From 56e7d6b5b9d19760dcc356c03d73f203fcc25b9d Mon Sep 17 00:00:00 2001
From: Lennart Spitzner <hexagoxel@hexagoxel.de>
Date: Thu, 20 Apr 2023 17:05:57 +0000
Subject: [PATCH] Simplify/Optimize Decl:layoutPatternBindFinal

---
 .../Brittany/Internal/ToBriDoc/Decl.hs        | 71 +++++++------------
 1 file changed, 24 insertions(+), 47 deletions(-)

diff --git a/source/library/Language/Haskell/Brittany/Internal/ToBriDoc/Decl.hs b/source/library/Language/Haskell/Brittany/Internal/ToBriDoc/Decl.hs
index 884262c..7f177f0 100644
--- a/source/library/Language/Haskell/Brittany/Internal/ToBriDoc/Decl.hs
+++ b/source/library/Language/Haskell/Brittany/Internal/ToBriDoc/Decl.hs
@@ -412,6 +412,8 @@ layoutPatternBindFinal alignmentToken binderDoc mPatDoc clauses (wrapBinds, mWhe
         pure [(Nothing, [], e)]
       Right grhss -> layoutGrhs `mapM` grhss
 
+    let multipleClauses = not $ null clauseDocs
+
     runFilteredAlternative $ do
 
       case clauseDocs of
@@ -492,12 +494,11 @@ layoutPatternBindFinal alignmentToken binderDoc mPatDoc clauses (wrapBinds, mWhe
         _ -> return () -- no alternatives exclusively when `length clauseDocs /= 1`
 
       case mPatDoc of
-        Nothing -> return ()
-        Just patDoc ->
+        Just patDoc | multipleClauses, indentPolicy == IndentPolicyFree ->
           -- multiple clauses added in-paragraph, each in a single line
           -- example: foo | bar = baz
           --              | lll = asd
-          addAlternativeCond (indentPolicy == IndentPolicyFree)
+          addAlternative
             $ docLines
             $ [ docSeq
                   [ appSep $ docForceSingleline $ return patDoc
@@ -522,6 +523,7 @@ layoutPatternBindFinal alignmentToken binderDoc mPatDoc clauses (wrapBinds, mWhe
                   ]
               ]
             ++ wherePartMultiLine
+        _ -> return ()
       -- multiple clauses, each in a separate, single line
       addAlternative
         $ docLines
@@ -558,29 +560,16 @@ layoutPatternBindFinal alignmentToken binderDoc mPatDoc clauses (wrapBinds, mWhe
             $ map docSetBaseY
             $ clauseDocs
             <&> \(grhsEpAnn, guardDocs, bodyDoc) -> -- TODO92
-                  docHandleComms grhsEpAnn $ docSeq
-                    $ (case guardDocs of
-                        [] -> []
-                        [g] ->
-                          [ docForceSingleline $ docSeq
-                              [appSep $ docLit $ Text.pack "|", return g]
-                          ]
-                        gs ->
-                          [ docForceSingleline
-                              $ docSeq
-                              $ [appSep $ docLit $ Text.pack "|"]
-                              ++ List.intersperse docCommaSep (return <$> gs)
-                          ]
-                      )
-                    ++ [ docSeparator
-                       , docCols
-                         ColOpPrefix
-                         [ appSep $ return binderDoc
-                         , docAddBaseY BrIndentRegular
-                         $ docForceParSpacing
-                         $ return bodyDoc
-                         ]
-                       ]
+              docHandleComms grhsEpAnn $ docSeq
+                [ singleLineGuardsDoc guardDocs
+                , docCols
+                  ColOpPrefix
+                  [ appSep $ return binderDoc
+                  , docAddBaseY BrIndentRegular
+                  $ docForceParSpacing
+                  $ return bodyDoc
+                  ]
+                ]
           ]
         ++ wherePartMultiLine
       -- multiple clauses, each with the guard(s) in a single line, body
@@ -593,27 +582,15 @@ layoutPatternBindFinal alignmentToken binderDoc mPatDoc clauses (wrapBinds, mWhe
             $ map docSetBaseY
             $ clauseDocs
             >>= \(grhsEpAnn, guardDocs, bodyDoc) -> -- TODO92
-                  (case guardDocs of
-                      [] -> [docHandleComms grhsEpAnn docEmpty]
-                      [g] ->
-                        [ docHandleComms grhsEpAnn $ docForceSingleline
-                            $ docSeq [appSep $ docLit $ Text.pack "|", return g]
-                        ]
-                      gs ->
-                        [ docHandleComms grhsEpAnn $ docForceSingleline
-                            $ docSeq
-                            $ [appSep $ docLit $ Text.pack "|"]
-                            ++ List.intersperse docCommaSep (return <$> gs)
-                        ]
-                    )
-                    ++ [ docCols
-                           ColOpPrefix
-                           [ appSep $ return binderDoc
-                           , docAddBaseY BrIndentRegular
-                           $ docForceParSpacing
-                           $ return bodyDoc
-                           ]
-                       ]
+              [ docHandleComms grhsEpAnn $ singleLineGuardsDoc guardDocs
+              , docCols
+                ColOpPrefix
+                [ appSep $ return binderDoc
+                , docAddBaseY BrIndentRegular
+                $ docForceParSpacing
+                $ return bodyDoc
+                ]
+              ]
           ]
         ++ wherePartMultiLine
       -- conservative approach: everything starts on the left.