diff/isec: reset hash/tree iter instead making new.

* lib.c (seq_iter_rewind): Use hash_reset and tree_reset
to rewind the existing iterator rather than allocating a new
one.

* tests/010/hash.tl: New file, covering uni, diff and isec for
hash tables.

* tests/010/tree.tl: New tests.

3 files changed, 13 insertions, 2 deletions

diff --git a/lib.c b/lib.c
index 6145c4f3..5419494e 100644
--- a/lib.c
+++ b/lib.c
@@ -740,10 +740,10 @@ static void seq_iter_rewind(seq_iter_t *it, val self)
       it->ui.index = 0;
       break;
     case SEQ_HASHLIKE:
-      it->ui.iter = hash_begin(it->inf.obj);
+      it->ui.iter = hash_reset(it->ui.iter, it->inf.obj);
       break;
     case SEQ_TREELIKE:
-      it->ui.iter = tree_begin(it->inf.obj);
+      it->ui.iter = tree_reset(it->ui.iter, it->inf.obj);
       break;
     default:
       break;
diff --git a/tests/010/hash.tl b/tests/010/hash.tl
new file mode 100644
index 00000000..b8c386e2
--- /dev/null
+++ b/tests/010/hash.tl
@@ -0,0 +1,6 @@
+(load "../common")
+
+(mtest
+  (uni #H(() ("a") ("b")) #H(() ("b") ("c"))) (("a") ("b") ("c"))
+  (diff #H(() ("a") ("b")) #H(() ("b") ("c"))) (("a"))
+  (isec #H(() ("a") ("b")) #H(() ("b") ("c"))) (("b")))
diff --git a/tests/010/tree.tl b/tests/010/tree.tl
index 86a21167..c2fe5382 100644
--- a/tests/010/tree.tl
+++ b/tests/010/tree.tl
@@ -127,3 +127,8 @@
     tr #T((identity < =) 1 2 3)
     (copy-search-tree tr) #T((identity < =) 1 2 3)
     (make-similar-tree tr) #T((identity < =))))
+
+(mtest
+  (uni #T(() "a" "b") #T(() "b" "c")) ("a" "b" "c")
+  (diff #T(() "a" "b") #T(() "b" "c")) ("a")
+  (isec #T(() "a" "b") #T(() "b" "c")) ("b"))