220 40938 article Path: news.gmane.org!.POSTED!not-for-mail From: Nicolas Lesser Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Can we have beginner friendly new line and deprecate std::endl? Date: Sat, 10 Nov 2018 07:28:24 -0800 Lines: 329 Approved: news@gmane.org Message-ID: References: <7da1f33f-c2c1-482f-8fc2-c23a9767a5ec@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="00000000000008cec8057a511f7d" X-Trace: blaine.gmane.org 1541863591 17838 195.159.176.226 (10 Nov 2018 15:26:31 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 10 Nov 2018 15:26:31 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDXKNLEUTADRBI7STPPQKGQEYMXYKQA@isocpp.org Sat Nov 10 16:26:27 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oi1-f200.google.com ([209.85.167.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gLV9W-0004VH-TD for gclcip-std-proposals@m.gmane.org; Sat, 10 Nov 2018 16:26:27 +0100 Original-Received: by mail-oi1-f200.google.com with SMTP id y73-v6sf2847790oie.13 for ; Sat, 10 Nov 2018 07:28:37 -0800 (PST) ARC-Seal: i=2; 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[209.85.220.41]) by mx.google.com with SMTPS id q125-v6sor4868062oia.48.2018.11.10.07.28.35 for (Google Transport Security); Sat, 10 Nov 2018 07:28:35 -0800 (PST) Received-SPF: pass (google.com: domain of blitzrakete@gmail.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; X-Received: by 2002:aca:d4d7:: with SMTP id l206-v6mr7530862oig.307.1541863715162; Sat, 10 Nov 2018 07:28:35 -0800 (PST) In-Reply-To: <7da1f33f-c2c1-482f-8fc2-c23a9767a5ec@isocpp.org> X-Original-Sender: blitzrakete@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=IYnlYdIY; spf=pass (google.com: domain of blitzrakete@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=blitzrakete@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:40938 Archived-At: --00000000000008cec8057a511f7d Content-Type: text/plain; charset="UTF-8" You're going to have a hard time because the committee doesn't like iostreams and plans on replacing them with something else. And I don't really see a problem with \n. Sure, it's a bit old-school, but it's clear and almost every language uses it. If you're programming you'll going to have to learn \n eventually. On Sat, Nov 10, 2018, 7:24 AM > > On Friday, November 9, 2018 at 6:50:59 PM UTC+2, Brian Bi wrote: >> >> >> >> On Fri, Nov 9, 2018 at 3:19 AM wrote: >> >>> There are multiple problems with '\n' >>> >>> First - it is ultimately C ("way") >>> >> This mailing list is about C++, not Java, Rust, Swift, etc. >> This is not an argument. >> > > There is some sort of miscommunication. > The fact there no C++ way to insert a new line (only a UNIX special > character way) is what I state an issue, > considering the rest of the API > > >> >> Second, when we introduce simple output to beginners, for which cout is >>> actually good because of overloading, >>> when using '\n' we have to introduce additional topics >>> - the fact a char can be more the one, well, character >>> - special magic characters >>> We also create asymmetry b/w what is used to start the output std::cout >>> (an object), to modify it (hex) and what is used to end it ("magic"). >>> >> > >> What do you mean, "what is used to end it"? A semicolon? >> > > std::cout //< start > << 12.f > << ' ' > << std::hex //< modify > << 255 > << '\n'; //< finish (magic) > > Note that printf (and other languages) already use special characters to > modify the output, so having an '\n' is not abrupt. > > But C++ streams are different, having to spell out a special character is > odd and unintuitive for a beginner and a design deficiency in general. > > > >> >>> >>> This screams some design flaw - we should be able to insert a new lines >>> the same way we modify the stream! >>> >> Yes, the way to do that is with '\n'. >> >> >>> >>> On its own std::endl has the flaw that it does not obey the "do one >>> thing" rule. >>> Once we deprecate it, this will shut down all the naive >>> tutorials/courses still teaching it as the default! >>> >>> >>> As for std::newline, we have options - >>> >>> std::nl //< even a beginner can "read" it >>> std::newl //< orthogonal to endl >>> std::br //< why not at this point! >>> std::brl >>> std::bl >>> >>> Geeks can still use `\n`, but a beginner (and a teacher) will have a >>> simple, *correct, *go-to option that models the syntax already >>> introduced (std::cout)! >>> >>> >>> On Friday, November 9, 2018 at 8:22:26 AM UTC+2, PeterSommerlad wrote: >>>> >>>> So the better way is do better teaching. I show my students that they >>>> should not use endl, except when they need it. >>>> >>>> Sent from Peter Sommerlad's iPad >>>> +41 79 432 23 32 >>>> >>>> On 8 Nov 2018, at 23:43, Hyman Rosen wrote: >>>> >>>> On Thu, Nov 8, 2018 at 5:08 PM Brian Bi wrote: >>>> >>>>> I think the reason why novices use std::endl is that they're under the >>>>> impression (no doubt perpetuated by incompetent educators) that std::endl >>>>> is portable whereas '\n' isn't. >>>>> >>>> >>>> I think novices use std::endl because that's how C++ formatted I/O >>>> was presented for ages. I have the feeling, completely unsupported >>>> by evidence, that the iostreams designers thought manipulators were >>>> really keen, and wanted to have one that would always get used. >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "ISO C++ Standard - Future Proposals" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to std-proposal...@isocpp.org. >>>> To post to this group, send email to std-pr...@isocpp.org. >>>> To view this discussion on the web visit >>>> https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/CAHSYqdYYZjeHHbRZ5bcHLYVsWfspwCeQ8oxEDRbuJ8dqAtsX5A%40mail.gmail.com >>>> >>>> . >>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "ISO C++ Standard - Future Proposals" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to std-proposal...@isocpp.org. >>> To post to this group, send email to std-pr...@isocpp.org. >>> To view this discussion on the web visit >>> https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/b49f4c85-816b-4b35-851d-407061a8ef9f%40isocpp.org >>> >>> . >>> >> >> >> -- >> *Brian Bi* >> > -- > You received this message because you are subscribed to the Google Groups > "ISO C++ Standard - Future Proposals" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to std-proposals+unsubscribe@isocpp.org. > To post to this group, send email to std-proposals@isocpp.org. > To view this discussion on the web visit > https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/7da1f33f-c2c1-482f-8fc2-c23a9767a5ec%40isocpp.org > > . > -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/CALmDwq1wq9pKv3Esy4AXepnSMotfXTwoJ3BUQwHdmJza2gWP_Q%40mail.gmail.com. --00000000000008cec8057a511f7d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
You're going to have a hard time because the committe= e doesn't like iostreams and plans on replacing them with something els= e.

And I don't really see = a problem with \n. Sure, it's a bit old-school, but it's clear and = almost every language uses it. If you're programming you'll going t= o have to learn \n eventually.

On Sat, Nov 10, 2018, 7:24 AM <mihailnajdenov@gmail.com wrote:


On Friday, November 9, 2018 at= 6:50:59 PM UTC+2, Brian Bi wrote:


On Fr= i, Nov 9, 2018 at 3:19 AM <mihailn...@gma= il.com> wrote:
There are multiple problems with '\n'

First = - it is ultimately C ("way")
This ma= iling list is about C++, not Java, Rust, Swift, etc.
This is not = an argument.

There is som= e sort of miscommunication.=C2=A0
The fact there no C++ way to in= sert a new line (only a UNIX special character way) is what I state an issu= e,=C2=A0
considering the rest of the API=C2=A0
=C2=A0

Second, when we introduce simple output to beginners, for which cout = is actually good because of overloading,
when using '\n' = we have to introduce additional topics=C2=A0
=C2=A0- the fact a cha= r can be more the one, well, character
=C2=A0- special magic char= acters
We also create asymmetry b/w what is used to start the out= put std::cout (an object), to modify it (hex) and what is used to end it (&= quot;magic").
<= div>=C2=A0
What do you mean, "what is used to end i= t"? A semicolon?

std::cout=C2=A0 =C2=A0 =C2=A0//<= start=C2=A0
=C2=A0 = << 12.f=C2=A0
= =C2=A0 << ' '=C2=A0
=C2=A0 << std::hex //< modify
=C2=A0 << 255
=C2=A0 << '\n';=C2=A0 =C2=A0= //< finish (magic)=C2=A0

Note tha= t printf (and other languages) already use special characters to modify the= output, so having an '\n' is not abrupt.

= But C++ streams are different, having to spell out a special character is o= dd and unintuitive for a beginner and a design deficiency in general.=C2=A0= =C2=A0


=C2=A0

This scre= ams some design flaw - we should be able to insert a new lines the same way= we modify the stream!
Yes, the way to d= o that is with '\n'.
=C2=A0

On its own std::endl has t= he flaw that it does not obey the "do one thing" rule.
= Once we deprecate it, this will shut down all the naive tutorials/courses s= till teaching it as the default!=C2=A0


<= div>As for std::newline, we have options -=C2=A0

<= font face=3D"courier new, monospace">std::nl //< even a beginner can &qu= ot;read" it
std= ::newl //< orthogonal to endl
std::br //< why not at this point!
std::brl
std::bl

Geeks can still= use `\n`, but a beginner (and a teacher) will have a simple, correct,= =C2=A0go-to option that models the syntax already introduced (std::cout= )!


On Friday, November 9, 2018 at 8:22:26 AM UTC+2, Peter= Sommerlad wrote:
S= o the better way is do better teaching. I show my students that they should= not use endl, except when they need it.

Sent from = Peter Sommerlad's=C2=A0iPad
+41 79 432 23 32

On 8 Nov 2018, at 23:43, Hyman Rosen &l= t;hyman...@gmail.com> wrote:

<= /div>
On Thu, Nov 8, 2018 at 5:08 PM Brian Bi &= lt;bbi...@gmail.com> wrote:
I think the reason why novices use std::endl is that they're under the= impression (no doubt perpetuated by incompetent educators) that std::endl = is portable whereas '\n' isn't.
<= div>
I think novices use std::endl because that's how C++ formatted = I/O
was presented for ages.=C2=A0 I have the feeling, completely unsuppo= rted
by evidence, that the iostreams designers thought manipulators were=
really keen, and wanted to have one that would always get used.

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposal...@isocpp.org.
To post to this group, send email to std-pr.= ...@isocpp.org.
To view this discussion on the web visit https://groups.google.com/a/= isocpp.org/d/msgid/std-proposals/CAHSYqdYYZjeHHbRZ5bcHLYVsWfspwCeQ8oxEDRbuJ= 8dqAtsX5A%40mail.gmail.com.

--
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To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposal...@isocpp.org.
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To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/= std-proposals/b49f4c85-816b-4b35-851d-407061a8ef9f%40isocpp.org.


--
Brian Bi=

--
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--
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To post to this group, send email to std-proposals@isocpp.org.
To view this discussion on the web visit htt= ps://groups.google.com/a/isocpp.org/d/msgid/std-proposals/CALmDwq1wq9pKv3Es= y4AXepnSMotfXTwoJ3BUQwHdmJza2gWP_Q%40mail.gmail.com.
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