prewalk

Return zipper modified by an isolated depth-first pre-order traversal. Pre-order traversal visits root before children. For example, traversal order of `(1 (2 3 (4 5) 6 (7 8)) 9)` is: 1. `(1 (2 3 (4 5) 6 (7 8)) 9)` 2. `1` 3. `(2 3 (4 5) 6 (7 8))` 4. `2` 5. `3` 6. `(4 5)` 7. `4` 8. `5` 9. `6` 10. `(7 8)` 11. `7` 12. `8` 13. `9` Traversal starts at the current node in `zloc` and continues to the end of the isolated sub-tree. Function `f` is called on the zipper locations satisfying predicate `p?` and must return either - nil to indicate no changes - or a valid zipper WARNING: when function `f` changes the location in the zipper, normal traversal will be affected. When `p?` is not specified `f` is called on all locations. To walk all nodes, you'll want to walk from the root node. You can do this by, for example, using [[of-string*]] instead of [[of-string]]. ```Clojure (-> (zip/of-string* "my clojure forms") (zip/prewalk ...)) ``` See [docs on sub editing](/doc/01-user-guide.adoc#sub-editing).