New function: macroexpand-params.

* stdlib/pmac.tl (macroexpand-params): New function,
implemented using newly exposed sys:expand-param-macro.

* autoload.c (pmac_set_entries): Trigger pmac.tl autload
on macroexpand-params symbol.

* eval.c (eval_init): Register existing expand_param_macro
function as sys:expand-param-macro.

* txr.1: Documented.

* stdlib/doc-syms.tl: Updated.

5 files changed, 76 insertions, 1 deletions

diff --git a/autoload.c b/autoload.c
index c8db544b..a3430a63 100644
--- a/autoload.c
+++ b/autoload.c
@@ -504,7 +504,7 @@ static val tagbody_instantiate(void)
 static val pmac_set_entries(val fun)
 {
   val name[] = {
-    lit("define-param-expander"), nil
+    lit("define-param-expander"), lit("macroexpand-params"), nil
   };
   autoload_set(al_fun, name, fun);
   return nil;
diff --git a/eval.c b/eval.c
index acf3b2e2..8d7ea7e4 100644
--- a/eval.c
+++ b/eval.c
@@ -7107,6 +7107,7 @@ void eval_init(void)
   reg_fun(intern(lit("macroexpand-lisp1"), user_package),
           func_n2o(macroexpand_lisp1, 1));
   reg_fun(intern(lit("expand-params"), system_package), func_n5(expand_params));
+  reg_fun(intern(lit("expand-param-macro"), system_package), func_n4(expand_param_macro));
   reg_fun(intern(lit("constantp"), user_package), func_n2o(constantp, 1));
   reg_fun(intern(lit("make-env"), user_package), func_n3o(make_env_intrinsic, 0));
   reg_fun(intern(lit("env-fbind"), user_package), func_n3(env_fbind));
diff --git a/stdlib/doc-syms.tl b/stdlib/doc-syms.tl
index 5cc46e6b..d6c001c1 100644
--- a/stdlib/doc-syms.tl
+++ b/stdlib/doc-syms.tl
@@ -1186,6 +1186,7 @@
       ("macroexpand-1" "N-02ED5471")
       ("macroexpand-1-lisp1" "N-01E62179")
       ("macroexpand-lisp1" "N-01E62179")
+      ("macroexpand-params" "N-037EB49A")
       ("macrolet" "N-00AC12C0")
       ("madv-dontneed" "N-027D1E84")
       ("madv-normal" "N-027D1E84")
diff --git a/stdlib/pmac.tl b/stdlib/pmac.tl
index e530fddc..b78426ba 100644
--- a/stdlib/pmac.tl
+++ b/stdlib/pmac.tl
@@ -33,3 +33,10 @@
           (lambda (,parms ,body ,env ,form)
             ,*forms))
      ,keyword))
+
+(defun macroexpand-params (prototype-form : env)
+  (tree-case prototype-form
+    ((name params . body)
+       (cons name (sys:expand-param-macro params body env prototype-form)))
+    (else (error "~s: invalid prototype-form argument ~s"
+                 %fun% prototype-form))))
diff --git a/txr.1 b/txr.1
index 2cdbd06a..5d2f076f 100644
--- a/txr.1
+++ b/txr.1
@@ -41675,6 +41675,72 @@ Boolean indicator params:
   (keyfun) -> (10 nil 20 nil)
 .brev
 
+.coNP Function @ macroexpand-params
+.synb
+.mets (expand-params < proto-form <> [ env ])
+.syne
+.desc
+The
+.code expand-param
+function expands all of the parameter list macros expressed in the
+.I "prototype form"
+.metn proto-form ,
+returning an expanded version of the form.
+
+The
+.meta proto-form
+is a compound for which has a shape very similar to a lambda
+expression, and may be a lambda expression.
+
+The first element of
+.meta proto-form
+is a name, which is an arbitrary object, though the use of a symbol
+is strongly recommended. This object plays no role in
+.code expand-params
+other than for composing diagnostic messages if errors occur.
+
+The second element of
+.meta proto-form
+is the parameter list.
+
+The remaining elements of
+.meta proto-form
+are zero or more body forms.
+
+If
+.meta proto-form
+contains no parameter macro invocations, then it is returned.
+
+The optional
+.meta env
+parmeter specifies the macro environment which is passed to the
+parameter macro expanders, which they can receive via the
+.code :env
+parameter. The default value
+.code nil
+sepcifies the top-level environment.
+
+.TP* Examples:
+
+.verb
+;; No expansion: argument is returned
+(macroexpand-params '(foo (arg) body)) -> (foo (arg) body)
+
+;; Expand :key macro
+(macroexpand-params '(bar (:key a b c -- d (e 1234 f-p)) body))
+--> (bar (a b c . #:g0014)
+      (let (d e f-p)
+        (let ((#:g0015 (memp :d #:g0014)))
+          (when #:g0015
+            (set d (cadr #:g0015))))
+        (let ((#:g0015 (memp :e #:g0014)))
+          (cond 
+            (#:g0015 (set e (cadr #:g0015))
+                     (set f-p t))
+            (t (set e 1234))))
+        body))
+.brev
+
 .SS* Mutation of Syntactic Places
 .coNP Macro @ set
 .synb