From 35f33c131cea6e9918dda0d937c997cf7aea8a3d Mon Sep 17 00:00:00 2001
From: Evan Rutledge Borden <eborden@frontrowed.com>
Date: Sat, 25 Nov 2017 20:24:41 -0500
Subject: [PATCH] Remove duplication in 'let' expression layout.

---
 .../Brittany/Internal/Layouters/Expr.hs       | 100 ++++++++----------
 1 file changed, 46 insertions(+), 54 deletions(-)

diff --git a/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs b/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs
index 86e86ac..c3f4429 100644
--- a/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs
+++ b/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs
@@ -567,65 +567,57 @@ layoutExpr lexpr@(L _ expr) = do
               (docSetBaseY $ expDoc1)
             ]
           ]
-        Just bindDocs@(_:_) -> docAlt $
-          case indentPolicy of
-            IndentPolicyLeft ->
-              --either
-              --  let
-              --    a = b
-              --    c = d
-              --  in foo
-              --    bar
-              --    baz
-              --or
-              --  let
-              --    a = b
-              --    c = d
-              --  in
-              --    fooooooooooooooooooo
-              [ docLines
-                [ docAddBaseY BrIndentRegular
-                $ docPar
-                  (docLit $ Text.pack "let")
-                  (docSetBaseAndIndent $ docLines $ return <$> bindDocs)
-                , docSeq
-                  [ docLit $ Text.pack "in "
-                  , docAddBaseY BrIndentRegular $ expDoc1
-                  ]
-                ]
-              , docLines
-                [ docAddBaseY BrIndentRegular
-                $ docPar
-                  (docLit $ Text.pack "let")
-                  (docSetBaseAndIndent $ docLines $ return <$> bindDocs)
-                , docAddBaseY BrIndentRegular
-                $ docPar
-                  (docLit $ Text.pack "in")
-                  (docSetBaseY $ expDoc1)
+        Just bindDocs@(_:_) -> docAltFilter
+          --either
+          --  let
+          --    a = b
+          --    c = d
+          --  in foo
+          --    bar
+          --    baz
+          --or
+          --  let
+          --    a = b
+          --    c = d
+          --  in
+          --    fooooooooooooooooooo
+          [ ( indentPolicy == IndentPolicyLeft
+            , docLines
+              [ docAddBaseY BrIndentRegular
+              $ docPar
+                (docLit $ Text.pack "let")
+                (docSetBaseAndIndent $ docLines $ return <$> bindDocs)
+              , docSeq
+                [ docLit $ Text.pack "in "
+                , docAddBaseY BrIndentRegular $ expDoc1
                 ]
               ]
-            _ ->
-              [ docLines
-                [ docSeq
-                  [ appSep $ docLit $ Text.pack "let"
-                  , docSetBaseAndIndent $ docLines $ return <$> bindDocs
-                  ]
-                , docSeq
-                  [ appSep $ docLit $ Text.pack "in "
-                  , docSetBaseY $ expDoc1
-                  ]
+            )
+          , ( indentPolicy /= IndentPolicyLeft
+            , docLines
+              [ docSeq
+                [ appSep $ docLit $ Text.pack "let"
+                , docSetBaseAndIndent $ docLines $ return <$> bindDocs
                 ]
-              , docLines
-                [ docAddBaseY BrIndentRegular
-                $ docPar
-                  (docLit $ Text.pack "let")
-                  (docSetBaseAndIndent $ docLines $ return <$> bindDocs)
-                , docAddBaseY BrIndentRegular
-                $ docPar
-                  (docLit $ Text.pack "in")
-                  (docSetBaseY $ expDoc1)
+              , docSeq
+                [ appSep $ docLit $ Text.pack "in "
+                , docSetBaseY $ expDoc1
                 ]
               ]
+            )
+          , ( True
+            , docLines
+              [ docAddBaseY BrIndentRegular
+              $ docPar
+                (docLit $ Text.pack "let")
+                (docSetBaseAndIndent $ docLines $ return <$> bindDocs)
+              , docAddBaseY BrIndentRegular
+              $ docPar
+                (docLit $ Text.pack "in")
+                (docSetBaseY $ expDoc1)
+              ]
+            )
+          ]
         _ -> docSeq [appSep $ docLit $ Text.pack "let in", expDoc1]
       -- docSeq [appSep $ docLit "let in", expDoc1]
     HsDo DoExpr (L _ stmts) _ -> do