From 38ce666012304aa51808a3063c388527739e03e9 Mon Sep 17 00:00:00 2001
From: Jared Hance <jared.hance@case.edu>
Date: Wed, 2 Jul 2014 11:11:23 -0400
Subject: [PATCH] Add ++murn.

Maybe turn
---
 arvo/hoon.hoon | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arvo/hoon.hoon b/arvo/hoon.hoon
index 2d39a82891..c2715fcbf4 100644
--- a/arvo/hoon.hoon
+++ b/arvo/hoon.hoon
@@ -698,6 +698,15 @@
   ?:  (b i.a)  &
   $(a t.a)
 ::
+++  murn                                                ::  maybe transform
+  |*  [a=(list) b=$+(* (unit))]
+  %+  reel  a
+  |*  [c=* acc=(list)]
+  =+  i=(b c)
+  ?~  i
+    acc
+  [i=u.i t=acc]
+::
 ++  reel                                                ::  right fold
   ~/  %reel
   |*  [a=(list) b=_|=([* *] +<+)]