Pass arguments to f in change task through the reader.

This means that you can use non-strings as args in the change task,
but it requires double-quoting when you do want strings.

doc/DEPLOY.md

@@ -231,7 +231,7 @@ You can use the `lein-pprint` plugin to see the default value of `:release-tasks
 ```
 $ lein pprint :release-tasks
 [["vcs" "assert-committed"]
- ["change" "version" "leiningen.release/bump-version" "release"]
+ ["change" "version" "leiningen.release/bump-version" "\"release\""]
  ["vcs" "commit"]
  ["vcs" "tag"]
  ["deploy"]
@@ -247,7 +247,7 @@ want to automatically bump the version in `project.clj`:
 ```clojure
   :release-tasks [["vcs" "assert-committed"]
                   ["change" "version"
-                   "leiningen.release/bump-version" "release"]
+                   "leiningen.release/bump-version" "\"release\""]
                   ["vcs" "commit"]
                   ["vcs" "tag"]
                   ["deploy"]]

leiningen-core/src/leiningen/core/project.clj

@@ -189,7 +189,7 @@
    ;; If these change, be sure to update release docstring and DEPLOY.md
    :release-tasks ^:top-displace [["vcs" "assert-committed"]
                                   ["change" "version"
-                                   "leiningen.release/bump-version" "release"]
+                                   "leiningen.release/bump-version" "\"release\""]
                                   ["vcs" "commit"]
                                   ["vcs" "tag"]
                                   ["deploy"]

src/leiningen/change.clj

@@ -32,8 +32,7 @@
                 (= "set" f) (constantly (first args))
                 (string? f) (or (utils/require-resolve (symbol f))
                                 (fail-argument! (str "Unable to resolve " f)))
-                :else       (fail-argument!
-                             (str "Expected " f " to implement or reference an IFn")))]
+                :else (fail-argument! (str f " is not a function.")))]
     #(apply f % args)))
 
 ;;; Maven convention helpers
@@ -147,12 +146,15 @@
 ;;; Public API
 
 (defn change-string
+  "Programmatic functional access to project.clj-rewriting.
+
+See the `change` task function which handles reading and writing from disk as
+well as turning string args into Clojure data; this function handles the rest."
   [project-str key-or-path f & args]
   (let [f (collapse-fn f args)
         path (normalize-path key-or-path)
         proj (parse-project project-str)]
     (sj/str-pt
-     ;; TODO: support 'magic' keys within nested scope also
      (condp = path
        [:version] (update-version proj f)
        [:name] (update-name proj f)
@@ -173,16 +175,18 @@ as its first argument and the remaining task aruments as the rest.
 
 This will append \"-SNAPSHOT\" to the current version:
 
-    $ lein change version str \"-SNAPSHOT\"
+    $ lein change version str '\"-SNAPSHOT\"'
 
 When called programmatically, you may pass a coll of keywords for the
 first arg or an actual function for the second.
 
-Note that this task reads the project.clj file from disk rather than
-honoring the project map, so profile merging or `update-in` invocations
-will not effect it."
+All the arguments to f are passed through the reader, so double quoting is
+necessory to use strings. Note that this task reads the project.clj file
+from disk rather than honoring the project map, so profile merging or
+`update-in` invocations will not effect it."
   [project key-or-path f & args]
   ;; cannot work with project map, want to preserve formatting, comments, etc
   (let [project-file (io/file (:root project) "project.clj")
-        source (slurp project-file)]
+        source (slurp project-file)
+        args (map read-string args)]
     (spit project-file (apply change-string source key-or-path f args))))

src/leiningen/release.clj

@@ -32,7 +32,7 @@
   a map of the version incremented in the level argument. Add qualifier unless
   releasing non-snapshot."
   [{:keys [major minor patch qualifier]} level]
-  (case level
+  (case (keyword (name level))
     :major {:major (inc major) :minor 0 :patch 0 :qualifier "SNAPSHOT"}
     :minor {:major major :minor (inc minor) :patch 0 :qualifier "SNAPSHOT"}
     :patch {:major major :minor minor :patch (inc patch) :qualifier "SNAPSHOT"}
@@ -57,7 +57,7 @@ The default list of release tasks is as follows:
 
   :release-tasks [[\"vcs\" \"assert-committed\"]
                   [\"change\" \"version\"
-                   \"leiningen.release/bump-version\" \"release\"]
+                   \"leiningen.release/bump-version\" \"\\\"release\\\"\"]
                   [\"vcs\" \"commit\"]
                   [\"vcs\" \"tag\"]
                   [\"deploy\"]
@@ -83,7 +83,7 @@ is a task name and the rest are arguments to that task.
 The release task takes a single argument which should be one of :major,
 :minor, or :patch to indicate which semantic versioning level to bump. If none
 is given, it defaults to :patch."
-  ([project] (release *level*))
+  ([project] (release project (str *level*)))
   ([project level]
      (binding [*level* (read-string level)]
        (doseq [task (:release-tasks project)]