| list_insert {listr} | R Documentation |
Insert an element into a list.
Description
Insert an element into a list.
Usage
list_insert(in_list, item, index, name = NULL, pad = FALSE)
list_append(in_list, item, name = NULL)
list_prepend(in_list, item, name = NULL)
Arguments
in_list |
The list to work on. |
item |
The item to add to the list. |
index |
The index to insert at. |
name |
Optional name for the new item. |
pad |
Add 'NULL' elements for too large indices? |
Details
The 'index' behaves in the way that everything including the specified index will be moved one position forward. Thus, if you insert at index 2, the old item at index 2 will be moved to index 3. If 'index' is larger than the length of 'in_list' the default behaviour is to just add the new item to the end of the list, however if you specify 'pad = TRUE' then as many 'NULL' elements as needed are added to the list to insert 'item' at the specified location.
The functions 'list_append' and 'list_prepend' exist as a simple short-cut for appending and prepending to a list.
Value
A list, the same as 'in_list' but with 'item' added at 'index'.
Examples
my_list <- list(foo1 = 1:10, foo2 = LETTERS[1:10])
list_insert(my_list, rnorm(3), 2, name = "bar")