From 4676550961c10b5aec8761c52154c88153bbd4be Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Tue, 22 Jul 2014 14:08:48 +0900
Subject: [PATCH] rewrite vector-append in c

---
 piclib/prelude.scm | 12 +-----------
 src/vector.c       | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/piclib/prelude.scm b/piclib/prelude.scm
index e2aa17d5..71e5a11a 100644
--- a/piclib/prelude.scm
+++ b/piclib/prelude.scm
@@ -639,23 +639,13 @@
 (define (vector . objs)
   (list->vector objs))
 
-(define (vector-append . vs)
-  (define (vector-append-2-inv w v)
-    (let ((res (make-vector (+ (vector-length v) (vector-length w)))))
-      (vector-copy! res 0 v)
-      (vector-copy! res (vector-length v) w)
-      res))
-  (fold vector-append-2-inv #() vs))
-
 (define (vector->string . args)
   (list->string (apply vector->list args)))
 
 (define (string->vector . args)
   (list->vector (apply string->list args)))
 
-(export vector vector-copy! vector-copy
-        vector-append vector-fill!
-        vector->string string->vector)
+(export vector vector->string string->vector)
 
 ;;; 6.9 bytevector
 
diff --git a/src/vector.c b/src/vector.c
index 8fe9392c..d57214e7 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -173,6 +173,34 @@ pic_vec_vector_copy(pic_state *pic)
   return pic_obj_value(to);
 }
 
+static pic_value
+pic_vec_vector_append(pic_state *pic)
+{
+  size_t argc, i, j, len;
+  pic_value *argv;
+  pic_vec *vec;
+
+  pic_get_args(pic, "*", &argc, &argv);
+
+  len = 0;
+  for (i = 0; i < argc; ++i) {
+    pic_assert_type(pic, argv[i], vec);
+    len += pic_vec_ptr(argv[i])->len;
+  }
+
+  vec = pic_vec_new(pic, len);
+
+  len = 0;
+  for (i = 0; i < argc; ++i) {
+    for (j = 0; j < pic_vec_ptr(argv[i])->len; ++j) {
+      vec->data[len + j] = pic_vec_ptr(argv[i])->data[j];
+    }
+    len += pic_vec_ptr(argv[i])->len;
+  }
+
+  return pic_obj_value(vec);
+}
+
 static pic_value
 pic_vec_vector_fill_i(pic_state *pic)
 {
@@ -248,6 +276,7 @@ pic_init_vector(pic_state *pic)
   pic_defun(pic, "vector-set!", pic_vec_vector_set);
   pic_defun(pic, "vector-copy!", pic_vec_vector_copy_i);
   pic_defun(pic, "vector-copy", pic_vec_vector_copy);
+  pic_defun(pic, "vector-append", pic_vec_vector_append);
   pic_defun(pic, "vector-fill!", pic_vec_vector_fill_i);
   pic_defun(pic, "list->vector", pic_vec_list_to_vector);
   pic_defun(pic, "vector->list", pic_vec_vector_to_list);