iuke-tier@ey m@iii@g oii uiow@@edu
2022-Apr-21 15:57 UTC
[Rd] [External] Re: Pipe operator status, placeholders?
At some point there will probably be a blog post about the design of the forward pipe operator in base, but that is not something I will think about until after the current semester is over and my backlog of other things is cleared. Best, luke On Tue, 19 Apr 2022, peter dalgaard wrote:> You probably want Luke Tierney for the full story, but what I gather from the deliberations (on the private R-core list), there are issues with how non-funcall syntax like lm(....) |> _$coef[2] should work. This, in turn, has to do with wanting to have the placeholder occur only as a toplevel substitution (i.e. "["("$"(_, coef), 2) is a no-go. And the reason for that has to do with the way the pipe works in the absense of placeholder, e.g. the parser gets confused by > >> x |> f(g(x=_)) > Error in f(x, g(x = "_")) : invalid use of pipe placeholder > > -pd > >> On 17 Apr 2022, at 01:04 , Benjamin Redelings <benjamin.redelings at gmail.com> wrote: >> >> Hi, >> >> I see that R 4.2 adds the underscore _ as a placeholder for the new forward pipe operator |> , but only for named arguments. The reason why placeholders for position arguments was NOT added isn't clear to me, so I've been looking for the discussion around the introduction of the placeholder. >> >> By searching subject lines in the r-devel mailing list archive, I've found >> >> https://stat.ethz.ch/pipermail/r-devel/2021-April/080646.html >> >> https://stat.ethz.ch/pipermail/r-devel/2021-January/080396.html >> >> https://stat.ethz.ch/pipermail/r-devel/2020-December/080173.html and following messages >> >> but not much else. >> >> 1. Am I looking in the wrong place? >> >> 2. What is the reasoning behind allowing _ as a placeholder only for named arguments? >> >> take care, >> >> -BenRI >> >> ______________________________________________ >> R-devel at r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel > >-- Luke Tierney Ralph E. Wareham Professor of Mathematical Sciences University of Iowa Phone: 319-335-3386 Department of Statistics and Fax: 319-335-3017 Actuarial Science 241 Schaeffer Hall email: luke-tierney at uiowa.edu Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
Benjamin Redelings
2022-Apr-23 15:01 UTC
[Rd] [External] Re: Pipe operator status, placeholders?
Completely understandable.? I'll look forward to hearing more about it later. -BenRI On 4/21/22 11:57 AM, luke-tierney at uiowa.edu wrote:> At some point there will probably be a blog post about the design of > the forward pipe operator in base, but that is not something I will > think about until after the current semester is over and my backlog of > other things is cleared. > > Best, > > luke > > On Tue, 19 Apr 2022, peter dalgaard wrote: > >> You probably want Luke Tierney for the full story, but what I gather >> from the deliberations (on the private R-core list), there are issues >> with how non-funcall syntax like lm(....) |> _$coef[2] should work. >> This, in turn, has to do with wanting to have the placeholder occur >> only as a toplevel substitution (i.e. "["("$"(_, coef), 2) is a >> no-go. And the reason for that has to do with the way the pipe works >> in the absense of placeholder, e.g. the parser gets confused by >> >>> x |> f(g(x=_)) >> Error in f(x, g(x = "_")) : invalid use of pipe placeholder >> >> -pd >> >>> On 17 Apr 2022, at 01:04 , Benjamin Redelings >>> <benjamin.redelings at gmail.com> wrote: >>> >>> Hi, >>> >>> I see that R 4.2 adds the underscore _ as a placeholder for the new >>> forward pipe operator |> , but only for named arguments. The reason >>> why placeholders for position arguments was NOT added isn't clear to >>> me, so I've been looking for the discussion around the introduction >>> of the placeholder. >>> >>> By searching subject lines in the r-devel mailing list archive, I've >>> found >>> >>> https://stat.ethz.ch/pipermail/r-devel/2021-April/080646.html >>> >>> https://stat.ethz.ch/pipermail/r-devel/2021-January/080396.html >>> >>> https://stat.ethz.ch/pipermail/r-devel/2020-December/080173.html and >>> following messages >>> >>> but not much else. >>> >>> 1. Am I looking in the wrong place? >>> >>> 2. What is the reasoning behind allowing _ as a placeholder only for >>> named arguments? >>> >>> take care, >>> >>> -BenRI >>> >>> ______________________________________________ >>> R-devel at r-project.org mailing list >>> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> >
Benjamin Redelings
2022-Sep-01 12:12 UTC
[Rd] [External] Re: Pipe operator status, placeholders?
Hi, Did you manage to get to a blog post at some point? I just saw that there was an live-streaming lecture on August 4th - https://sms.wgtn.ac.nz/cgi-bin/seminars?rm=details&id=987 Was this perhaps recorded anywhere? -BenRI On 4/21/22 11:57 AM, luke-tierney at uiowa.edu wrote:> At some point there will probably be a blog post about the design of > the forward pipe operator in base, but that is not something I will > think about until after the current semester is over and my backlog of > other things is cleared. > > Best, > > luke > > On Tue, 19 Apr 2022, peter dalgaard wrote: > >> You probably want Luke Tierney for the full story, but what I gather >> from the deliberations (on the private R-core list), there are issues >> with how non-funcall syntax like lm(....) |> _$coef[2] should work. >> This, in turn, has to do with wanting to have the placeholder occur >> only as a toplevel substitution (i.e. "["("$"(_, coef), 2) is a >> no-go. And the reason for that has to do with the way the pipe works >> in the absense of placeholder, e.g. the parser gets confused by >> >>> x |> f(g(x=_)) >> Error in f(x, g(x = "_")) : invalid use of pipe placeholder >> >> -pd >> >>> On 17 Apr 2022, at 01:04 , Benjamin Redelings >>> <benjamin.redelings at gmail.com> wrote: >>> >>> Hi, >>> >>> I see that R 4.2 adds the underscore _ as a placeholder for the new >>> forward pipe operator |> , but only for named arguments. The reason >>> why placeholders for position arguments was NOT added isn't clear to >>> me, so I've been looking for the discussion around the introduction >>> of the placeholder. >>> >>> By searching subject lines in the r-devel mailing list archive, I've >>> found >>> >>> https://stat.ethz.ch/pipermail/r-devel/2021-April/080646.html >>> >>> https://stat.ethz.ch/pipermail/r-devel/2021-January/080396.html >>> >>> https://stat.ethz.ch/pipermail/r-devel/2020-December/080173.html and >>> following messages >>> >>> but not much else. >>> >>> 1. Am I looking in the wrong place? >>> >>> 2. What is the reasoning behind allowing _ as a placeholder only for >>> named arguments? >>> >>> take care, >>> >>> -BenRI >>> >>> ______________________________________________ >>> R-devel at r-project.org mailing list >>> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> >