.data does not work properly in case data is stored in a nested column

[psychelzh]

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---

Here my data is nested in one column called dat, then .data cannot detect a column with string, but pick() works as expect.

suppressPackageStartupMessages(library(dplyr))
library(purrr)
test <- tibble::tribble(
  ~target, ~dat,
  "x", data.frame(id = 1:5, x = 1:5)
) 
test |> 
  mutate(
    map2(
      target, dat,
      \(target, dat) {
        dat |> 
          mutate(y = .data[[target]])
      }
    )
  )
#> Error in eval(expr, envir, enclos): 找不到对象'target'
test |> 
  mutate(
    map2(
      target, dat,
      \(target, dat) {
        dat |> 
          mutate(y = pick(all_of(target)))
      }
    )
  )
#> # A tibble: 1 × 3
#>   target dat          `map2(...)` 
#>   <chr>  <list>       <list>      
#> 1 x      <df [5 × 2]> <df [5 × 3]>

^{Created on 2023-09-22 with reprex v2.0.2}

[DavisVaughan]

This is an injecting timing issue, and a known rlang limitation captured by: r-lib/rlang#845

If you wrap the anonymous function up into a separate helper, it avoids the issue

suppressPackageStartupMessages(library(dplyr))
library(purrr)

test <- tibble::tribble(
  ~target, ~dat,
  "x", data.frame(id = 1:5, x = 1:5)
) 

fn <- function(target, dat) {
  dat |> mutate(y = .data[[target]])
}

test |> 
  mutate(
    map2(target, dat, fn)
  )
#> # A tibble: 1 × 3
#>   target dat          `map2(target, dat, fn)`
#>   <chr>  <list>       <list>                 
#> 1 x      <df [5 × 2]> <df [5 × 3]>

^{Created on 2023-11-06 with reprex v2.0.2}