* lib.c (upop): New function.

* lib.h (upop): Declared.

* txr.c (txr_main): Two bugfixes. One is that the argument -
was being pushed back twice resulting in *args* being ("-" "-").
This is because the option processing loop checked for "-" and pushed
it back into args, and then some logic after the loop pushed arg back
into args again. But, these pushes were wrong because they push
back a different cons cell; we would like to be able to
do (ldiff *full-args* *args*). This is solved by upop, which provides
one element of undo. After upop, we can restore the prior list
from the undo save location.

1 files changed, 1 insertions, 0 deletions

diff --git a/lib.h b/lib.h
index ab519088..c1524891 100644
--- a/lib.h
+++ b/lib.h
@@ -385,6 +385,7 @@ val *tail(val cons);
 val *lastcons(val list);
 val *ltail(val *cons);
 val pop(val *plist);
+val upop(val *plist, val *pundo);
 val push(val v, val *plist);
 val copy_list(val list);
 val make_like(val list, val thatobj);