combi: fix permi and rpermi; impl combi, rcombi; test.

* combi.c (permi_get, permi_peek): Fix algorithm.
(permi_mark): New static function.
(permi_ops): Reference permi_mark for mark operation.
(permi): Initialize it->ul.next to nao as required by
new get/peek algorithm.
(rpermi_get, rpermi_peek): Fix algorithm.
(rpermi_mark): New static function.
(rpermi_ops): Reference permi_mark for mark operation.
(rpermi): Initialize it->ul.next to nao as required
by new get/peek algorithm.
(combi_get, combi_peek, combi_mark, combi_clone): New static
functions.
(combi_ops): New static structure.
(combi): New function.
(rcombi_get, rcombi_peek, rcombi_mark, rcombi_clone): New
static functions.
(rcombi_ops): New static structure.
(rcombi): New function.

* combi.h (combi, rcombi): Declared.

* tests/015/comb.tl: New tests.

1 files changed, 2 insertions, 0 deletions

diff --git a/combi.h b/combi.h
index 17465cc1..b2a78233 100644
--- a/combi.h
+++ b/combi.h
@@ -31,4 +31,6 @@ val permi(val seq, val k);
 val rperm(val seq, val k);
 val rpermi(val seq, val k);
 val comb(val seq, val k);
+val combi(val seq, val k);
 val rcomb(val seq, val k);
+val rcombi(val seq, val k);