From 73aa926bdc8a00b5000a678e63e09e573850bf37 Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@github.com>
Date: Wed, 9 Mar 2016 04:13:09 -0500
Subject: [PATCH] Generalize adjoinRowsBy to any Applicative with an aligning
 function.

---
 src/Alignment.hs      |  6 +++---
 test/AlignmentSpec.hs | 10 +++++-----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/Alignment.hs b/src/Alignment.hs
index 0649cd4b0..7281a76f6 100644
--- a/src/Alignment.hs
+++ b/src/Alignment.hs
@@ -115,6 +115,6 @@ openRange source range = (at source <$> maybeLastIndex range) /= Just '\n'
 type Row a = Both (Line a)
 
 -- | Merge open lines and prepend closed lines (as determined by a pair of functions) onto a list of rows.
-adjoinRowsBy :: Both (a -> Bool) -> Both (Line a) -> [Both (Line a)] -> [Both (Line a)]
-adjoinRowsBy _ row [] = [ row ]
-adjoinRowsBy f row (nextRow : rows) = zipDefaults mempty (coalesceLinesBy <$> f <*> row <*> nextRow) ++ rows
+adjoinRowsBy :: Applicative f => f (a -> Bool) -> (f [Line a] -> [f (Line a)]) -> f (Line a) -> [f (Line a)] -> [f (Line a)]
+adjoinRowsBy _ _ row [] = [ row ]
+adjoinRowsBy f align row (nextRow : rows) = align (coalesceLinesBy <$> f <*> row <*> nextRow) ++ rows
diff --git a/test/AlignmentSpec.hs b/test/AlignmentSpec.hs
index 43a54215e..f1c3fdff2 100644
--- a/test/AlignmentSpec.hs
+++ b/test/AlignmentSpec.hs
@@ -69,20 +69,20 @@ spec = parallel $ do
 
   describe "adjoinRowsBy" $ do
     prop "is identity on top of no rows" $ forAll (arbitrary `suchThat` (not . isEmptyRow)) $
-      \ a -> adjoinRowsBy (pure Maybe.isJust) a [] `shouldBe` [ a :: Row (Maybe Bool) ]
+      \ a -> adjoinRowsBy (pure Maybe.isJust) (zipDefaults mempty) a [] `shouldBe` [ a :: Row (Maybe Bool) ]
 
     prop "prunes empty rows" $
-      \ a -> adjoinRowsBy (pure Maybe.isJust) (both mempty mempty) [ a ] `shouldBe` [ a :: Row (Maybe Bool) ]
+      \ a -> adjoinRowsBy (pure Maybe.isJust) (zipDefaults mempty) (both mempty mempty) [ a ] `shouldBe` [ a :: Row (Maybe Bool) ]
 
     prop "merges open rows" $
       forAll ((arbitrary `suchThat` (and . fmap (isOpenLineBy Maybe.isJust))) >>= \ a -> (,) a <$> arbitrary) $
-        \ (a, b) -> adjoinRowsBy (pure Maybe.isJust) a [ b ] `shouldBe` [ mappend <$> a <*> b :: Row (Maybe Bool) ]
+        \ (a, b) -> adjoinRowsBy (pure Maybe.isJust) (zipDefaults mempty) a [ b ] `shouldBe` [ mappend <$> a <*> b :: Row (Maybe Bool) ]
 
     prop "prepends closed rows" $
-      \ a -> adjoinRowsBy (pure Maybe.isJust) (both (pure Nothing) (pure Nothing)) [ both (pure a) (pure a) ] `shouldBe` [ (both (pure Nothing) (pure Nothing)), both (pure a) (pure a) :: Row (Maybe Bool) ]
+      \ a -> adjoinRowsBy (pure Maybe.isJust) (zipDefaults mempty) (both (pure Nothing) (pure Nothing)) [ both (pure a) (pure a) ] `shouldBe` [ (both (pure Nothing) (pure Nothing)), both (pure a) (pure a) :: Row (Maybe Bool) ]
 
     it "aligns closed lines" $
-      foldr (adjoinRowsBy (pure (/= '\n'))) [] (Prelude.zipWith (both) (pure <$> "[ bar ]\nquux") (pure <$> "[\nbar\n]\nquux")) `shouldBe`
+      foldr (adjoinRowsBy (pure (/= '\n')) (zipDefaults mempty)) [] (Prelude.zipWith (both) (pure <$> "[ bar ]\nquux") (pure <$> "[\nbar\n]\nquux")) `shouldBe`
         [ both (Line "[ bar ]\n") (Line "[\n")
         , both mempty (Line "bar\n")
         , both mempty (Line "]\n")