seq_build: fix: incompatible items must create list.

In the make_like function, the list is converted to
string or buffer if the first element of the list
is a character, or integer. We need similar logic in
seq_build. We can make it better. When any item is
added which is incompatible, we can convert what we
have so far to a list, change the seq_build type
to list, and keep going.

* lib.c (seq_build_convert_to_list): New static
function.
(seq_build_str_add, seq_build_buf_add): If the item
is incompatible, convert the string or buffer to
a list and pass to seq_build_convert_to_list.
Then call bu->ops->add to add the item, now as a list.
(seq_build_buf_pend): Function removed.
(sb_buf_ops): Use the seq_build_generic_pend function
for the pend operation. This is because we have to
check each item one by one; we cannot use replace_buf.

1 files changed, 30 insertions, 12 deletions

diff --git a/lib.c b/lib.c
index 8d928c66..a0c26ff0 100644
--- a/lib.c
+++ b/lib.c
@@ -1438,9 +1438,16 @@ static void seq_build_vec_add(seq_build_t *bu, val item)
   vec_push(bu->obj, item);
 }
 
+static void seq_build_convert_to_list(seq_build_t *bu, val list);
+
 static void seq_build_str_add(seq_build_t *bu, val item)
 {
-  string_extend(bu->obj, item, nil);
+  if (chrp(item)) {
+    string_extend(bu->obj, item, nil);
+  } else {
+    seq_build_convert_to_list(bu, list_str(bu->obj));
+    bu->ops->add(bu, item);
+  }
 }
 
 static void seq_build_str_finish(seq_build_t *bu)
@@ -1451,17 +1458,14 @@ static void seq_build_str_finish(seq_build_t *bu)
 static void seq_build_buf_add(seq_build_t *bu, val item)
 {
   val buf = bu->obj;
-  val len = length_buf(buf);
-
-  buf_put_uchar(buf, len, item);
-}
 
-static void seq_build_buf_pend(seq_build_t *bu, val seq)
-{
-  val buf = bu->obj;
-  val len = length_buf(buf);
-
-  replace_buf(buf, seq, len, len);
+  if (integerp(item)) {
+    val len = length_buf(buf);
+    buf_put_uchar(buf, len, item);
+  } else {
+    seq_build_convert_to_list(bu, mapcar_listout(identity_f, buf));
+    bu->ops->add(bu, item);
+  }
 }
 
 static void seq_build_buf_finish(seq_build_t *bu)
@@ -1522,7 +1526,7 @@ static struct seq_build_ops
 
 static struct seq_build_ops
   sb_buf_ops = seq_build_ops_init(seq_build_buf_add,
-                                  seq_build_buf_pend,
+                                  seq_build_generic_pend,
                                   seq_build_buf_finish,
                                   seq_build_obj_mark);
 
@@ -1544,6 +1548,20 @@ static struct seq_build_ops
                                    seq_build_list_finish,
                                    seq_build_obj_mark);
 
+static void seq_build_convert_to_list(seq_build_t *bu, val list)
+{
+  if (list) {
+    val tail = lastcons(list);
+    us_rplacd(tail, list);
+    bu->obj = tail;
+  } else {
+    bu->obj = nil;
+  }
+
+  bu->ops = &sb_list_ops;
+}
+
+
 void seq_build_init(val self, seq_build_t *bu, val likeobj)
 {
   bu->self = self;