From b1299795166365970a15c6d73b7d9287737d9b0a Mon Sep 17 00:00:00 2001
From: mrkkrp <mark.karpov@tweag.io>
Date: Thu, 23 May 2019 12:18:40 +0200
Subject: [PATCH] Fix guards

---
 .../declaration/value/function/guards-out.hs  | 14 ++++++++++++++
 .../declaration/value/function/guards.hs      | 12 ++++++++++++
 src/Ormolu/Printer/Meat/Declaration/Value.hs  | 19 +++++++++++--------
 3 files changed, 37 insertions(+), 8 deletions(-)
 create mode 100644 data/examples/declaration/value/function/guards-out.hs
 create mode 100644 data/examples/declaration/value/function/guards.hs

diff --git a/data/examples/declaration/value/function/guards-out.hs b/data/examples/declaration/value/function/guards-out.hs
new file mode 100644
index 0000000..ef57761
--- /dev/null
+++ b/data/examples/declaration/value/function/guards-out.hs
@@ -0,0 +1,14 @@
+foo :: Int -> Int
+foo x
+  | x == 5 = 10
+  | otherwise = 12
+
+bar :: Int -> Int
+bar x
+  | x == 5 =
+    foo x
+      + foo 10
+  | x == 6 =
+    foo x
+      + foo 20
+  | otherwise = foo 100
diff --git a/data/examples/declaration/value/function/guards.hs b/data/examples/declaration/value/function/guards.hs
new file mode 100644
index 0000000..7f71f62
--- /dev/null
+++ b/data/examples/declaration/value/function/guards.hs
@@ -0,0 +1,12 @@
+foo :: Int -> Int
+foo x
+  | x == 5 = 10
+  | otherwise = 12
+
+bar :: Int -> Int
+bar x
+  | x == 5 = foo x
+       + foo 10
+  | x == 6 = foo x
+       + foo 20
+  | otherwise = foo 100
diff --git a/src/Ormolu/Printer/Meat/Declaration/Value.hs b/src/Ormolu/Printer/Meat/Declaration/Value.hs
index c620c29..ff9397f 100644
--- a/src/Ormolu/Printer/Meat/Declaration/Value.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Value.hs
@@ -80,10 +80,10 @@ p_match style Match {..} = do
         inci' (velt' (located' p_pat <$> m_pats))
       return inci'
   inci' $ do
-    space
     let GRHSs {..} = m_grhss
-    unless (length grhssGRHSs > 1) . txt $
-      case style of
+    unless (length grhssGRHSs > 1) $ do
+      space
+      txt $ case style of
         Function _ -> "="
         _ -> "->"
     let combinedSpans = combineSrcSpans' $
@@ -101,9 +101,6 @@ p_match style Match {..} = do
         line (txt "where")
         inci (located grhssLocalBinds p_hsLocalBinds)
 
-getGRHSSpan :: GRHS GhcPs (LHsExpr GhcPs) -> SrcSpan
-getGRHSSpan (GRHS _ body) = getSpan body
-
 p_grhs :: GRHS GhcPs (LHsExpr GhcPs) -> R ()
 p_grhs (GRHS guards body) =
   case guards of
@@ -111,9 +108,9 @@ p_grhs (GRHS guards body) =
     xs -> do
       txt "| "
       velt $ withSep comma (located' p_stmt) xs
-      txt " ->"
+      txt " ="
       breakpoint
-      p_body
+      inci p_body
   where
     p_body = located body p_hsExpr
 
@@ -237,3 +234,9 @@ p_hsExpr = \case
   EViewPat {} -> notImplemented "EViewPat"
   ELazyPat {} -> notImplemented "ELazyPat"
   HsWrap {} -> notImplemented "HsWrap"
+
+----------------------------------------------------------------------------
+-- Helpers
+
+getGRHSSpan :: GRHS GhcPs (LHsExpr GhcPs) -> SrcSpan
+getGRHSSpan (GRHS _ body) = getSpan body