tree:

reverse(tree)

Reverses the order of keys in the tree.

$ cat letters.yaml
a: The letter A
b: The letter B
c: The letter C
$ ori reverse letters.yaml
c: The letter C
b: The letter B
a: The letter A
g a The letter A ->a a b The letter B ->b b c The letter C ->c c
g c The letter C ->c c b The letter B ->b b a The letter A ->a a
Input tree
With reversed keys

After sorting by date with sort, it can be useful to reverse that order to get things in reverse chronological order.

reverse only affects the keys at the top level of the tree. For a deep version that affects all levels of a tree, use deepReverse