From 1f7caacd15b24af7fc70ab672d4c65eb09c746cd Mon Sep 17 00:00:00 2001
From: Elliot Glaysher <elliot@tlon.io>
Date: Tue, 12 May 2020 10:40:33 -0700
Subject: [PATCH] jet: +rep:in

---
 pkg/urbit/include/jets/w.h |  1 +
 pkg/urbit/jets/d/in_rep.c  | 41 ++++++++++++++++++++++++++++++++++++++
 pkg/urbit/jets/tree.c      |  2 ++
 3 files changed, 44 insertions(+)
 create mode 100644 pkg/urbit/jets/d/in_rep.c

diff --git a/pkg/urbit/include/jets/w.h b/pkg/urbit/include/jets/w.h
index a0c7aa030c..a3271dc2f8 100644
--- a/pkg/urbit/include/jets/w.h
+++ b/pkg/urbit/include/jets/w.h
@@ -102,6 +102,7 @@
     u3_noun u3wdi_has(u3_noun);
     u3_noun u3wdi_int(u3_noun);
     u3_noun u3wdi_put(u3_noun);
+    u3_noun u3wdi_rep(u3_noun);
     u3_noun u3wdi_run(u3_noun);
     u3_noun u3wdi_tap(u3_noun);
     u3_noun u3wdi_uni(u3_noun);
diff --git a/pkg/urbit/jets/d/in_rep.c b/pkg/urbit/jets/d/in_rep.c
new file mode 100644
index 0000000000..a7d7376c84
--- /dev/null
+++ b/pkg/urbit/jets/d/in_rep.c
@@ -0,0 +1,41 @@
+/* j/4/in_rep.c
+**
+*/
+#include "all.h"
+
+/* internal functions
+ */
+static
+void
+_in_rep(u3_noun a, u3j_site* sit_u, u3_noun* out)
+{
+  if (u3_nul == a) {
+    return;
+  } else {
+    u3_noun n_a, l_a, r_a;
+    u3x_trel(a, &n_a, &l_a, &r_a);
+
+    // consumes out refcount
+    *out = u3j_gate_slam(sit_u, u3nc(u3k(n_a), *out));
+
+    _in_rep(l_a, sit_u, out);
+    _in_rep(r_a, sit_u, out);
+  }
+}
+
+u3_noun
+u3wdi_rep(u3_noun cor)
+{
+  u3_noun a, b;
+  u3j_site sit_u;
+
+  u3x_mean(cor, u3x_sam, &b, u3x_con_sam, &a, 0);
+
+  u3j_gate_prep(&sit_u, u3k(b));
+
+  u3_noun out = u3k(u3x_at(u3x_sam_3, b));
+  _in_rep(a, &sit_u, &out);
+
+  u3j_gate_lose(&sit_u);
+  return out;
+}
diff --git a/pkg/urbit/jets/tree.c b/pkg/urbit/jets/tree.c
index c47073f179..124a39d30c 100644
--- a/pkg/urbit/jets/tree.c
+++ b/pkg/urbit/jets/tree.c
@@ -1574,6 +1574,7 @@ static c3_c* _141_two_xeb_ha[] = {
   };
 
   static u3j_harm _141_two__in_apt_a[] = {{".2", u3wdi_apt}, {}};
+  static u3j_harm _141_two__in_rep_a[] = {{".2", u3wdi_rep}, {}};
   static u3j_harm _141_two__in_run_a[] = {{".2", u3wdi_run}, {}};
 
 static u3j_core _141_two__in_d[] =
@@ -1585,6 +1586,7 @@ static u3j_core _141_two__in_d[] =
     { "has", 7, _141_two__in_has_a, 0, _141_two__in_has_ha },
     // { "int", 7, _141_two__in_int_a, 0, _141_two__in_int_ha },
     { "put", 7, _141_two__in_put_a, 0, _141_two__in_put_ha },
+    { "rep", 7, _141_two__in_rep_a },
     { "run", 7, _141_two__in_run_a },
     { "tap", 7, _141_two__in_tap_a, 0, _141_two__in_tap_ha },
     { "wyt", 3, _141_two__in_wyt_a, 0, _141_two__in_wyt_ha },