From 00c3a2ef9f665c5605b2fd221d8a682041b64210 Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@github.com>
Date: Fri, 18 Mar 2016 12:01:59 -0400
Subject: [PATCH] Spike out a function aligning Terms in Patches.

---
 src/Alignment.hs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/Alignment.hs b/src/Alignment.hs
index d31fde168..3a7a11492 100644
--- a/src/Alignment.hs
+++ b/src/Alignment.hs
@@ -14,6 +14,7 @@ import Control.Monad
 import Control.Monad.Free
 import Data.Adjoined
 import Data.Align
+import Data.Aligned
 import Data.Bifunctor.These
 import Data.Coalescent
 import Data.Copointed
@@ -108,6 +109,13 @@ type Row a = Both (Line a)
 -- | A fixpoint over a functor.
 newtype Fix f = Fix { unFix :: f (Fix f) }
 
+alignPatch :: Patch (Term leaf Info) -> Fix (Aligned (Syntax leaf))
+alignPatch (Insert term) = hylo (Fix . AlignThis . pure) unwrap term
+alignPatch (Delete term) = hylo (Fix . AlignThat . pure) unwrap term
+alignPatch (Replace term1 term2) = let Fix (AlignThis a) = alignPatch $ Delete term1
+                                       Fix (AlignThat b) = alignPatch $ Insert term2 in
+                                       Fix (AlignThese a b)
+
 hylo :: Functor f => (f b -> b) -> (a -> f a) -> a -> b
 hylo phi psi = Alignment.cata phi . ana psi