dynj: add with-bindings

I've written `(with-bindings* m (fn [x] (do-something))` often enough
now to wish for a little more convenience.

Author: kenranunderscore

src/active/clojure/dynj.clj

@@ -39,7 +39,8 @@
   "
   (:refer-clojure :rename {bound-fn* clj-bound-fn*
                            binding clj-binding
-                           with-bindings* clj-with-bindings*}))
+                           with-bindings* clj-with-bindings*
+                           with-bindings clj-with-bindings}))
 
 (defn- dynj-name [dynj]
   #_(symbol (name (ns-name (:ns (meta dynj))))
@@ -105,6 +106,11 @@
   (assert (every? dynj-var? (keys binding-map)))
   (clj-with-bindings* binding-map thunk))
 
+(defmacro with-bindings
+  "Executes `body` using implementations defined via a map of dynj vars."
+  [binding-map & body]
+  `(with-bindings* ~binding-map (fn [] ~@body)))
+
 (defn merge-dynjs
   "Like merge, but asserts that all keys are dynj vars, and the same
   vars are not bound to different implementations."

test/active/clojure/dynj_test.clj

@@ -45,6 +45,13 @@
         ;; expects a thunk
         (fn [] (foo 3))))))
 
+(t/deftest with-bindings-test
+  (t/is
+   (= 11
+      (dynj/with-bindings
+        {#'foo (fn [x] (+ x 4))}
+        (foo 7)))))
+
 (dynj/defn-dynj bar [arg]
   (* 3 arg))
 
@@ -56,9 +63,8 @@
         b2 {#'bar (fn [x] (str x "foo"))}
         bindings (dynj/merge-dynjs b1 b2)]
     (t/is "17foo"
-          (dynj/with-bindings* bindings
-            (fn []
-              (bar (foo 16)))))
+          (dynj/with-bindings bindings
+            (bar (foo 16))))
     (dynj/merge-dynjs b1 b2))
   (t/is
    (thrown? AssertionError