Move -> and ->> after resolve and add the ability to switch between -…

…> and ->>. Need #262

src/clj/clojure/core.clj

@@ -1121,37 +1121,6 @@
   ([x form] `(. ~x ~form))
   ([x form & more] `(.. (. ~x ~form) ~@more)))
 
-(defmacro defthread-macro 
-  [name docstring args & body]
-  (if (vector? docstring)
-    `(defthread-macro ~name nil ~docstring ~args ~@body)
-    (let [x (first args)
-          form (second args)]
-      `(defmacro ~name
-         ~@(when docstring [docstring]) 
-         {:arglists '([~x] [~x ~form] [~x ~form & ~'more])} 
-         ([x#] x#)
-         ([x# form#] 
-           (let [form# (if (seq? form#) form# (list form#))
-                 ~x x#
-                 ~form form#]
-             (with-meta (do ~@body) (meta form#))))
-         ([x# form# & more#] `(~'~name (~'~name ~x# ~form#) ~@more#))))))
-
-(defthread-macro ->
-  "Threads the expr through the forms. Inserts x as the
-  second item in the first form, making a list of it if it is not a
-  list already. If there are more forms, inserts the first form as the
-  second item in second form, etc."
-  [x form] (list* (first form) x (rest form)))
-
-(defthread-macro ->>
-  "Threads the expr through the forms. Inserts x as the
-  last item in the first form, making a list of it if it is not a
-  list already. If there are more forms, inserts the first form as the
-  last item in second form, etc."
-  [x form] (concat form [x]))
-
 ;;multimethods
 (def global-hierarchy)
 
@@ -2753,8 +2722,8 @@
   "Sequentially read and evaluate the set of forms contained in the
   string"
   [s]
-  (let [rdr (-> (java.io.StringReader. s)
-                (clojure.lang.LineNumberingPushbackReader.))]
+  (let [rdr (clojure.lang.LineNumberingPushbackReader. 
+              (java.io.StringReader. s))]
     (load-reader rdr)))
 
 (defn set
@@ -2958,6 +2927,41 @@
   ([sym] (ns-resolve *ns* sym))
   ([env sym] (ns-resolve *ns* env sym)))
 
+(defmacro defthread-macro 
+  [name docstring args & body]
+  (if (vector? docstring)
+    `(defthread-macro ~name nil ~docstring ~args ~@body)
+    (let [x (first args)
+          form (second args)]
+      `(defmacro ~name
+         ~@(when docstring [docstring]) 
+         {:arglists '([~x] [~x ~form] [~x ~form & ~'more])
+          :thread-op true} 
+         ([x#] x#)
+         ([x# form#] 
+           (let [form# (if (seq? form#) form# (list form#))
+                 ~x x#
+                 ~form form#]
+             (with-meta (do ~@body) (meta form#))))
+         ([x# form# & more#] 
+           (if (and (symbol? form#) (:thread-op (meta (resolve ~'&env form#))))
+             `(~form# ~x# ~@more#)
+             `(~'~name (~'~name ~x# ~form#) ~@more#)))))))
+
+(defthread-macro ->
+  "Threads the expr through the forms. Inserts x as the
+  second item in the first form, making a list of it if it is not a
+  list already. If there are more forms, inserts the first form as the
+  second item in second form, etc."
+  [x form] (list* (first form) x (rest form)))
+
+(defthread-macro ->>
+  "Threads the expr through the forms. Inserts x as the
+  last item in the first form, making a list of it if it is not a
+  list already. If there are more forms, inserts the first form as the
+  last item in second form, etc."
+  [x form] (concat form [x]))
+
 (defn array-map
   "Constructs an array-map."
   ([] (. clojure.lang.PersistentArrayMap EMPTY))