From 1f4cde420a19e5bef9160c08b95e1723d4895d01 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Tue, 23 Jul 2024 20:32:39 -0700
Subject: make-like: use seq_build.

* lib.c (make_like): Simplify implementation using seq_build,
which also lets it handle more cases.

* tests/012/seq.tl: New tests. Some existing test fixed,
including one for tuples*.

* txr.1: Documentation updated: mainly that make-like
doesn't strictly require a list argument.
---
 lib.c | 59 +++++++++++++++++++----------------------------------------
 1 file changed, 19 insertions(+), 40 deletions(-)

(limited to 'lib.c')

diff --git a/lib.c b/lib.c
index ed7f0b90..193f8196 100644
--- a/lib.c
+++ b/lib.c
@@ -2419,46 +2419,25 @@ val copy_list(val list)
 
 val make_like(val list, val thatobj)
 {
-  if (list != thatobj) {
-    switch (type(thatobj)) {
-    case VEC:
-      return vec_list(list);
-    case STR:
-    case LIT:
-    case LSTR:
-      if (!opt_compat || opt_compat > 101) {
-        if (!list)
-          return null_string;
-      }
-      if (is_chr(car(list)))
-        return cat_str(list, nil);
-      break;
-    case BUF:
-      if (!list)
-        return make_buf(zero, zero, zero);
-      if (integerp(car(list)))
-        return buf_list(list);
-      break;
-    case COBJ:
-      if (thatobj->co.cls == seq_iter_cls)
-      {
-        struct seq_iter *si = coerce(struct seq_iter *, thatobj->co.handle);
-        return make_like(list, si->inf.obj);
-      }
-      if (obj_struct_p(thatobj)) {
-        val from_list_meth = get_special_slot(thatobj, from_list_m);
-        if (from_list_meth)
-          return funcall1(from_list_meth, list);
-      }
-      if (thatobj->co.cls == carray_cls)
-        return carray_list(list, carray_type(thatobj), nil);
-      break;
-    case NIL:
-    case CONS:
-    case LCONS:
-    default:
-      break;
-    }
+  val self = lit("make-like");
+  type_t tli = type(list);
+  type_t tbj = type(thatobj);
+
+  if (tli != tbj &&
+      !(tli == NIL && tbj == CONS) &&
+      !(tli == CONS && tbj == NIL))
+  {
+    seq_iter_t it;
+    seq_build_t bu;
+    val elem;
+
+    seq_build_init(self, &bu, thatobj);
+    seq_iter_init(self, &it, list);
+
+    while (seq_get(&it, &elem))
+      seq_add(&bu, elem);
+
+    return seq_finish(&bu);
   }
 
   return list;
-- 
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