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).

2 files changed, 9 insertions, 17 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;
diff --git a/txr.1 b/txr.1
index 83fdfe63..e6a1e1c1 100644
--- a/txr.1
+++ b/txr.1
@@ -56036,9 +56036,8 @@ is also returned.
 The
 .code group-by
 function produces a hash table from
-.metn sequence ,
-which is a
-list or vector. Entries of the hash table are not elements of
+.metn sequence .
+Entries of the hash table are not elements of
 .metn sequence ,
 but lists of elements of
 .metn sequence .
@@ -56088,7 +56087,7 @@ Group the integers from 0 to 10 into three buckets keyed on 0, 1 and 2
 according to the modulo 3 congruence:
 
 .verb
-  (group-by (op mod @1 3) (range 0 10))
+  (group-by (op mod @1 3) 0..11)
   -> #H(() (0 (0 3 6 9)) (1 (1 4 7 10)) (2 (2 5 8)))
 .brev
 
@@ -56096,7 +56095,7 @@ Same as above, but associate the keys with the sums of the
 buckets:
 
 .verb
-  [group-map (op mod @1 3) sum (range 0 10)]
+  [group-map (op mod @1 3) sum 0..11]
   -> #H(() (0 18) (1 22) (2 15))
 .brev