Add chunked seq support to doseq, v2. Refs #1

1 files changed, 43 insertions, 21 deletions

diff --git a/src/clj/clojure/core.clj b/src/clj/clojure/core.clj
index 4096a6ff..f7f4ee99 100644
--- a/src/clj/clojure/core.clj
+++ b/src/clj/clojure/core.clj
@@ -1862,27 +1862,49 @@
                (if-not exprs
                  [true `(do ~@body)]
                  (let [k (first exprs)
-                       v (second exprs)
-                       seqsym (when-not (keyword? k) (gensym))
-                       recform (if (keyword? k) recform `(recur (next ~seqsym)))
-                       steppair (step recform (nnext exprs))
-                       needrec (steppair 0)
-                       subform (steppair 1)]
-                   (cond
-                     (= k :let) [needrec `(let ~v ~subform)]
-                     (= k :while) [false `(when ~v
-                                            ~subform
-                                            ~@(when needrec [recform]))]
-                     (= k :when) [false `(if ~v
-                                           (do
-                                             ~subform
-                                             ~@(when needrec [recform]))
-                                           ~recform)]
-                     :else [true `(loop [~seqsym (seq ~v)]
-                                    (when ~seqsym
-                                      (let [~k (first ~seqsym)]
-                                        ~subform
-                                        ~@(when needrec [recform]))))]))))]
+                       v (second exprs)]
+                   (if (keyword? k)
+                     (let [steppair (step recform (nnext exprs))
+                           needrec (steppair 0)
+                           subform (steppair 1)]
+                       (cond
+                         (= k :let) [needrec `(let ~v ~subform)]
+                         (= k :while) [false `(when ~v
+                                                ~subform
+                                                ~@(when needrec [recform]))]
+                         (= k :when) [false `(if ~v
+                                               (do
+                                                 ~subform
+                                                 ~@(when needrec [recform]))
+                                               ~recform)]))
+                     (let [seq- (gensym "seq_")
+                           chunk- (with-meta (gensym "chunk_")
+                                             {:tag 'clojure.lang.IChunk})
+                           count- (gensym "count_")
+                           i- (gensym "i_")
+                           recform `(recur (next ~seq-) nil (int 0) (int 0))
+                           steppair (step recform (nnext exprs))
+                           needrec (steppair 0)
+                           subform (steppair 1)
+                           recform-chunk 
+                             `(recur ~seq- ~chunk- ~count- (unchecked-inc ~i-))
+                           steppair-chunk (step recform-chunk (nnext exprs))
+                           subform-chunk (steppair-chunk 1)]
+                       [true
+                        `(loop [~seq- (seq ~v), ~chunk- nil,
+                                ~count- (int 0), ~i- (int 0)]
+                           (if (< ~i- ~count-)
+                             (let [~k (.nth ~chunk- ~i-)]
+                               ~subform-chunk
+                               ~@(when needrec [recform-chunk]))
+                             (when ~seq-
+                               (if (chunked-seq? ~seq-)
+                                 (let [c# (chunk-first ~seq-)]
+                                   (recur (seq (chunk-rest ~seq-)) c#
+                                          (int (count c#)) (int 0)))
+                                 (let [~k (first ~seq-)]
+                                   ~subform
+                                   ~@(when needrec [recform]))))))])))))]
     (nth (step nil (seq seq-exprs)) 1)))
 
 (defn dorun