* filter.c (function_filter): New function.

(get_filter): Handle (fun ...) syntax.

* match.c (v_bind): Establish dynamic environment frame around
dest_bind, and stash the bindings there so filters can have access
to the bindings.
(v_output): Likewise, around do_output calls.
(v_fun): New function.
(match_files): Function handling broken out into v_fun.
(match_funcall): New function.

* match.h (match_funcall): Declared.

* unwind.c (uw_push_env): Initialize match_context.
(uw_get_match_context, uw_set_match_context): New functions.

* unwind.h (struct uw_dynamic_env): New member, match_context.
(uw_get_match_context, uw_set_match_context): Declared.

* txr.1: Documented function filters.

1 files changed, 14 insertions, 0 deletions

diff --git a/unwind.c b/unwind.c
index 143b9033..0d8a48e4 100644
--- a/unwind.c
+++ b/unwind.c
@@ -125,6 +125,7 @@ void uw_push_env(uw_frame_t *fr)
   fr->ev.type = UW_ENV;
   fr->ev.up_env = prev_env;
   fr->ev.func_bindings = nil;
+  fr->ev.match_context = nil;
   fr->ev.up = uw_stack;
   uw_stack = fr;
   uw_env_stack = fr;
@@ -152,6 +153,19 @@ val uw_set_func(val sym, val value)
   return value;
 }
 
+val uw_get_match_context(void)
+{
+  uw_frame_t *env = uw_find_env();
+  return env->ev.match_context;
+}
+
+val uw_set_match_context(val context)
+{
+  uw_frame_t *env = uw_find_env();
+  env->ev.match_context = context;
+  return context;
+}
+
 void uw_pop_frame(uw_frame_t *fr)
 {
   assert (fr == uw_stack);