[Fix #313] pf doesn't understand %&

No tests are added because of a long standing bug in the test framework
where use of `%s` triggers a 'wrong number of args passed to format'
error.

Author: expez

CHANGELOG.md

@@ -12,6 +12,7 @@
 
 ### Bugs fixed
 
+- [#313](https://github.com/clojure-emacs/clj-refactor.el/issues/313) `*data-readers*` teach `pf` about function literals using `%&`.
 - [#320](https://github.com/clojure-emacs/clj-refactor.el/issues/320) `*data-readers*` ignored when searching for macros.
 
 ## 2.2.0

clj-refactor.el

@@ -2611,10 +2611,12 @@ See: https://github.com/clojure-emacs/clj-refactor.el/wiki/cljr-update-project-d
   (cljr--goto-fn-definition)
   (let ((fn-start (point))
         var replacement)
-    (while (re-search-forward "%[1-9]?" (cljr--point-after 'paredit-forward) t)
+    (while (re-search-forward "%[1-9]?&?" (cljr--point-after 'paredit-forward) t)
       (setq var (buffer-substring (point) (cljr--point-after 'paredit-backward)))
       (setq replacement (read-string (format "%s => " var)))
-      (cljr--append-fn-parameter replacement)
+      (cljr--append-fn-parameter (if (string= "%&" var)
+                                     (format "& %s" replacement)
+                                   replacement))
       (goto-char (1+ fn-start))
       (let ((end (cljr--point-after '(paredit-forward-up 2))))
         (while (re-search-forward (format "\\s-%s\\(\\s-\\|\\|\n)\\)" var)