luciano/specter
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

add recursive navigation example

Browse source
This commit is contained in:
Nathan Marz 2016-01-11 14:03:03 -05:00
parent 2ad873da11
commit 06f0d6b656
1 changed files with 13 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
README.md
View file

@ -180,6 +180,19 @@ user> (select [ALL AccountPath :funds]
[50 51 1 2]
```
The next example demonstrates recursive navigation. Here's how to double all the even numbers in a tree:
```clojure
(defprotocolpath TreeWalker [])
(extend-protocolpath TreeWalker
Object nil
clojure.lang.PersistentVector [ALL TreeWalker])
(transform [TreeWalker number? even?] #(* 2 %) [:a 1 [2 [[[3]]] :e] [4 5 [6 7]]])
;; => [:a 1 [4 [[[3]]] :e] [8 5 [12 7]]]
```
You can make `select` and `transform` work much faster by precompiling your selectors using the `comp-paths` function. There's about a 3x speed difference between the following two invocations of transform:
```clojure