Task #11474

* filter.c (filter_equal): Takes two filters instead of one.
(lfilt_k, rfilt_k): New keyword variables.
(filter_init): New keyword variables initialized.

* filter.h (filter_equal): Declaration updated.
(lfilt_k, rfilt_k): Declared.

* lib.c (funcall4): New function.
(do_curry_1234_34): New static function.
(curry_1234_34): New function.
(do_swap_12_21): New static function.
(swap_12_21): New function.

* lib.h (funcall4, curry_1234_34, swap_12_21): Declared.

* match.c (dest_bind): Swap use the function argument swapping
combinator when calling tree find such that the value
being searched is on the left and pattern material is on the right.
(v_bind): Implemented :lfilt and :rfilt.

* txr.1: Documented :lfilt and :rfilt.

1 files changed, 5 insertions, 3 deletions

diff --git a/filter.c b/filter.c
index 4c787955..3ba2e9a0 100644
--- a/filter.c
+++ b/filter.c
@@ -231,10 +231,10 @@ val filter_string(val filter, val str)
   uw_throwf(error_s, lit("filter_string: invalid filter ~a"), filter, nao);
 }
 
-val filter_equal(val filter, val left, val right)
+val filter_equal(val lfilt, val rfilt, val left, val right)
 {
   if (stringp(left) && stringp(right))
-    return equal(filter_string(filter, left), filter_string(filter, right));
+    return equal(filter_string(lfilt, left), filter_string(rfilt, right));
   return equal(left, right);
 }
 
@@ -565,7 +565,7 @@ static val html_numeric_handler(val ch)
 }
 
 val filters;
-val filter_k, to_html_k, from_html_k;
+val filter_k, lfilt_k, rfilt_k, to_html_k, from_html_k;
 val upcase_k, downcase_k;
 
 void filter_init(void)
@@ -574,6 +574,8 @@ void filter_init(void)
 
   filters = make_hash(nil, nil);
   filter_k = intern(lit("filter"), keyword_package);
+  lfilt_k = intern(lit("lfilt"), keyword_package);
+  rfilt_k = intern(lit("rfilt"), keyword_package);
   to_html_k = intern(lit("to_html"), keyword_package);
   from_html_k = intern(lit("from_html"), keyword_package);
   upcase_k = intern(lit("upcase"), keyword_package);