symdiff: new function.

* eval.c (eval_init): Register symdiff intrinsic.

* lib.c (symdiff): New function.

* lib.h (us_car_p, us_cdr_p): New inline functions.
(symdiff): Declared.

* txr.1: Documented, also fixing issues not related to
symdiff doc.

1 files changed, 1 insertions, 0 deletions

diff --git a/eval.c b/eval.c
index d1013871..7b8c6b35 100644
--- a/eval.c
+++ b/eval.c
@@ -6748,6 +6748,7 @@ void eval_init(void)
   reg_fun(intern(lit("multi-sort"), user_package), func_n3o(multi_sort, 2));
   reg_fun(intern(lit("set-diff"), user_package), func_n4o(set_diff, 2));
   reg_fun(intern(lit("diff"), user_package), func_n4o(diff, 2));
+  reg_fun(intern(lit("symdiff"), user_package), func_n4o(symdiff, 2));
   reg_fun(intern(lit("isec"), user_package), func_n4o(isec, 2));
   reg_fun(intern(lit("uni"), user_package), func_n4o(uni, 2));