Flatten recursive list

Question

There are quite a few questions apparently on this topic, but I can\'t see any general solution proposed: I have a deeply recursive list and want to flatten it into a single lis

Answer 1

rlang::squash is pretty magical:

set.seed(47)

d = list(list(list(iris[sample(1:150,3),],
                   iris[sample(1:150,3),]),
              list(list(iris[sample(1:150,3),],
                        list(iris[sample(1:150,3),],
                             iris[sample(1:150,3),])
              ))
))

rlang::squash(d)
#> [[1]]
#>     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
#> 147          6.3         2.5          5.0         1.9  virginica
#> 56           5.7         2.8          4.5         1.3 versicolor
#> 113          6.8         3.0          5.5         2.1  virginica
#> 
#> [[2]]
#>     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
#> 124          6.3         2.7          4.9         1.8  virginica
#> 86           6.0         3.4          4.5         1.6 versicolor
#> 103          7.1         3.0          5.9         2.1  virginica
#> 
#> [[3]]
#>    Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
#> 59          6.6         2.9          4.6         1.3 versicolor
#> 70          5.6         2.5          3.9         1.1 versicolor
#> 81          5.5         2.4          3.8         1.1 versicolor
#> 
#> [[4]]
#>     Sepal.Length Sepal.Width Petal.Length Petal.Width   Species
#> 139          6.0         3.0          4.8         1.8 virginica
#> 21           5.4         3.4          1.7         0.2    setosa
#> 104          6.3         2.9          5.6         1.8 virginica
#> 
#> [[5]]
#>    Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
#> 25          4.8         3.4          1.9         0.2     setosa
#> 90          5.5         2.5          4.0         1.3 versicolor
#> 75          6.4         2.9          4.3         1.3 versicolor