matcher: add :match parameter macro.

With this, we can do matching anywhere we are able to specify
a function parameter list and a body, and we can specify
ordinary arguments, which are inserted to the left of the
implicit match. Plus, it specialy integrates with :key.

* lisplib.c (match_set_entries): Autoload on :match.

* share/txr/stdlib/match.tl (:match): New parameter macro.

* txr.1: Documented.

1 files changed, 6 insertions, 0 deletions

diff --git a/lisplib.c b/lisplib.c
index c0d6ded0..79c7087b 100644
--- a/lisplib.c
+++ b/lisplib.c
@@ -878,6 +878,12 @@ static val match_set_entries(val dlt, val fun)
     lit("lambda-match"), lit("defun-match"),
     nil
   };
+  val match_k = intern(lit("match"), keyword_package);
+
+  if (fun)
+    sethash(dlt, match_k, fun);
+  else
+    remhash(dlt, match_k);
 
   set_dlt_entries(dlt, name, fun);
   intern_only(name_noload);