From 3847325fd5a9413037c73f919a92772cbfe2f57c Mon Sep 17 00:00:00 2001
From: Lennart Spitzner <hexagoxel@hexagoxel.de>
Date: Fri, 23 Mar 2018 17:02:58 +0100
Subject: [PATCH] Omit single-line layout for OpApp with comments (fixes #111)

---
 src-literatetests/15-regressions.blt          | 12 +++++++
 .../Brittany/Internal/Layouters/Expr.hs       | 31 +++++++++++--------
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src-literatetests/15-regressions.blt b/src-literatetests/15-regressions.blt
index 91038fc..2127eaf 100644
--- a/src-literatetests/15-regressions.blt
+++ b/src-literatetests/15-regressions.blt
@@ -538,6 +538,18 @@ cs0 = 0 : [ c / Interval n | c <- cs | n <- [1..] ]
 {-# LANGUAGE TemplateHaskell #-}
 deriveFromJSON (unPrefix "assignPost") ''AssignmentPost
 
+#test issue 111
+
+alternatives :: Parser (Maybe Text)
+alternatives =
+  alternativeOne   -- first try this one
+    <|> alterantiveTwo   -- then this one
+    <|> alternativeThree -- then this one
+ where
+  alternativeOne   = purer "one"
+  alternativeTwo   = purer "two"
+  alterantiveThree = purer "three"
+
 #test issue 116
 {-# LANGUAGE BangPatterns #-}
 func = do
diff --git a/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs b/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs
index d144b80..98d3d10 100644
--- a/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs
+++ b/src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs
@@ -237,24 +237,27 @@ layoutExpr lexpr@(L _ expr) = do
                                               ]
       opLastDoc <- docSharedWrapper layoutExpr expOp
       expLastDoc <- docSharedWrapper layoutExpr expRight
+      hasComments <- hasAnyCommentsBelow lexpr
       let allowPar = case (expOp, expRight) of
             (L _ (HsVar (L _ (Unqual occname))), _)
               | occNameString occname == "$" -> True
             (_, L _ (HsApp _ (L _ HsVar{}))) -> False
             _ -> True
-      docAlt
-        [ docSeq
-          [ appSep $ docForceSingleline leftOperandDoc
+      docAltFilter
+        [ ( not hasComments
           , docSeq
-          $ (appListDocs <&> \(od, ed) -> docSeq
-              [ appSep $ docForceSingleline od
-              , appSep $ docForceSingleline ed
-              ]
-            )
-          , appSep $ docForceSingleline opLastDoc
-          , (if allowPar then docForceParSpacing else docForceSingleline)
-              expLastDoc
-          ]
+            [ appSep $ docForceSingleline leftOperandDoc
+            , docSeq
+            $ (appListDocs <&> \(od, ed) -> docSeq
+                [ appSep $ docForceSingleline od
+                , appSep $ docForceSingleline ed
+                ]
+              )
+            , appSep $ docForceSingleline opLastDoc
+            , (if allowPar then docForceParSpacing else docForceSingleline)
+                expLastDoc
+            ]
+          )
         -- this case rather leads to some unfortunate layouting than to anything
         -- useful; disabling for now. (it interfers with cols stuff.)
         -- , docSetBaseY
@@ -264,12 +267,14 @@ layoutExpr lexpr@(L _ expr) = do
         -- -    $ (appListDocs <&> \(od, ed) -> docCols ColOpPrefix [appSep od, docSetBaseY ed])
         --       ++ [docCols ColOpPrefix [appSep opLastDoc, docSetBaseY expLastDoc]]
         --     )
-        , docPar
+        , (otherwise
+          , docPar
             leftOperandDoc
             ( docLines
             $ (appListDocs <&> \(od, ed) -> docCols ColOpPrefix [appSep od, docSetBaseY ed])
               ++ [docCols ColOpPrefix [appSep opLastDoc, docSetBaseY expLastDoc]]
             )
+          )
         ]
     OpApp expLeft expOp _ expRight -> do
       expDocLeft  <- docSharedWrapper layoutExpr expLeft