new functions: find-symbol and find-symbol-fb.

Turns out, there is already a find_symbol in lib.c, completely
unused.

* eval.c (eval_init): Register find-symbol and find-symbol-fb
intrinsics.

* lib.c (find_symbol): Fix this hitherto unused function to do
correct defaulting of the package argument and, to accept an
additional argument specifying the not-found value.
(find_symbol_fb): New function.

* lib.c (find_symbol): Declaration updated.
(find_symbol_fb): Declared.

* txr.1: Documented.

1 files changed, 2 insertions, 0 deletions

diff --git a/eval.c b/eval.c
index af3bea23..1e9a5d76 100644
--- a/eval.c
+++ b/eval.c
@@ -6627,6 +6627,8 @@ void eval_init(void)
   reg_fun(intern(lit("unuse-package"), user_package), func_n2o(unuse_package, 1));
   reg_fun(intern(lit("intern"), user_package), func_n2o(intern, 1));
   reg_fun(intern(lit("unintern"), user_package), func_n2o(unintern, 1));
+  reg_fun(intern(lit("find-symbol"), user_package), func_n3o(find_symbol, 1));
+  reg_fun(intern(lit("find-symbol-fb"), user_package), func_n3o(find_symbol_fb, 1));
   reg_fun(intern(lit("rehome-sym"), user_package), func_n2o(rehome_sym, 1));
   reg_fun(intern(lit("package-fallback-list"), user_package), func_n1(package_fallback_list));
   reg_fun(intern(lit("set-package-fallback-list"), user_package), func_n2(set_package_fallback_list));