lambda-set method: treat [struct ...] as place.

* eval.c (eval_init): Change registration of dwim-set to only
one required argument, with the rest variadic.

* lib.c (lambda_set_s): New symbol variable.
(dwim_set): Change to variadic function that takes all
arguments other than the object/sequence being operated on as
struct args *. Rewrite to do a test on the object type first,
handling hashes and structs specially.
(obj_init): Initialize lambda_set_s.

* share/txr/stdlib/place.tl (defplace dwim): Rewritten for
more generic syntax. The only argument required is obj-place;
the other arguments are treated as a variable argument list,
all treated uniformly.  This eliminates the special handling
of the default value for hash lookups.

* args.h (args_count): New inline function.

* txr.1: Updated documentation for dwim operator, which neglects
to mention use over objects thanks to the lambda function.
Documented lambda-set.

1 files changed, 5 insertions, 0 deletions

diff --git a/args.h b/args.h
index 68d301b8..5735b828 100644
--- a/args.h
+++ b/args.h
@@ -181,6 +181,11 @@ INLINE void args_clear(struct args *args)
   args->fill = 0;
 }
 
+INLINE cnum args_count(struct args *args)
+{
+  return args->fill + c_num(length_list(args->list));
+}
+
 val args_get_checked(val name, struct args *args, cnum *arg_index);
 struct args *args_copy(struct args *to, struct args *from);
 struct args *args_copy_zap(struct args *to, struct args *from);