R readr with_edition 暂时更改活动阅读器版本

with_edition(edition, code)

local_edition(edition, env = parent.frame())

with_edition(1, edition_get())
#> [1] 1
with_edition(2, edition_get())
#> [1] 2

# readr 1e and 2e behave differently when input rows have different number
# number of fields
with_edition(1, read_csv("1,2\n3,4,5", col_names = c("X", "Y", "Z")))
#> Warning: 1 parsing failure.
#> row col  expected    actual         file
#>   1  -- 3 columns 2 columns literal data
#> # A tibble: 2 × 3
#>       X     Y     Z
#>   <dbl> <dbl> <dbl>
#> 1     1     2    NA
#> 2     3     4     5
with_edition(2, read_csv("1,2\n3,4,5", col_names = c("X", "Y", "Z")))
#> Warning: One or more parsing issues, call `problems()` on your data frame for
#> details, e.g.:
#>   dat <- vroom(...)
#>   problems(dat)
#> Rows: 2 Columns: 2
#> ── Column specification ──────────────────────────────────────────────────
#> Delimiter: ","
#> dbl (1): X
#> num (1): Y
#> 
#> ℹ Use `spec()` to retrieve the full column specification for this data.
#> ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
#> # A tibble: 2 × 2
#>       X     Y
#>   <dbl> <dbl>
#> 1     1     2
#> 2     3    45

# local_edition() applies in a specific scope, for example, inside a function
read_csv_1e <- function(...) {
  local_edition(1)
  read_csv(...)
}
read_csv("1,2\n3,4,5", col_names = c("X", "Y", "Z"))      # 2e behaviour
#> Warning: One or more parsing issues, call `problems()` on your data frame for
#> details, e.g.:
#>   dat <- vroom(...)
#>   problems(dat)
#> Rows: 2 Columns: 2
#> ── Column specification ──────────────────────────────────────────────────
#> Delimiter: ","
#> dbl (1): X
#> num (1): Y
#> 
#> ℹ Use `spec()` to retrieve the full column specification for this data.
#> ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
#> # A tibble: 2 × 2
#>       X     Y
#>   <dbl> <dbl>
#> 1     1     2
#> 2     3    45
read_csv_1e("1,2\n3,4,5", col_names = c("X", "Y", "Z"))   # 1e behaviour
#> Warning: 1 parsing failure.
#> row col  expected    actual         file
#>   1  -- 3 columns 2 columns literal data
#> # A tibble: 2 × 3
#>       X     Y     Z
#>   <dbl> <dbl> <dbl>
#> 1     1     2    NA
#> 2     3     4     5
read_csv("1,2\n3,4,5", col_names = c("X", "Y", "Z"))      # 2e behaviour
#> Warning: One or more parsing issues, call `problems()` on your data frame for
#> details, e.g.:
#>   dat <- vroom(...)
#>   problems(dat)
#> Rows: 2 Columns: 2
#> ── Column specification ──────────────────────────────────────────────────
#> Delimiter: ","
#> dbl (1): X
#> num (1): Y
#> 
#> ℹ Use `spec()` to retrieve the full column specification for this data.
#> ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
#> # A tibble: 2 × 2
#>       X     Y
#>   <dbl> <dbl>
#> 1     1     2
#> 2     3    45