220 40940 article Path: news.gmane.org!.POSTED!not-for-mail From: mihailnajdenov@gmail.com 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 09:02:32 -0800 (PST) Lines: 379 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/mixed; boundary="----=_Part_1320_788556904.1541869352385" X-Trace: blaine.gmane.org 1541869229 29130 195.159.176.226 (10 Nov 2018 17:00:29 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 10 Nov 2018 17:00:29 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCUJ3A7GRAPRBKM6TTPQKGQEZE6I33Y@isocpp.org Sat Nov 10 18:00:25 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yw1-f71.google.com ([209.85.161.71]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gLWcR-0007U1-Uk for gclcip-std-proposals@m.gmane.org; Sat, 10 Nov 2018 18:00:24 +0100 Original-Received: by mail-yw1-f71.google.com with SMTP id t205-v6sf4886911ywf.0 for ; Sat, 10 Nov 2018 09:02:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=Sbhee7VlhNT9CNRLgGG3tc9wPFhI9a8Q5Vk/Xty6BGM=; b=IwqCn1Mr1hEle8JUN6D+T3LtvfFY0ETHxxeWFnMeuoyRwzJ/6ZRzUmfUSSyn2Rl8qn U+TF6fm606Nk1uNlyVsw102Zi1v0ZVGQ3/25A073aiwf/E8YcVggxsroIzAihk4beH66 GYM9N3hbw9c1pZwhkhjhC/jKtQBfDDEM/+y36/ScDnPXoM+kjp1RUYZsigys3LNL4QXf E84xlpkmzOeyQgITRvS7Y8q7FJO4s7PYPem9cj1btn69/jHFzzIZm9J3ZBA3mTIRfd3L NH6gJC2q9n0y9g5GJ6ZUZS4bDlgLD6OAUkimW93F3wZJua5d3vJGVY/Q5jhT4W3Q0tr1 CtPg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=Sbhee7VlhNT9CNRLgGG3tc9wPFhI9a8Q5Vk/Xty6BGM=; b=lj3m3Um8/RNMRN2+zNoMWPsHRjayR9QR2dcbCDim86bHMfuk64sajvuH7/R055UiiZ KmKxqSLpbz/2KbtVJwjjewgWnVXXwujLvRBEtUTTG2kI+9006ruUrIXYL2MKiw5AoQkB ROdgmF/BIz+8pGRhkd3OEWG4w75Lpd23bE3rxUGQMpOEouprQOoekqYdje+uFBWtM5e9 AveKALLiHSqlBrsZgd9AZ6lO3psctEtw9ydZuhlwypaRNRhseyFbeNc84zIusss8Itot gt7FPwdShKo7J+O0V3fChu5CcgRtANJ/Wg4qo2FvUmsvNmx1u9cBH4SZdpkZT/RSc350 ThsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=Sbhee7VlhNT9CNRLgGG3tc9wPFhI9a8Q5Vk/Xty6BGM=; b=mZn125isASPEuylhbTaXG2M7gZB3eB2ekHtqr6yglW9Q1a1VeoZYOg2dS6EpiGhYQC q/HejJqljDm7gSBMnXUSyISoJ4bbyh5P2h1p9uZl2EteTSFptDHN7aZvS17gN71ZF8VA F7bV/08Dgh8OwoXzXp+2LjfDsHEBdzvTSumORj4rO+oOhZEgV7qq6XJqVtYXqVE9Qhrj AuVpQWr2zpRPUao36zhbE7ZTY/M6bsPV5LuDOb0FO6QB7llrWwFEwLcU6lUj+Yic9sNt dt9WZ+OhV//0aZ4Un6LnnzOudsC2zifZ1LZXdCxxpDamIFBjNJpAUFv7W4Dw2ATWahhw uSew== X-Gm-Message-State: AGRZ1gIwrHb8YNsUf7RdXxJHZrWuH2T+cLb+m2Fey9g7S9fIyRwOLmw2 I7B5srz0Txg0DpVEgy1xCUj86Q== X-Google-Smtp-Source: AJdET5cKQTmWL3V/EMqVAUvAIsXROVxAj8PU3Tk6+ynnzBDnqI2ykHj0EjE8vQ2yGT3N8786/Q7Kqg== X-Received: by 2002:a25:8503:: with SMTP id w3-v6mr6464523ybk.72.1541869354152; Sat, 10 Nov 2018 09:02:34 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a81:4b89:: with SMTP id y131-v6ls2493462ywa.12.gmail; Sat, 10 Nov 2018 09:02:33 -0800 (PST) X-Received: by 2002:a81:3196:: with SMTP id x144-v6mr154354ywx.1.1541869352854; Sat, 10 Nov 2018 09:02:32 -0800 (PST) In-Reply-To: X-Original-Sender: MihailNajdenov@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:40940 Archived-At: ------=_Part_1320_788556904.1541869352385 Content-Type: multipart/alternative; boundary="----=_Part_1321_1022228256.1541869352386" ------=_Part_1321_1022228256.1541869352386 Content-Type: text/plain; charset="UTF-8" On Saturday, November 10, 2018 at 5:28:37 PM UTC+2, Nicolas Lesser wrote: > > You're going to have a hard time because the committee doesn't like > iostreams and plans on replacing them with something else. > Are there any proposals in flight? I see Text Formating , but it does not include I/O (AFAICT) > > 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 wrote: > >> >> >> 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-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/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/f7bd155a-bcbf-49f0-ac34-f0628ccf50e1%40isocpp.org. ------=_Part_1321_1022228256.1541869352386 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Saturday, November 10, 2018 at 5:28:37 PM UTC+2= , Nicolas Lesser wrote:
You're going to have a hard time because the committee doesn= 't like iostreams and plans on replacing them with something else.

Are there any proposals in flight? I see = Text Formating=C2=A0, but it does not include I/O (AFAICT)=C2=A0<= /div>
=C2=A0

And I don't rea= lly see a problem with \n. Sure, it's a bit old-school, but it's cl= ear 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 <mihailn...@gmail.com wrote:


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


There are multiple problems with '\n= 9;

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.=C2=A0
The= fact there no C++ way to insert a new line (only a UNIX special character = way) is what I state an issue,=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<= br>
=C2=A0- the fact a char can be more the one, well, character
<= div>=C2=A0- 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").
=C2=A0
What do you mea= n, "what is used to end it"? 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 <&= lt; 255
=C2=A0 <&= lt; '\n';=C2=A0 =C2=A0 //< finish (magic)=C2=A0

Note that printf (and other languages) already use sp= ecial characters to modify the output, so having an '\n' is not abr= upt.

But C++ streams are different, having to spel= l out a special character is odd and unintuitive for a beginner and a desig= n deficiency in general.=C2=A0=C2=A0


=C2=A0

This screams some design flaw - we should be able to i= nsert a new lines the same way we modify the stream!
Yes, the way to do that is with '\n'.
=C2=A0=

<= div>On its own std::endl has the flaw that it does not obey the "do on= e thing" rule.
Once we deprecate it, this will shut down all= the naive tutorials/courses still teaching it as the default!=C2=A0
<= div>

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) wi= ll have a simple, correct,=C2=A0go-to option that models the syntax = already introduced (std::cout)!


On Friday, November 9, 20= 18 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=C2=A0iPad+41 79 432 23 32

On 8 Nov 2= 018, at 23:43, Hyman Rosen <hyman...@gmai= l.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 incompete= nt 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.=C2=A0 I have th= e feeling, completely unsupported
by evidence, that the iostreams design= ers thought manipulators were
really keen, and wanted to have one that w= ould 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/CAHSYqdYYZjeHHbRZ5bcHLYVsWfspwCeQ8oxE= DRbuJ8dqAtsX5A%40mail.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-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 &= 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/7da1f33f-c2c1-482f-8fc2-= c23a9767a5ec%40isocpp.org.

--
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 https://groups.google.= com/a/isocpp.org/d/msgid/std-proposals/f7bd155a-bcbf-49f0-ac34-f0628ccf50e1= %40isocpp.org.
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