Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-22 Thread Julien Salort
Le 20/05/2018 à 03:43, Steven D'Aprano a écrit : I've somewhat arbitrarily cut the list off at "languages ranked above 1% on TIOBE", but we have to cut the list of somewhere. And of course in certain specific industries the standard languages may be very different, e.g. there are still tens of m

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-22 Thread Carl Smith
I thought this thread did a good job of establishing that looking at other languages is not going to help with introducing assignment expressions into Python. It was still interesting to read. If we can't copy from other languages (or even agree on *which* languages to copy), Python will have to d

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Chris Angelico
On Tue, May 22, 2018 at 11:45 AM, Brendan Barnwell wrote: > On 2018-05-21 12:11, Chris Angelico wrote: >> >> Much more useful would be to look at languages that (a) work in a >> field where programmers have ample freedom to choose between >> languages, and (b) have been around long enough to actua

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Brendan Barnwell
On 2018-05-21 12:11, Chris Angelico wrote: Much more useful would be to look at languages that (a) work in a field where programmers have ample freedom to choose between languages, and (b) have been around long enough to actually demonstrate that people want to use them. Look through the Stack Ov

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Guido van Rossum
I don't know what to do with this thread. I enjoyed reading Mike's survey of what other languages do. I also enjoyed Chris's survey of what some other languages do. Then the thread veered off into several unproductive directions at once: a mini-tutorial for Rebol (or Red?), and endless bickering ab

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Franklin? Lee
On Mon, May 21, 2018 at 7:40 PM, Steven D'Aprano wrote: > On Mon, May 21, 2018 at 09:43:45AM -0700, Mike Miller wrote: >> To clarify there were three main criteria, and one minor. Newer, >> popular/becoming industry standard, and designed to address shortcomings in >> previous generations. Final

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Chris Angelico
On Tue, May 22, 2018 at 10:45 AM, Mike Miller wrote: > > On 2018-05-21 16:40, Steven D'Aprano wrote: > > Consider the link Chris sent above: > > https://insights.stackoverflow.com/survey/2018/#most-loved-dreaded-and-wanted > > The top six coincide with my list, plus TypeScript (superset of JS) and

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Mike Miller
On 2018-05-21 16:40, Steven D'Aprano wrote: Consider the link Chris sent above: https://insights.stackoverflow.com/survey/2018/#most-loved-dreaded-and-wanted The top six coincide with my list, plus TypeScript (superset of JS) and Python. I'm pretty happy with those chosen, considering. -Mik

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Mike Miller
On 2018-05-21 16:50, Steven D'Aprano wrote: Your conclusion does not follow even from the limited sample of They're not going in the direction of assignment-expressions everywhere, but rather one built in to the if/while statement. Coffeescript could certainly be a good candidate, though fa

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Steven D'Aprano
On Mon, May 21, 2018 at 10:00:01AM -0700, Mike Miller wrote: > It is true that := handles more (perhaps less-common) use cases, but > subjectively it is not as "Pythonic." Also doesn't appear to be the > direction the surveyed languages are going. Your conclusion does not follow even from the

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Steven D'Aprano
On Mon, May 21, 2018 at 09:43:45AM -0700, Mike Miller wrote: > To clarify there were three main criteria, and one minor. Newer, > popular/becoming industry standard, and designed to address shortcomings in > previous generations. Finally, the limit of my energy when already working > on a proj

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Carl Smith
If the ability to capture a subexpression is given up on, then we are are down to just capturing the value of the predicate in if statements. In loops, it is only the predicate and iteration index. If you mashup `if` and `def`, you end up with this mess: if get_something() def (value):

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Carl Smith
Chris makes a lot of good points regarding *which* languages to look at, but it seems like that line of enquiry is unlikely to suggest anything more than it has so far, especially if we're limiting it to languages everyone has heard of. They either use a keyword, an operator, don't support the feat

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Chris Angelico
On Tue, May 22, 2018 at 2:43 AM, Mike Miller wrote: > To clarify there were three main criteria, and one minor. Newer, > popular/becoming industry standard, and designed to address shortcomings in > previous generations. Finally, the limit of my energy when already working > on a project. Note

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Terry Reedy
On 5/21/2018 9:14 AM, Rhodri James wrote: On 21/05/18 12:29, Daniel Moisset wrote: On 21 May 2018 at 12:05, Rhodri James wrote: with my usual use cases.  What I normally want is the Python equivalent of:    while ((v = get_something()) != INCONVENIENT_SENTINEL) do_something(v); Tha

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Mike Miller
On 2018-05-21 05:22, Juancarlo Añez wrote: > This is a good summary of the choices. I think the second one is a good compromise. More elegant, yet avoiding the problems with assignment-expressions available everywhere. It is true that := handles more (perhaps less-common) use cases, but s

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Mike Miller
To clarify there were three main criteria, and one minor. Newer, popular/becoming industry standard, and designed to address shortcomings in previous generations. Finally, the limit of my energy when already working on a project. I also should have provided the link to the previous discussio

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Carl Smith
> > for v in iter(get_something, INCOVENIENT_SENTINEL): > do_something(v) > > There are many ways round my use case, all of them inelegant. That has to > be one of the less comprehensible alternatives. In for-loops (because they include an assignment already) we can improve this with more i

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Rhodri James
On 21/05/18 13:22, Juancarlo Añez wrote: while ((v = get_something()) != INCONVENIENT_SENTINEL) do_something(v); The current pattern in Python would be something like: v = get_something() while v != INCONVENIENT_SENTINEL: do_something(v) v = get_something() Actually mo

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Rhodri James
On 21/05/18 12:29, Daniel Moisset wrote: On 21 May 2018 at 12:05, Rhodri James wrote: Thanks for the analysis, but I'm afraid I must disagree with your recommendation. It was the thought I first had when Chris came out with his first draft of the PEP several months ago, but it's not enough t

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Carl Smith
Sorry, hit send by accident. I meant to say: do_something(v) *if* v != INCONVENIENT_SENTINEL *else break* -- Carl Smith carl.in...@gmail.com On 21 May 2018 at 13:37, Carl Smith wrote: > v = get_something() > > while v != INCONVENIENT_SENTINEL: > > do_something(v) > > v = get_someth

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Carl Smith
v = get_something() while v != INCONVENIENT_SENTINEL: do_something(v) v = get_something() I'd personally go with: while True: v = get_something() if v != INCONVENIENT_SENTINEL: break do_something(v) But it's not much different. I'd really like to be ab

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Juancarlo Añez
> while ((v = get_something()) != INCONVENIENT_SENTINEL) > do_something(v); > The current pattern in Python would be something like: v = get_something() while v != INCONVENIENT_SENTINEL: do_something(v) v = get_something() With "as" allowed in "while", they pattern might be: w

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Matt Arcidy
On Mon, May 21, 2018, 03:58 Rhodri James wrote: > On 20/05/18 06:19, Matt Arcidy wrote: > > On Sat, May 19, 2018, 11:07 Kirill Balunov > wrote: > > > >> > >> > >> I think I have a very strong argument "why are not others valid" - > Because > >> already three months have passed and among 1300+ me

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Daniel Moisset
On 21 May 2018 at 12:05, Rhodri James wrote: > > Thanks for the analysis, but I'm afraid I must disagree with your > recommendation. It was the thought I first had when Chris came out with > his first draft of the PEP several months ago, but it's not enough to cope > with my usual use cases. Wh

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Rhodri James
On 19/05/18 01:54, Mike Miller wrote: In short, extend the "if/elif", "while", and comprehension to:     if pattern.search(data) as match:     …     while read_next_item() as value:     … Thanks for the analysis, but I'm afraid I must disagree with your recommendation. It was th

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-21 Thread Rhodri James
On 20/05/18 06:19, Matt Arcidy wrote: On Sat, May 19, 2018, 11:07 Kirill Balunov wrote: I think I have a very strong argument "why are not others valid" - Because already three months have passed and among 1300+ messages there was not a single real example where assignment expression would b

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Juancarlo Añez
> > print(child_pid) # child_pid is undefined > > Why on earth would it be undefined? > Indeed, users would expect the new uses of "as" to behave as the previous ones. The problem is that "with" and "except" do things differently: In [*1*]: *import* *os* In [*2*]: *with* open(os.path.expandus

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Tim Peters
[Tim, on Rebol/Red] >> >> x: 12 y: 13 >> == 13 >> >> [x y] >> == [x y] >> >> >> >> do [x y] >> == 13 [Greg Ewing ] > How does scoping work? If you pass a block to a function > which evaluates it, how are names in the block resolved? Too involved, but basically a form of lexical scoping. Rebol st

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Steven D'Aprano
On Sun, May 20, 2018 at 10:57:39AM -0700, Mike Miller wrote: > You seem determined to throw out requirements when it suits. One of which > was for newer languages. YOU are the one who changed the requirements: first you said "newer languages", then you changed it to industry standard. I showed

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Steven D'Aprano
On Sun, May 20, 2018 at 02:53:46PM -0400, Juancarlo Añez wrote: > This shouldn't be: > > if os.fork() as child_pid: > parent(child_pid) > else: >child() > > print(child_pid) # child_pid is undefined Why on earth would it be undefined? Anyway, if you want to propose an alternative to

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Greg Ewing
Tim Peters wrote: x: 12 y: 13 == 13 [x y] == [x y] do [x y] == 13 How does scoping work? If you pass a block to a function which evaluates it, how are names in the block resolved? -- Greg ___ Python-ideas mailing list Python-ideas@python.org htt

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Tim Peters
[Tim] >> I was an early REBOL user, and my head still hurts ;-) It was ... >> different, for sure. [Steven D'Aprano ] > Yeah, to me it looks more like a prefix version of Forth than Lisp. > Complete with "anything can be a name": The example I gave just strung "words" together, but just as funda

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Matt Arcidy
Anyone can trivially construct a scope that limits applicable cases to support a specific point. This thread is pointless without full context. On Sun, May 20, 2018, 11:05 Mike Miller wrote: > For more background, this is the thread that inspired this one: > > https://mail.python.org/piper

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Juancarlo Añez
> What would be the benefit of adding the "as child_pid" syntax? The > full assignment expression syntax completely covers all the jobs that > you can do with a capturing if statement. > > The "as" syntax over "if" and "while" may go in with all the restrictions and caveats already discussed. The

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Mike Miller
For more background, this is the thread that inspired this one: https://mail.python.org/pipermail/python-dev/2018-April/153071.html -Mike ___ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas C

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Mike Miller
You seem determined to throw out requirements when it suits. One of which was for newer languages. While this thread's original post was not so specific on that, in a previous post (I believe you read) defined that as created in the "last decade or so". The ones created to address shortcoming

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Chris Angelico
On Mon, May 21, 2018 at 1:19 AM, Juancarlo Añez wrote: > IMPORTANT NOTE: > > Enabling "as" in "if" and "while" doesn't have to be at the expense of some > form of assignment expression. We've been having this discussion as if has > to be either one or the other, and there's no reason we can't hav

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Juancarlo Añez
On Sun, May 20, 2018 at 1:35 AM, Steven D'Aprano wrote: > > but maybe when languages are weird enough they all look the same :-) > > https://www.dreamsongs.com/WorseIsBetter.html Look at what happened with PERL... IMPORTANT NOTE: Enabling "as" in "if" and "while" doesn't have to be at the ex

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-20 Thread Greg Ewing
Steven D'Aprano wrote: Yeah, to me it looks more like a prefix version of Forth than Lisp. Throf? -- Greg ___ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/p

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Steven D'Aprano
On Sun, May 20, 2018 at 12:21:16AM -0500, Tim Peters wrote: > I was an early REBOL user, and my head still hurts ;-) It was ... > different, for sure. [...] Yeah, to me it looks more like a prefix version of Forth than Lisp. Complete with "anything can be a name": > Yup! "i1+2=3*88" is a vari

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Tim Peters
[Steven D'Aprano ] > ... > Red (2011) > ... > ... claims to be nearly identical to Rebol. > > Wikipedia describes Rebol (and presumably Red) as not having either > expressions or statements in usual sense. Based on my reading, it is > kinda-sorta like Forth except without the stack or the postfix s

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Matt Arcidy
On Sat, May 19, 2018, 11:07 Kirill Balunov wrote: > > > I think I have a very strong argument "why are not others valid" - Because > already three months have passed and among 1300+ messages there was not a > single real example where assignment expression would be convenient or > useful outside

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Chris Angelico
On Sun, May 20, 2018 at 11:43 AM, Steven D'Aprano wrote: > Out of those industry standard languages (as ranked by TIOBE, other > methodology may result in other rankings) we find: > > 8/12 have some form of assignment expressions; > (Java, C, C++, C#, PHP, Javascript, Ruby, R) > > 4/12 do not (Pyt

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Steven D'Aprano
On Sat, May 19, 2018 at 04:28:10PM -0700, Mike Miller wrote: > > On 2018-05-19 06:41, Steven D'Aprano wrote: > >Details follow below. > > Thanks for this, had some more time to read it more closely. Correct me if > I'm probably wrong, but most of these are not used by many. Except perhaps: Ac

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Mike Miller
On 2018-05-19 16:00, Chris Angelico wrote: But you can't put a comparison after the assignment, if it's part of the syntax of the 'if' statement. That's not how grammar works. So you have two options: either the ONLY thing you can capture is the condition value (which you already know to be trut

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Mike Miller
On 2018-05-19 06:41, Steven D'Aprano wrote: Details follow below. Thanks for this, had some more time to read it more closely. Correct me if I'm probably wrong, but most of these are not used by many. Except perhaps: - Typescript, which is constrained by a compatibility goal with JavaScri

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Chris Angelico
On Sun, May 20, 2018 at 8:56 AM, Mike Miller wrote: > > On 2018-05-18 19:14, Chris Angelico wrote: >> >> Yes, largely because it's insufficient for all but a small handful of >> situations. I mentioned that in the previous email. > > > I'd argue that they are the bulk of occurrences, that's why th

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Mike Miller
On 2018-05-18 19:14, Chris Angelico wrote: Yes, largely because it's insufficient for all but a small handful of situations. I mentioned that in the previous email. I'd argue that they are the bulk of occurrences, that's why they've been chosen as the compromise in those languages. Once the

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Guido van Rossum
On Sat, May 19, 2018 at 9:40 AM, Mike Miller wrote: > > On 2018-05-19 06:41, Steven D'Aprano wrote: > >> Thanks for writing up the summary, but you have picked a very narrow >> subset of new languages. One might even say a biased subset. How about >> these new languages? >> > > Certainly. I chos

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Mike Miller
On 2018-05-18 18:10, Chris Angelico wrote: The bit that you tag on as an afterthought is actually critically important here. You have two options: 1) The 'as' is part of the syntax of the 'if' and 'while' statements; or This first choice appears the more conservative compromise that several h

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Mike Miller
Also meant to mention, I didn't pick them specifically in advance to match a goal. I was mildly surprised at their similar design on that front. -Mike ___ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/pytho

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Carl Smith
> JavaScript and PHP are abysmally designed languages, so we should > put little weight on any precedent they set. JavaScript has issues, due to its unique history, but to dismiss the entire language as too poorly designed to take seriously... Many clever people prefer JS to Python. -- Carl Smi

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Chris Angelico
On Sun, May 20, 2018 at 4:07 AM, Kirill Balunov wrote: > [Chris] > >> The bit that you tag on as an afterthought is actually critically >> important here. You have two options: >> 1) The 'as' is part of the syntax of the 'if' and 'while' statements; or >> 2) The 'as' is part of the definition of a

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Kirill Balunov
2018-05-19 3:54 GMT+03:00 Mike Miller : > Background: > > While the previous discussions about assignment-expressions (PEP 572) > (abbreviated AE below) have been raging one thing that was noticeable is > that > folks have been looking back to C for a solution. > > But how are newer languages solv

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Brendan Barnwell
On 2018-05-19 06:41, Steven D'Aprano wrote: TypeScript (2012) - a strict superset of Javascript, including assignment expressions Hack (2014) - a (not quite full) superset of PHP, including assignment expressions Overall your list is fair, and you're right that more languages could be consi

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Mike Miller
On 2018-05-19 06:41, Steven D'Aprano wrote: Thanks for writing up the summary, but you have picked a very narrow subset of new languages. One might even say a biased subset. How about these new languages? Certainly. I chose basically on whether it was well used (popular), I'd heard about it,

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Steven D'Aprano
Thanks for writing up the summary, but you have picked a very narrow subset of new languages. One might even say a biased subset. How about these new languages? Elixir, Elm, TypeScript, Hack, Julia, Perl6, Ring, LiveScript, Ballerina, Crystal, Opa, Red, Ceylon TL;DR At least 10 out of these 1

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-19 Thread Steven D'Aprano
On Sat, May 19, 2018 at 02:11:38PM +1200, Greg Ewing wrote: > Chris Angelico wrote: > >The 'as' syntax has been hammered out in great detail and is no longer > >recommended due to its negative interactions with existing constructs. > > Allowing it in arbitrary expressions has been ruled out on > t

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Chris Angelico
On Sat, May 19, 2018 at 4:12 PM, Greg Ewing wrote: > Paul Svensson wrote: > >> I don't quite get what's so subtle about it, am I missing something? >> >> The "with" keyword calls "__enter__", and "as" gives it a name. >> >> Just like "-x + y" is different from "-(x + y)", > > > I think the differe

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Greg Ewing
Paul Svensson wrote: I don't quite get what's so subtle about it, am I missing something? The "with" keyword calls "__enter__", and "as" gives it a name. Just like "-x + y" is different from "-(x + y)", I think the difference is that mentally one already tends to think of "with x as y" being

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Paul Svensson
On Sat, 19 May 2018, Greg Ewing wrote: Chris Angelico wrote: The 'as' syntax has been hammered out in great detail and is no longer recommended due to its negative interactions with existing constructs. Allowing it in arbitrary expressions has been ruled out on the grounds that the difference

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Nick Coghlan
On 19 May 2018 at 10:54, Mike Miller wrote: > Background: > > While the previous discussions about assignment-expressions (PEP 572) > (abbreviated AE below) have been raging one thing that was noticeable is > that > folks have been looking back to C for a solution. > > But how are newer languages

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Brendan Barnwell
On 2018-05-18 17:54, Mike Miller wrote: > Background: > > While the previous discussions about assignment-expressions (PEP 572) > (abbreviated AE below) have been raging one thing that was noticeable is that > folks have been looking back to C for a solution. > > But how are newer languages solv

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Chris Angelico
On Sat, May 19, 2018 at 12:11 PM, Greg Ewing wrote: > Chris Angelico wrote: >> >> The 'as' syntax has been hammered out in great detail and is no longer >> recommended due to its negative interactions with existing constructs. > > > Allowing it in arbitrary expressions has been ruled out on > the

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Greg Ewing
Chris Angelico wrote: The 'as' syntax has been hammered out in great detail and is no longer recommended due to its negative interactions with existing constructs. Allowing it in arbitrary expressions has been ruled out on the grounds that the difference between "with x as y:" and "with (x as y

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Juancarlo Añez
Conclusions > > > It appears assignment expressions are no longer the favored solution for > the > "assign and compare" use case. Not one of these five newer languages > supports > them fully, as the language generations from C to C# did. > > Of those that have recognized the use case

Re: [Python-ideas] Modern language design survey for "assign and compare" statements

2018-05-18 Thread Chris Angelico
On Sat, May 19, 2018 at 10:54 AM, Mike Miller wrote: > In short, extend the "if/elif", "while", and comprehension to: > > if pattern.search(data) as match: > … > > while read_next_item() as value: > … > > May be best to disallow multiple assignment/conditions for now, but u