group-by: use sequence iteration.

* hash.c (group_by): Replace obsolete list/vector switching
with seq_iter_t iteration. The group-by function is limited
otherwise.

* txr.1: Update group-by documentation not to assert that
the sequence argument is required to be a list or vector.
Examples for group-by and group-map now use a 0..11 range
instead of (range 0 10).

1 files changed, 5 insertions, 12 deletions

diff --git a/hash.c b/hash.c
index 8932a856..cfd4826c 100644
--- a/hash.c
+++ b/hash.c
@@ -1761,20 +1761,13 @@ val group_by(val func, val seq, struct args *hashv_args)
 {
   val self = lit("group-by");
   val hash = hashv(hashv_args);
+  seq_iter_t iter;
+  val elem;
 
-  if (vectorp(seq)) {
-    cnum i, len;
+  seq_iter_init(self, &iter, seq);
 
-    for (i = 0, len = c_fixnum(length(seq), self); i < len; i++) {
-      val v = vecref(seq, num_fast(i));
-      pushhash(hash, funcall1(func, v), v);
-    }
-  } else {
-    for (; seq; seq = cdr(seq)) {
-      val v = car(seq);
-      pushhash(hash, funcall1(func, v), v);
-    }
-  }
+  while (seq_get(&iter, &elem))
+    pushhash(hash, funcall1(func, elem), elem);
 
   {
     struct hash_iter hi;