modifyList for multiple lists

This calls utils::modifyList iteratively using base::Reduce, so it can handle >2 lists. The subsequent list elements that share a name will override previous list elements with that same name. It also will handle the case where any list is a NULL. Note: default keep.null = TRUE, which is different than modifyList

Usage

modifyList2(..., keep.null = FALSE)

modifyList3(..., keep.null = TRUE)

Arguments

...

One or more named lists.

keep.null

If TRUE, NULL elements in val become NULL elements in x. Otherwise, the corresponding element, if present, is deleted from x.

Value

A list: the first argument with each subsequent argument's elements merged in, later ones overriding earlier ones of the same name.

Details

More or less a convenience around Reduce(modifyList, list(...)), with some checks, and the addition of keep.null = TRUE by default.

Note

modifyList3 retains the original behaviour of modifyList2 (prior to Oct 2022); however, it cannot retain NULL values in lists.

Examples

modifyList2(list(a = 1), list(a = 2, b = 2))
#> $a
#> [1] 2
#> 
#> $b
#> [1] 2
#> 
modifyList2(list(a = 1), NULL, list(a = 2, b = 2))
#> $a
#> [1] 2
#> 
#> $b
#> [1] 2
#> 
modifyList2(
  list(a = 1), list(x = NULL), list(a = 2, b = 2),
  list(a = 3, c = list(1:10))
)
#> $a
#> [1] 3
#> 
#> $b
#> [1] 2
#> 
#> $c
#> $c[[1]]
#>  [1]  1  2  3  4  5  6  7  8  9 10
#> 
#>