Why prefer != over <> for Python 3.0?

[Colin J. Williams]

Re: Why prefer != over &lt;&gt; for Python 3.0?

kwitters@telene t.be wrote:

I don't know if this is the right place to discuss the death of <in
Python 3.0, or if there have been any meaningful discussions posted
before (hard to search google with '<>' keyword), but why would anyone
prefer the comparison operator != over <>???
>
I've written an article about it to try and save this nice "is not
equal" operator, located at http://dewitters.koonsolo.com/python_neq.html
>
Please set it straight in 3.0, and if not, convince me with a good
reason of doing so, so that I can live with it and don't have to spend
the rest of my life in 2.x ;).

Algol 60 had no such operator.
Algol-W had (not)= [(not) was a negative
symbol, not on our current keyboard]
Simula 67 introduced <>
Pascal uses <[Pascal is still
available - http://www.freepascal.org/]
C uses !=
[http://cermics.enpc.fr/~ts/C/CONCEPT...ions.html#rel]

I prefer <but I feel that it's better
not to have two ways of representing
not equal.

The powers that be have chosen !=. I
accept this on the grounds that current
languages seem to have nade that choice.

Colin W.

[MRAB]

Re: Why prefer != over &lt;&gt; for Python 3.0?

On Mar 30, 6:35 am, "Gabriel Genellina" <gagsl-...@yahoo.com.a r>
wrote:

En Sun, 30 Mar 2008 02:11:33 -0300, hdante <hda...@gmail.c omescribió:
>

BTW, my opinion is that it's already time that programmer editors
have input methods advanced enough for generating this:

>

if x ≠ 0:
∀y ∈ s:
if y ≥ 0: f1(y)
else: f2(y)

>
Fine if you have the right keyboard... Try to write APL with a standard
keyboard :)
>

There was a version of APL for the Sinclair QL which replaced the
standard APL symbols with keywords.

[Dan Bishop]

Re: Why prefer != over &lt;&gt; for Python 3.0?

On Mar 30, 5:40 am, Torsten Bronger <bron...@physik .rwth-aachen.de>
wrote:

Hallöchen!
>
Bjoern Schliessmann writes:

Lie wrote:

>

Ah yes, that is also used (I completely forgot about that one, my
math's aren't that sharp anymore) and I think it's used more
frequently than ><.

>

Where did you read that (I mean, which country)? I've never seen
this sign in any german or english book on
mathematics/physics/engineering I saw.

>
Maybe he means "≷".
>

but my argument was that no math book use != or <(except in
math for programmers).

>

That's true. Personally, I don't ever use "a!=b" in favor of "not
a==b".

>
As a side note, I've always found == rather ugly. I'd prefer to
have = for both purposes.

The earliest versions of Python *did* use = for both purposes.

The constructs that wouldn't work anymore
are rare as far as I can see (and possibly there are even
workarounds).

The construct a = b == c could be rewritten as a = (b = c).

[Lie]

Re: Why prefer != over &lt;&gt; for Python 3.0?

On Mar 30, 7:48 pm, Bjoern Schliessmann <usenet-
mail-0306.20.chr0n.. .@spamgourmet.c omwrote:

Torsten Bronger wrote:

Maybe he means "?".

>
Haven't seen this either, nor do I think it's the same than "<>".
From afar, it looks more like "><".

Actually I meant an X-like symbol that is made not by crossing but by

><. I retracted saying it is the standard, now that I think about it

the last time I saw >< was in elementary school (although it stuck on
my head better than a crossed =, which I first met in high school).

But this does more look like
South Park style shut eyes than an operator. :)

lol, I agree, it looks too much like closed eye smiley. Forums might
automatically convert them to graphic smileys so it is obviously a bad
choice if it is to be used.

[Lie]

Re: Why prefer != over &lt;&gt; for Python 3.0?

On Mar 30, 5:25 pm, Bjoern Schliessmann <usenet-
mail-0306.20.chr0n.. .@spamgourmet.c omwrote:

Lie wrote:

Ah yes, that is also used (I completely forgot about that one, my
math's aren't that sharp anymore) and I think it's used more
frequently than ><.

>
Where did you read that (I mean, which country)? I've never seen
this sign in any german or english book on
mathematics/physics/engineering I saw.

It was in my elementary school at Indonesia (FYI, it is also used as
antonym sign in languages (at least in my country)). And I think I'll
retract that claim, >< wasn't the standard, a crossed = is the
standard (btw, with a little imagination != looks like a crossed =).

[Gabriel Genellina]

Re: Why prefer != over &lt;&gt; for Python 3.0?

En Sun, 30 Mar 2008 11:10:20 -0300, MRAB <google@mrabarn ett.plus.com>
escribió:

On Mar 30, 6:35 am, "Gabriel Genellina" <gagsl-...@yahoo.com.a r>
wrote:

>En Sun, 30 Mar 2008 02:11:33 -0300, hdante <hda...@gmail.c omescribió:
>>

BTW, my opinion is that it's already time that programmer editors
have input methods advanced enough for generating this:

>>

if x ≠ 0:
∀y ∈ s:
if y ≥ 0: f1(y)
else: f2(y)

>>
>Fine if you have the right keyboard... Try to write APL with a standard
>keyboard :)
>>

There was a version of APL for the Sinclair QL which replaced the
standard APL symbols with keywords.

Wow, APL on 8 bits?
Now there is (or perhaps there was) J, a reincarnation of APL by Iverson
himself that uses ASCII characters only.

--
Gabriel Genellina

[hdante]

Re: Why prefer != over &lt;&gt; for Python 3.0?

On Mar 30, 9:45 am, Bjoern Schliessmann <usenet-
mail-0306.20.chr0n.. .@spamgourmet.c omwrote:

hdante wrote:

BTW, my opinion is that it's already time that programmer editors
have input methods advanced enough for generating this:

>
Could you please list some that do, and are also convenient?

AFAICT there's none. This should be easy to implement on emacs, or in
SCIM.

>
Regards,
>
Björn
>
--
BOFH excuse #288:
>
Hard drive sleeping. Let it wake up on it's own...

[Torsten Bronger]

Re: Why prefer != over &lt;&gt; for Python 3.0?

Hallöchen!

hdante writes:

On Mar 30, 9:45 am, Bjoern Schliessmann <usenet-
mail-0306.20.chr0n.. .@spamgourmet.c omwrote:
>

>hdante wrote:
>>

>>BTW, my opinion is that it's already time that programmer
>>editors have input methods advanced enough for generating this:

>>
>Could you please list some that do, and are also convenient?

>
AFAICT there's none. This should be easy to implement on emacs,

It *is* implemented in Emacs. You can even choose from many input
methods, optimised for differend areas/languages.

Tschö,
Torsten.

--
Torsten Bronger, aquisgrana, europa vetus
Jabber ID: bronger@jabber. org
(See http://ime.webhop.org for further contact info.)

[hdante]

Re: Why prefer != over &lt;&gt; for Python 3.0?

On Mar 30, 6:08 pm, Torsten Bronger <bron...@physik .rwth-aachen.de>
wrote:

Hallöchen!
>
hdante writes:

On Mar 30, 9:45 am, Bjoern Schliessmann <usenet-
mail-0306.20.chr0n.. .@spamgourmet.c omwrote:

>

hdante wrote:

>

>BTW, my opinion is that it's already time that programmer
>editors have input methods advanced enough for generating this:

>

Could you please list some that do, and are also convenient?

>

AFAICT there's none. This should be easy to implement on emacs,

>
It *is* implemented in Emacs. You can even choose from many input
methods, optimised for differend areas/languages.

I mean creating an input method specific for programming languages,
not using the TeX one.

>
Tschö,
Torsten.
>
--
Torsten Bronger, aquisgrana, europa vetus
Jabber ID: bron...@jabber. org
(Seehttp://ime.webhop.orgf or further contact info.)

[Bjoern Schliessmann]

Re: Why prefer != over &lt;&gt; for Python 3.0?

Torsten Bronger wrote:

Emacs is generally not regarded as being convenient, however, it
has very strong input methods. I type "\gtrless" and get "?",
or "\forall" and get "?".

I wonder where the point of this is. :) Why use fancy unicode chars
if they're not better to read (apart from not being readable with
every font) and require at least the same amount of keypresses?

Regards,


Björn

--
BOFH excuse #123:

user to computer ratio too high.

[Torsten Bronger]

Re: Why prefer != over &lt;&gt; for Python 3.0?

Hallöchen!

Bjoern Schliessmann writes:

Torsten Bronger wrote:
>

>Emacs is generally not regarded as being convenient, however, it
>has very strong input methods. I type "\gtrless" and get "?", or
>"\forall" and get "?".

Doesn't KNode support UTF-8?

I wonder where the point of this is. :) Why use fancy unicode
chars if they're not better to read (apart from not being readable
with every font) and require at least the same amount of
keypresses?

Who wants to minimize the number of keypresses? We're not Perl
after all. ;-)

As a general rule of thumb in typography, more glyph forms increase
readability. APL is not readable at all but this is due to its
syntax I suppose. I find hdante's excerpt very readable.

The only reason why we don't use those special characters is that
they aren't ASCII. While ∀ or ∈ are questionable because Python
prefers English words instead of scientific symbols, ≠ or ≤ would be
certainly more legible than != or <=. But they are not ASCII, so
there is no net benefit.

However, I'm quite sure that when Unicode has arrived almost
everywhere, some languages will start considering such characters in
their core syntax. Python 3.0 allows for Unicode letters in
identifiers, and there's still room for improvement.

Tschö,
Torsten.

--
Torsten Bronger, aquisgrana, europa vetus
Jabber ID: bronger@jabber. org
(See http://ime.webhop.org for further contact info.)

[Paul Rubin]

Re: Why prefer != over &lt;&gt; for Python 3.0?

Torsten Bronger <bronger@physik .rwth-aachen.dewrites :

However, I'm quite sure that when Unicode has arrived almost
everywhere, some languages will start considering such characters in
their core syntax. Python 3.0 allows for Unicode letters in
identifiers, and there's still room for improvement.

I agree. What's the codepoint for lower case lambda?

[Bjoern Schliessmann]

Re: Why prefer != over &lt;&gt; for Python 3.0?

Torsten Bronger wrote:

Doesn't KNode support UTF-8?

Well, it should, but automatic encoding detection doesn't always
seem to work (or does it even have one?). I'm looking for a
different (faster) newsreader anyway.

Who wants to minimize the number of keypresses? We're not Perl
after all. ;-)

Sure, but I also don't want to enter fancy unicode operators. I'm
using Python on some computers that even don't support unicode.

However, I'm quite sure that when Unicode has arrived almost
everywhere, some languages will start considering such characters
in their core syntax.

This should be the time when there are widespread quasi-standardised
input methods for those characters.

Regards,


Björn

--
BOFH excuse #154:

You can tune a file system, but you can't tune a fish (from most
tunefs man pages)

[Terry Reedy]

Re: Why prefer != over &lt;&gt; for Python 3.0?


"Bjoern Schliessmann" <usenet-mail-0306.20.chr0n0s s@spamgourmet.c omwrote
in message news:65c0bfF2ff ipiU1@mid.indiv idual.net...
| However, I'm quite sure that when Unicode has arrived almost
| everywhere, some languages will start considering such characters
| in their core syntax.
|
| This should be the time when there are widespread quasi-standardised
| input methods for those characters.

C has triglyphs for keyboards missing some ASCII chars. != and <= could
easily be treated as diglyphs for the corresponding chars. In a sense they
are already, it is just that the real things are not allowed ;=).

[Gabriel Genellina]

Re: Why prefer != over &lt;&gt; for Python 3.0?

En Mon, 31 Mar 2008 16:17:39 -0300, Terry Reedy <tjreedy@udel.e du>
escribió:

"Bjoern Schliessmann" <usenet-mail-0306.20.chr0n0s s@spamgourmet.c om>
wrote
in message news:65c0bfF2ff ipiU1@mid.indiv idual.net...
| However, I'm quite sure that when Unicode has arrived almost
| everywhere, some languages will start considering such characters
| in their core syntax.
|
| This should be the time when there are widespread quasi-standardised
| input methods for those characters.
>
C has triglyphs for keyboards missing some ASCII chars. != and <= could
easily be treated as diglyphs for the corresponding chars. In a sense
they
are already, it is just that the real things are not allowed ;=).

I think it should be easy to add support for ≠≤≥ and even λ, only the
tokenizer has to be changed.

--
Gabriel Genellina