
Steven D'Aprano wrote:
class EqualsAll(object):
... def __eq__(self, other):
... return True
...
5 == EqualsAll()
True
The methods of 5 don't even get called.
Why do you say that? As I read the manual,
On Mon, 17 Nov 2008 18:35:04 -0800, Craig Allen wrote:
* Do all objects have values? (Ignore the Python
docs if necessary.)
If one allows null values, I am current thinking yes.
I don't see a difference between a null value and not having a value.
I think the difference is
On Thu, Nov 13, 2008 at 11:58:18AM -0800, [EMAIL PROTECTED] wrote:
I have yet to see any reasonable definition of a Python value in the
Python docs or elsewhere, despite the fact that a value is one of
the three defining characteristics of an object, a central concept
in Python.
Why does it
On Sat, 15 Nov 2008 19:41:20 -0800, rurpy wrote:
I prefer another definition of object: an object *is* a value, rather
than *has* a value. That value consists of identity, type (or class),
and everything else of interest which is sometimes also called value.
Since identity is usually
On Sun, Nov 16, 2008 at 06:06:20AM +, Steven D'Aprano wrote:
* Do all objects have values? (Ignore the Python
docs if necessary.)
If one allows null values, I am current thinking yes.
I don't see a difference between a null value and not having a value.
[...]
It wasn't until
On Sun, Nov 16, 2008 at 08:38:25AM +, Steven D'Aprano wrote:
I believe that the language reference says that objects have an identity,
a type and state, but I'm too lazy too look it up. I'd be happy with that
definition.
They do indeed say value, not state. As I said in a different
Derek Martin [EMAIL PROTECTED] writes:
On Thu, Nov 13, 2008 at 11:58:18AM -0800, [EMAIL PROTECTED] wrote:
I have yet to see any reasonable definition of a Python value in the
Python docs or elsewhere, despite the fact that a value is one of
the three defining characteristics of an object, a
On Sun, Nov 16, 2008 at 09:30:45AM +, Arnaud Delobelle wrote:
[...]
If you like, you could think of the value of an object as the set of
all possible values to which the object may evaluate in every possible
context, given a particular state of the object.
This definition looks a bit
Derek Martin [EMAIL PROTECTED] writes:
I think he meant None... Or at least, I personally see a distinction
between zero and None (and so do the Python docs). Zero is a value,
whereas None is specifically intended to denote the lack of any value.
None is an 'value' which is intended to
On Sat, 15 Nov 2008 19:42:33 -0800, rurpy wrote:
You are saying there is no objective definition of value. I disagree.
I think one can define value in a useful way that is precise,
objective, and useful.
No, I'm not saying that there is no objective definition of value. I'm
saying that the
On Sun, 16 Nov 2008 04:12:53 -0500, Derek Martin wrote:
On Sun, Nov 16, 2008 at 06:06:20AM +, Steven D'Aprano wrote:
* Do all objects have values? (Ignore the Python
docs if necessary.)
If one allows null values, I am current thinking yes.
I don't see a difference between a
Steven D'Aprano wrote:
On Sat, 15 Nov 2008 19:42:33 -0800, rurpy wrote:
[...]
But I propose that one can define value in a precise way that
captures what most people think of as value, and avoids confusing
objects (or references to them) and the value of objects.
Good luck. I think you're
Steven D'Aprano wrote:
On Sat, 15 Nov 2008 11:17:07 -0800, rurpy wrote:
[...]
* How can I find an object's value (if I don't believe
.str(), .repr(), etc)? Use gdb. :-)
I would say the object's value is the value, so if you have the object,
you have its value.
[...]
There's also the
Since many responses to my definition of
value raised similar points, I will try
and respond generally here.
In hindsight, I should not have used the
word value; it is far too overloaded with
preexisting semantics for me to have attempted
to redefine it, even if it is the word used
(but not
[EMAIL PROTECTED] wrote:
Since many responses to my definition of
value raised similar points, I will try
and respond generally here.
In hindsight, I should not have used the
word value; it is far too overloaded with
preexisting semantics for me to have attempted
to redefine it, even if
Steven D'Aprano wrote:
Because of
Python's interpreted nature, names can't be compiled away as in C, they
need a concrete runtime existence, but does the language definition need
to assume that?
Of course. It wouldn't be Python if they didn't. However, remember that
objects don't have names.
On Nov 16, 5:12 pm, Steve Holden [EMAIL PROTECTED] wrote:
The Python Reference Manual states that an object
consists of identity, type, and value. Identity
seems to be non-controversial.
Let's take type as meaning the attributes an
object inherits from it's class. value is then
what is
[EMAIL PROTECTED] wrote:
Or one could adopt what Terry Reedy called a
4-aspect view: an object is identity, class,
value (or local-state or something) and
intrinsic-value.
What I specifically said is id, class, instance attributes, and private
data. So objects have only one, some only the
On Nov 15, 12:51 am, Steven D'Aprano [EMAIL PROTECTED]
cybersource.com.au wrote:
On Fri, 14 Nov 2008 22:56:52 -0500, Terry Reedy wrote:
snip
I would say that the answer to this is, Would you like to include
behaviour in value?. Let me give you an example:
class String(string):
def
[EMAIL PROTECTED] writes:
I have yet to see any reasonable definition of a Python
value in the Python docs or elsewhere, despite the fact
that a value is one of the three defining characteristics
of an object, a central concept in Python.
I don't remember how the expression 'object value' is
On Nov 14, 8:56 pm, Terry Reedy [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
On Nov 13, 4:53 pm, Terry Reedy wrote:
[EMAIL PROTECTED] wrote:
I have yet to see any reasonable definition of a Python
value in the Python docs or elsewhere, despite the fact
that a value is one of the three
[EMAIL PROTECTED] wrote:
On Nov 14, 8:56 pm, Terry Reedy [EMAIL PROTECTED] wrote:
First of all, thanks. Thanks to your answers I have
finally been able to formulate a concept of Python
values. Now we'll see if it is valid/usable... :-)
Good questions help refine a concept.
* Can I create
On Nov 15, 4:12 pm, Terry Reedy [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
On Nov 14, 8:56 pm, Terry Reedy [EMAIL PROTECTED] wrote:
...snip...
* Does an object's behavior (methods) affect
its value?
My first answer is No. Instance methods are attributes of a class and,
in most
[Tried multiple times to post this but Google errors
out so will try posting in two parts... this is part 1]
On Nov 14, 11:51 pm, Steven D'Aprano [EMAIL PROTECTED]
cybersource.com.au wrote:
On Fri, 14 Nov 2008 22:56:52 -0500, Terry Reedy wrote:
[EMAIL PROTECTED] wrote:
On Nov 13, 4:53 pm,
[Tried multiple times to post this but Google errors
out so will try posting in two parts... this is part 2]
On Nov 14, 11:51 pm, Steven D'Aprano [EMAIL PROTECTED]
cybersource.com.au wrote:
On Fri, 14 Nov 2008 22:56:52 -0500, Terry Reedy wrote:
[EMAIL PROTECTED] wrote:
On Nov 13, 4:53 pm, Terry
On Sat, 15 Nov 2008 11:17:07 -0800, rurpy wrote:
* Can I create an object that has a value that
is the same as int(3) without somehow using an int(3) object in its
construction?
[...]
Yes: mpz(3) where mpz is multi-precision int class with same set of
possible values as Python ints.
The
On Nov 13, 4:53 pm, Terry Reedy wrote:
[EMAIL PROTECTED] wrote:
I have yet to see any reasonable definition of a Python
value in the Python docs or elsewhere, despite the fact
that a value is one of the three defining characteristics
of an object, a central concept in Python.
I noticed
[EMAIL PROTECTED] wrote:
On Nov 13, 4:53 pm, Terry Reedy wrote:
[EMAIL PROTECTED] wrote:
I have yet to see any reasonable definition of a Python
value in the Python docs or elsewhere, despite the fact
that a value is one of the three defining characteristics
of an object, a central concept in
On Fri, 14 Nov 2008 22:56:52 -0500, Terry Reedy wrote:
[EMAIL PROTECTED] wrote:
On Nov 13, 4:53 pm, Terry Reedy wrote:
[EMAIL PROTECTED] wrote:
I have yet to see any reasonable definition of a Python value in the
Python docs or elsewhere, despite the fact that a value is one of the
three
Steve Holden wrote:
greg wrote:
Do you agree that it makes sense to talk about assigning
that value to something?
No. Why do you think that we are (mostly) careful to talk about binding
names and values instead?
That's an odd position to take, considering that the
Python docs use the word
Grant Edwards wrote:
I stopped paying much attention to this thread a while ago, but
you've got to admire the persistence of somebody who soldiers
on even though Aahz, Fredrik Lund, and Steve Holden are all on
the other side of the argument...
Those people clearly know a great deal about
On Nov 13, 3:44 am, greg [EMAIL PROTECTED] wrote:
Grant Edwards wrote:
I stopped paying much attention to this thread a while ago, but
you've got to admire the persistence of somebody who soldiers
on even though Aahz, Fredrik Lund, and Steve Holden are all on
the other side of the
Fredrik Lundh wrote:
Python's definition of the word value can be found in the language
reference:
http://docs.python.org/reference/datamodel.html#objects-values-and-types
That whole passage is talking almost
exclusively about the value of an *object*:
Every object has an identity, a
greg wrote:
If you're going to indulge in argument by authority,
you need to pick authorities that can be considered,
er, authoritative in the field concerned...
Like Barbara Liskov, who's won tons of awards for her work on computer
science and programming languages, and who was among the
On Nov 12, 2:05 pm, Fredrik Lundh [EMAIL PROTECTED] wrote:
Python's definition of the word value can be found in the language
reference:
http://docs.python.org/reference/datamodel.html#objects-values-and-types
Using that definition, a Python expression yields an object, not an
object value.
On 2008-11-13, greg [EMAIL PROTECTED] wrote:
Grant Edwards wrote:
I stopped paying much attention to this thread a while ago, but
you've got to admire the persistence of somebody who soldiers
on even though Aahz, Fredrik Lund, and Steve Holden are all on
the other side of the argument...
Fredrik Lundh wrote:
greg wrote:
If you're going to indulge in argument by authority,
you need to pick authorities that can be considered,
er, authoritative in the field concerned...
Like Barbara Liskov, who's won tons of awards for her work on computer
science and programming languages,
On Nov 12, 7:09 pm, George Sakkis [EMAIL PROTECTED] wrote:
On Nov 12, 4:05 pm, Fredrik Lundh [EMAIL PROTECTED] wrote:
greg wrote:
It's not only misleading, it's also a seriously flawed reading of the
original text - the Algol 60 report explicitly talks about assignment
of *values*.
Do
[EMAIL PROTECTED] wrote:
I have yet to see any reasonable definition of a Python
value in the Python docs or elsewhere, despite the fact
that a value is one of the three defining characteristics
of an object, a central concept in Python.
I noticed too. My try:
The value of an object is the
greg wrote:
Fredrik Lundh wrote:
It's not only misleading, it's also a seriously flawed reading of the
original text - the Algol 60 report explicitly talks about assignment
of *values*.
Do you agree that an expression in Python has a value?
Most expressions have values. The ones whose
On 2008-11-12, Steve Holden [EMAIL PROTECTED] wrote:
greg wrote:
I stopped paying much attention to this thread a while ago, but
you've got to admire the persistence of somebody who soldiers
on even though Aahz, Fredrik Lund, and Steve Holden are all on
the other side of the argument...
--
Fredrik Lundh wrote:
It's not only misleading, it's also a seriously flawed reading of the
original text - the Algol 60 report explicitly talks about assignment of
*values*.
Do you agree that an expression in Python has a value?
Do you agree that it makes sense to talk about assigning
that
Steven D'Aprano wrote:
Why should anyone take the Revised Report on the Algorithmic Language
Algol 60 as the official (only?) definition of call-by-value for all
languages everywhere?
Since the term was more or less invented by the people
who designed Algol, I thought it would be a good idea
Aahz wrote:
There you have it -- call by value is offially defined in
terms of assignment. There is no mention in there of copying.
So it's perfectly correct to use it in relation to Python.
Except, of course, for the fact that it is generally misleading.
It's not only misleading, it's
Steven D'Aprano wrote:
If you insist that Python is call by value, the only way that can work is
by defining values to be references, which is nothing like Algol.
No, that's not the only way. You can also make it work
by accepting the original definition of call-by-value
at face value -- i.e.
On Wed, Nov 12, 2008 at 2:01 PM, Steve Holden [EMAIL PROTECTED] wrote:
Now, can we get on to something substantive like how many angels can
dance on the head of a pin?
Oh, come on, that's too easy! 42.
I thought that by now everybody knew that.
Francesco
--
greg wrote:
It's not only misleading, it's also a seriously flawed reading of the
original text - the Algol 60 report explicitly talks about assignment
of *values*.
Do you agree that an expression in Python has a value?
Do you agree that it makes sense to talk about assigning
that value
In article [EMAIL PROTECTED],
Grant Edwards [EMAIL PROTECTED] wrote:
On 2008-11-12, Steve Holden [EMAIL PROTECTED] wrote:
greg wrote:
I stopped paying much attention to this thread a while ago, but
you've got to admire the persistence of somebody who soldiers
on even though Aahz, Fredrik Lund,
On Nov 12, 4:05 pm, Fredrik Lundh [EMAIL PROTECTED] wrote:
greg wrote:
It's not only misleading, it's also a seriously flawed reading of the
original text - the Algol 60 report explicitly talks about assignment
of *values*.
Do you agree that an expression in Python has a value?
Do
Here is the definition of call-by-value from the
Revised Report on the Algorithmic Language Algol 60
http://www.masswerk.at/algol60/report.htm:
4.7.3.1. Value assignment (call by value). All formal parameters quoted in the
value part of the procedure declaration heading are assigned the values
In article [EMAIL PROTECTED],
greg [EMAIL PROTECTED] wrote:
Here is the definition of call-by-value from the
Revised Report on the Algorithmic Language Algol 60
http://www.masswerk.at/algol60/report.htm:
4.7.3.1. Value assignment (call by value). All formal parameters quoted in the
value part
On Wed, 12 Nov 2008 13:10:10 +1300, greg wrote:
Here is the definition of call-by-value from the Revised Report on the
Algorithmic Language Algol 60
http://www.masswerk.at/algol60/report.htm:
Why should anyone take the Revised Report on the Algorithmic Language
Algol 60 as the official
On Wed, 12 Nov 2008 02:44:42 +, Steven D'Aprano wrote:
But one thing is clear: values aren't references. Given the assignment
x=1, the value of x is not a reference to 1 but 1 itself. So the one
thing we can unambiguously say is that Algol's assignment model is not
the same as Python's
Steven D'Aprano [EMAIL PROTECTED] writes:
I am very happy to say that x=1 implies that the value of x is the object
1 itself, in fact I would insist on such a definition of value.
If you insist that Python is call by value, the only way that can work is
by defining values to be references
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