New special macro parameter list parameter :form.

* eval.c (form_k): New keyword symbol variable.
(bind_macro_params): Implement form_k.
(eval_init): Initialize form_k.

* txr.1: Documented :form parameter.

2 files changed, 30 insertions, 12 deletions

diff --git a/eval.c b/eval.c
index bff81a48..6fe44e68 100644
--- a/eval.c
+++ b/eval.c
@@ -98,7 +98,7 @@ val fbind_s, lbind_s, flet_s, labels_s;
 val opip_s, oand_s, chain_s, chand_s;
 val sys_load_s, sys_lisp1_value_s;
 
-val special_s, whole_k, symacro_k;
+val special_s, whole_k, form_k, symacro_k;
 
 val last_form_evaled, last_form_expanded;
 
@@ -765,7 +765,7 @@ static val bind_macro_params(val env, val menv, val params, val form,
   while (consp(params)) {
     val param = car(params);
 
-    if (param == whole_k || param == env_k) {
+    if (param == whole_k || param == form_k || param == env_k) {
       val nparam;
       val next = cdr(params);
       if (!next)
@@ -776,7 +776,11 @@ static val bind_macro_params(val env, val menv, val params, val form,
         err_sym = nparam;
         goto nbind;
       }
-      env_vbind_special(new_env, nparam, if3(param == whole_k, whole, menv),
+      env_vbind_special(new_env, nparam,
+                        if3(param == whole_k,
+                            whole,
+                            if3(param == form_k,
+                                ctx_form, menv)),
                         specials, ctx_form);
       params = cdr(next);
       continue;
@@ -4189,6 +4193,7 @@ void eval_init(void)
   symacrolet_s = intern(lit("symacrolet"), user_package);
   with_saved_vars_s = intern(lit("with-saved-vars"), system_package);
   whole_k = intern(lit("whole"), keyword_package);
+  form_k = intern(lit("form"), keyword_package);
   special_s = intern(lit("special"), system_package);
   symacro_k = intern(lit("symacro"), keyword_package);
   prof_s = intern(lit("prof"), user_package);
diff --git a/txr.1 b/txr.1
index b3dd7451..885bdb11 100644
--- a/txr.1
+++ b/txr.1
@@ -22277,24 +22277,30 @@ and
 receive
 .codn nil .
 
-Macro parameter lists also support two special keywords, namely
-.code :env
+Macro parameter lists also supports two special keywords, namely
+.codn :env ,
+.code :whole
 and
-.codn :whole .
+.codn :form .
 
 The parameter list
-.code (:whole x :env y)
+.code (:whole x :env y :form z)
 will bind parameter
 .code x
 to the entire
-macro parameter list, and bind parameter
+macro parameter list, bind parameter
 .code y
-to the macro environment.
+to the macro environment and bind parameter
+.code z
+to the entire macro form (the original compound form used to invoke the
+macro).
+
 The
+.codn :env ,
 .code :whole
 and
-.code :env
-notation can occur anywhere in a macro parameter list, other than
+.code :form
+notations can occur anywhere in a macro parameter list, other than
 to the right of the consing dot.
 
 .TP* "Dialect Note:"
@@ -22324,7 +22330,14 @@ they are the same and behave the same way. Thus
 is treated the same way in macros as in
 .code tree-bind
 and related binding operators: it binds just the arguments
-to the parameter.
+to the parameter. \*(TL has the special parameter
+.code :form
+by means of which macros can access their invoking form.
+This parameter is also supported in
+.code tree-bind
+and binds to the entire
+.code tree-bind
+form.
 
 .coNP Operator @ macro-time
 .synb