220 18092 <7a01ca3b-ad4a-49c1-b1cc-ce2b9fa5ff84@isocpp.org> article Path: news.gmane.org!not-for-mail From: Matthew Fioravante Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Parsing Numbers Date: Wed, 20 May 2015 20:18:42 -0700 (PDT) Lines: 231 Approved: news@gmane.org Message-ID: <7a01ca3b-ad4a-49c1-b1cc-ce2b9fa5ff84@isocpp.org> References: <555CDDEF.8000002@gmx.net> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_4836_1788312111.1432178322075" X-Trace: ger.gmane.org 1432178326 21948 80.91.229.3 (21 May 2015 03:18:46 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 21 May 2015 03:18:46 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDELF54RTIGRBE456WVAKGQEKDU6Z4Y@isocpp.org Thu May 21 05:18:46 2015 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ig0-f197.google.com ([209.85.213.197]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YvH0O-0008Ni-IE for gclcip-std-proposals@m.gmane.org; Thu, 21 May 2015 05:18:44 +0200 Original-Received: by igbri1 with SMTP id ri1sf112544799igb.2 for ; Wed, 20 May 2015 20:18:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :content-type:x-original-sender:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe; bh=ai9s7VXcdayxpYO3zEyd5SR8wnNiLNGS9HyWEVIKRUw=; b=SKq3laXgwk/yIrFYRjNZJ7qwW2vpeO7JlSiL4dpHEgsOfgPt3+QLY07qUlA8lrRD5X 76V+KBLwrTS0/kR70el/KDLM52+OdUqFQBwv3wP192ByZheET4rk3pEMLT0ak8cv2UK5 OfE31e7kLpX64QaTxjBdMx8Vze7tPr4LtDx6/hvZ8B7UNJbIorIK2XfBhPYZK5pacuDr +DTZYrcNmPofs+nqUlNy3ONPObSYKtOy3VK0L1l0UcMho1YEqLTciJS2rdbjHigYS9DA pnRvjs+8mK3VQGEj7UYQFwt9+/+C07kh9Fo9TWXymmnn/44Us6KqCrzuHS07qrAdAqZY MtjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:content-type:x-original-sender:reply-to :precedence:mailing-list:list-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=ai9s7VXcdayxpYO3zEyd5SR8wnNiLNGS9HyWEVIKRUw=; b=aGUYSQAlqKAFRXx/7qHiEvQOqDyJQgabyofo6EPzc2mziweO9RUSo60EOb6qUuaE/g ApAqDjg1mrcsdmOWJ18FhILwYrets//34TKt3TrFi8Bdk0mJZpi9IPJaKYMVX7PBGKun tUltQbae85l7xo0/rJXcPe6VvN0eeiUSo/mv+p6EbD+Z4EJcI9meqaq/N6fcQGzni0r0 UNFXcmjQ+Iu5afVSmJ0RRRsdHDLV0R1GtLdrm3f+jVHkSsyqws7pRcLen7zVOQ3pe80o 8dQj6n9pzA0QqwIyhOgfb0r2o4wRddk5bY6sD/+d7+1hnxjyMG//8gEqaL3dNsJaDjdx W3zw== X-Gm-Message-State: ALoCoQlWYv81o7UYjhE7hwC5K5Sz6JqaqKzOa6DkO/2Ne5stsuIqSxZI5POGQWwdvDgYAYdTk7gm X-Received: by 10.182.55.105 with SMTP id r9mr824648obp.3.1432178323622; Wed, 20 May 2015 20:18:43 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.140.30.119 with SMTP id c110ls1207455qgc.91.gmail; Wed, 20 May 2015 20:18:42 -0700 (PDT) X-Received: by 10.140.98.138 with SMTP id o10mr4774qge.33.1432178322902; Wed, 20 May 2015 20:18:42 -0700 (PDT) In-Reply-To: <555CDDEF.8000002@gmx.net> X-Original-Sender: fmatthew5876@gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: 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:18092 Archived-At: ------=_Part_4836_1788312111.1432178322075 Content-Type: multipart/alternative; boundary="----=_Part_4837_1268253146.1432178322075" ------=_Part_4837_1268253146.1432178322075 Content-Type: text/plain; charset=UTF-8 On Wednesday, May 20, 2015 at 3:18:24 PM UTC-4, Jens Maurer wrote: > > My suggestion: > > const char * ret = parse(T& v, const char * first, const char * last, int > base, error_code&); > What is the value add of using char* pairs and a char* return vs string_view? Symmetry with iterator algorithms? string_view parse(T& v, string_view s, int base, error_code&); //If you have char* pointers char* cb; char* ce; error_code ec; int value; auto tail = parse(value, {cb,ce}, 10, ec); > > [ret, last[ is the unparsed part of the string. If ret == first, v is not > overwritten and we have an error, otherwise v contains the parsed value. > (Feel free to switch the base vs. error_code& parameters to allow a > defaulted base.) > > You could also add an overload: template inline const char* parse(T& v, const char* b, const char* e, error-code& ec) { return parse(v,b,e,10,ec); } > > This allows some symmetry with similar output operations: > > char * p = output(char * first, char * last, T v); > which outputs "v" into the space provided by [first, last[, > returning the remaining space as [p, last[. > > (This doesn't work with string_view, because it's read-only.) > This kind of API looks like it could be another use case for mstring_view. array_view would also work. -- --- 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. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/. ------=_Part_4837_1268253146.1432178322075 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Wednesday, May 20, 2015 at 3:18:24 PM UTC-4, Je= ns Maurer wrote:
My suggestion:

const char * ret =3D parse(T& v, const char * first, const char * l= ast, int base, error_code&);

What is the value add of using char* p= airs and a char* return vs string_view? Symmetry with iterator algorithms?<= /div>

string_view parse(T& v, string_view s, int = base, error_code&);

//If you have char* pointers=
char* cb;
char* ce;
err= or_code ec= ;
int value;
auto tail =3D parse(value,= {cb,ce}, 10, ec);

 
<= blockquote class=3D"gmail_quote" style=3D"margin: 0;margin-left: 0.8ex;bord= er-left: 1px #ccc solid;padding-left: 1ex;">
[ret, last[ is the unparsed part of the string.  If ret =3D=3D fir= st, v is not
overwritten and we have an error, otherwise v contains the parsed value= ..
(Feel free to switch the base vs. error_code& parameters to allow a= defaulted base.)


You could also add an overload:
<= div>
template <typename T> inline cons= t <= span style=3D"color: #008;" class=3D"styled-by-prettify">char* parse(T& v, const char* b, const char* e,<= /span> error-code& ec) { r= eturn pars= e(<= span style=3D"color: #000;" class=3D"styled-by-prettify">v,b,e,10,ec); }
 

This allows some symmetry with similar output operations:

char * p =3D output(char * first, char * last, T v);  

which outputs "v" into the space provided by [first, last[,
returning the remaining space as [p, last[.

(This doesn't work with string_view, because it's read-only.)

This kind of API looks like it could b= e another use case for mstring_view. array_view<char> would also work= ..

--

---
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.
Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/<= /a>.
------=_Part_4837_1268253146.1432178322075-- ------=_Part_4836_1788312111.1432178322075-- .