Pattern match leaf in branches for correct use of 'the'

src/DiffSummary.hs

@@ -83,12 +83,9 @@ summaries patch = eitherErrorOrDoc <$> patchToDoc patch
 -- or `ErrorInfo` it contains.
 patchToDoc :: Patch DiffInfo -> [Doc]
 patchToDoc = \case
-  p@(Replace i1 i2) -> zipWith (\a b -> (prefixWithPatch p) a <+> connector i1 <+> b) (toLeafInfos i1) (toLeafInfos i2)
+  p@(Replace i1 i2) -> zipWith (\a b -> prefixWithPatch p a <+> determiner "with" i1 <+> b) (toLeafInfos i1) (toLeafInfos i2)
   p@(Insert info) -> prefixWithPatch p <$> toLeafInfos info
   p@(Delete info) -> prefixWithPatch p <$> toLeafInfos info
-  where
-    connector (LeafInfo "number" _) = "with"
-    connector _ = "with the"
 
 -- Prefixes a given doc with the type of patch it represents.
 prefixWithPatch :: Patch DiffInfo -> Doc -> Doc
@@ -100,8 +97,18 @@ prefixWithPatch patch = prefixWithThe (patchToPrefix patch)
       (Insert _) -> "Added"
       (Delete _) -> "Deleted"
     connector = \case
-      (Replace (LeafInfo "number" _) _) -> ""
-      _ -> "the"
+      (Replace leaf _) -> determiner' leaf
+      (Insert leaf) -> determiner' leaf
+      (Delete leaf) -> determiner' leaf
+
+-- Optional determiner (e.g. "the") to tie together summary statements.
+determiner :: Doc -> DiffInfo -> Doc
+determiner prefix (LeafInfo "number" _) = prefix <+> ""
+determiner prefix (BranchInfo bs _ _) = determiner prefix (last bs)
+determiner prefix _ = prefix <+> "the"
+
+determiner' :: DiffInfo -> Doc
+determiner' = determiner ""
 
 toLeafInfos :: DiffInfo -> [Doc]
 toLeafInfos (LeafInfo "number" termName) = pure (squotes (toDoc termName))

src/Prologue.hs

@@ -1,10 +1,11 @@
 module Prologue
 ( module X
 , lookup
+, last
 ) where
 
 import Protolude as X
-import Data.List (lookup)
+import Data.List (lookup, last)
 
 import Control.Comonad.Trans.Cofree as X
 import Control.Monad.Trans.Free as X