From be3f43702b665af46e033e419659ba8a0ea0d5df Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@github.com>
Date: Tue, 28 Jun 2016 15:01:02 -0400
Subject: [PATCH] Replace incomparable terms.

---
 src/Data/RandomWalkSimilarity.hs | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/Data/RandomWalkSimilarity.hs b/src/Data/RandomWalkSimilarity.hs
index 03d9a37eb..ba45ff8b1 100644
--- a/src/Data/RandomWalkSimilarity.hs
+++ b/src/Data/RandomWalkSimilarity.hs
@@ -25,6 +25,7 @@ rws compare getLabel as bs
   | otherwise = uncurry deleteRemaining . (`runState` Set.empty) $ traverse findNearestNeighbourTo (featurize <$> bs)
   where insert = pure . Insert
         delete = pure . Delete
+        replace = (pure .) . Replace
         (p, q) = (2, 2)
         d = 15
         fas = featurize <$> as
@@ -35,11 +36,12 @@ rws compare getLabel as bs
           let (k, nearest) = KdTree.nearest kdas kv
           if k `Set.member` mapped
             then pure $! insert v
-            else case compare nearest v of
-              Just y -> do
-                put (Set.insert k mapped)
-                pure y
-              _ -> pure $! delete v
+            else do
+              put (Set.insert k mapped)
+              case compare nearest v of
+                Just y -> do
+                  pure y
+                _ -> pure $! replace nearest v
         deleteRemaining diff mapped = diff <> (delete . snd <$> filter (not . (`Set.member` mapped) . fst) fas)
 
 data Gram label = Gram { stem :: [Maybe label], base :: [Maybe label] }