[R] Using the pipe, |>, syntax with "names<-"

[Bert Gunter]

Iris's reply is what I was looking for.  Many thanks -- I can now sleep tonight!

Both Rui's and Duncan's responses merely hid what I wanted to avoid. I
hope that I did not occupy much of your times on my useless question
and rather pathetic attempts at an answer.

Cheers,
Bert



On Sat, Jul 20, 2024 at 3:02 PM Iris Simmons <ikwsimmo using gmail.com> wrote:
>
> It should be written more like this:
>
> ```R
> z <- data.frame(a = 1:3, b = letters[1:3])
> z |> names() |> _[2] <- "foo"
> z
> ```
>
> Regards,
>     Iris
>
> On Sat, Jul 20, 2024 at 4:47 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:
> >
> > With further fooling around, I realized that explicitly assigning my
> > last "solution" 'works'; i.e.
> >
> > names(z)[2] <- "foo"
> >
> > can be piped as:
> >
> >  z <- z |>(\(x) "names<-"(x,value = "[<-"(names(x),2,'foo')))()
> > > z
> >   a foo
> > 1 1   a
> > 2 2   b
> > 3 3   c
> >
> > This is even awfuller than before. So my query still stands.
> >
> > -- Bert
> >
> > On Sat, Jul 20, 2024 at 1:14 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:
> > >
> > > Nope, I still got it wrong: None of my approaches work.  :(
> > >
> > > So my query remains: how to do it via piping with |> ?
> > >
> > > Bert
> > >
> > >
> > > On Sat, Jul 20, 2024 at 1:06 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:
> > > >
> > > > This post is likely pretty useless;  it is motivated by a recent post
> > > > from "Val" that was elegantly answered using Tidyverse constructs, but
> > > > I wondered how to do it using base R only. Along the way, I ran into
> > > > the following question to which I think my answer (below) is pretty
> > > > awful. I would be interested in more elegant base R approaches. So...
> > > >
> > > > z <- data.frame(a = 1:3, b = letters[1:3])
> > > > > z
> > > >   a h
> > > > 1 1 a
> > > > 2 2 b
> > > > 3 3 c
> > > >
> > > > Suppose I want to change the name of the second column of z from 'b'
> > > > to 'foo' . This is very easy using nested function syntax by:
> > > >
> > > > names(z)[2] <- "foo"
> > > > > z
> > > >   a foo
> > > > 1 1   a
> > > > 2 2   b
> > > > 3 3   c
> > > >
> > > > Now suppose I wanted to do this using |> syntax, along the lines of:
> > > >
> > > > z |> names()[2] <- "foo"  ## throws an error
> > > >
> > > > Slightly fancier is:
> > > >
> > > > z |> (\(x)names(x)[2] <- "b")()
> > > > ## does nothing, but does not throw an error.
> > > >
> > > > However, the following, which resulted from a more careful read of
> > > > ?names works (after changing the name of the second column back to "b"
> > > > of course):
> > > >
> > > > z |>(\(x) "names<-"(x,value = "[<-"(names(x),2,'foo')))()
> > > > >z
> > > >   a foo
> > > > 1 1   a
> > > > 2 2   b
> > > > 3 3   c
> > > >
> > > > This qualifies to me as "pretty awful." I'm sure there are better ways
> > > > to do this using pipe syntax, so I would appreciate any better
> > > > approaches.
> > > >
> > > > Best,
> > > > Bert
> >
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