220 40936 article Path: news.gmane.org!.POSTED!not-for-mail From: Brian Bi Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Can we have beginner friendly new line and deprecate std::endl? 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[209.85.220.41]) by mx.google.com with SMTPS id w15-v6sor4584757edb.5.2018.11.09.08.50.57 for (Google Transport Security); Fri, 09 Nov 2018 08:50:57 -0800 (PST) Received-SPF: pass (google.com: domain of bbi5291@gmail.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; X-Received: by 2002:a50:a8e5:: with SMTP id k92-v6mr3152700edc.2.1541782256235; Fri, 09 Nov 2018 08:50:56 -0800 (PST) In-Reply-To: X-Original-Sender: bbi5291@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=qJTpFLvF; spf=pass (google.com: domain of bbi5291@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=bbi5291@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:40936 Archived-At: --000000000000b43a27057a3e2773 Content-Type: text/plain; charset="UTF-8" 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. 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? > > 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-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/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/CAMmfjbOjpJvBWEke1z0XXnHXhjtEO_otNN5-jayGPwe3RHO0Rw%40mail.gmail.com. --000000000000b43a27057a3e2773 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Fri= , Nov 9, 2018 at 3:19 AM <mi= hailnajdenov@gmail.com> wrote:
There are multiple problems with '\n'

<= /div>
First - it is ultimately C ("way")
This mailing list is about C++, not Java, Rust, Swift, etc.
<= div>This is not an argument.

Second, when we introduce simple output to begin= ners, for which cout is actually good because of overloading,
whe= n using '\n' we have to introduce additional topics=C2=A0
= =C2=A0- the fact a char can be more the one, well, character
=C2= =A0- special magic characters
We also create asymmetry b/w what i= s used to start the output std::cout (an object), to modify it (hex) and wh= at is used to end it ("magic").
What do you mean, "what is used to end it"? A semicolon?
<= div>=C2=A0
<= br>
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'.
=C2=A0
<= blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px= #ccc solid;padding-left:1ex">

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 na= ive tutorials/courses still teaching it as the default!=C2=A0

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

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,=C2=A0go-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 stud= ents 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 <hyman...@gmail.com> wrote= :

=
On Thu, Nov 8, 2018 at 5:08 PM = Brian Bi <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 i= s portable whereas '\n' isn't.

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 unsuppor= ted
by evidence, that the iostreams designers thought manipulators were<= br>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.o= rg.
To view this discussion on the web visit https://groups.google.com/a/isocpp.org/= d/msgid/std-proposals/CAHSYqdYYZjeHHbRZ5bcHLYVsWfspwCeQ8oxEDRbuJ8dqAtsX5A%4= 0mail.gmail.com.

--
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-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/b49f4c85-816b-= 4b35-851d-407061a8ef9f%40isocpp.org.


--
Brian Bi

--
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-proposa= ls+unsubscribe@isocpp.org.
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/CAMmfjbOjpJvBWEke= 1z0XXnHXhjtEO_otNN5-jayGPwe3RHO0Rw%40mail.gmail.com.
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