Flatten a list of lists into a simple vector

These functions were superseded in purrr 1.0.0 because their behaviour was inconsistent. Superseded functions will not go away, but will only receive critical bug fixes.

• flatten() has been superseded by list_flatten().

• flatten_lgl(), flatten_int(), flatten_dbl(), and flatten_chr() have been superseded by list_c().

• flatten_dfr() and flatten_dfc() have been superseded by list_rbind() and list_cbind() respectively.

Usage

flatten(.x)

flatten_lgl(.x)

flatten_int(.x)

flatten_dbl(.x)

flatten_chr(.x)

flatten_dfr(.x, .id = NULL)

flatten_dfc(.x)

Arguments

.x

A list to flatten. The contents of the list can be anything for flatten() (as a list is returned), but the contents must match the type for the other functions.

Value

flatten() returns a list, flatten_lgl() a logical vector, flatten_int() an integer vector, flatten_dbl() a double vector, and flatten_chr() a character vector.

flatten_dfr() and flatten_dfc() return data frames created by row-binding and column-binding respectively. They require dplyr to be installed.

Examples

x <- map(1:3, \(i) sample(4))
x
#> [[1]]
#> [1] 4 1 3 2
#> 
#> [[2]]
#> [1] 3 4 2 1
#> 
#> [[3]]
#> [1] 2 4 1 3
#> 

# was
x |> flatten_int() |> str()
#>  int [1:12] 4 1 3 2 3 4 2 1 2 4 ...
# now
x |> list_c() |> str()
#>  int [1:12] 4 1 3 2 3 4 2 1 2 4 ...

x <- list(list(1, 2), list(3, 4))
# was
x |> flatten() |> str()
#> List of 4
#>  $ : num 1
#>  $ : num 2
#>  $ : num 3
#>  $ : num 4
# now
x |> list_flatten() |> str()
#> List of 4
#>  $ : num 1
#>  $ : num 2
#>  $ : num 3
#>  $ : num 4