From 79ceb7962fd326e412946d2b68b478bcd6b11ab5 Mon Sep 17 00:00:00 2001
From: mrkkrp <markkarpov@opmbx.org>
Date: Thu, 15 Oct 2015 15:12:28 +0600
Subject: [PATCH] eliminate indentation in error messages
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Indented text returned by ‘showMessages’ may be undesirable, but we
cannot add indentation outside of the function (edge case: strings
including newline are displayed in the messages).
---
 Text/Megaparsec/Char.hs  |  4 ++--
 Text/Megaparsec/Error.hs |  4 ++--
 Text/Megaparsec/Prim.hs  | 16 ++++++++--------
 old-tests/Bugs/Bug6.hs   |  2 +-
 old-tests/Bugs/Bug9.hs   |  2 +-
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/Text/Megaparsec/Char.hs b/Text/Megaparsec/Char.hs
index 5db9bec..b8b324a 100644
--- a/Text/Megaparsec/Char.hs
+++ b/Text/Megaparsec/Char.hs
@@ -257,8 +257,8 @@ char c = satisfy (== c) <?> showToken c
 -- 'E'
 -- >>> parseTest (char' 'e') "G"
 -- 1:1:
---   unexpected 'G'
---   expecting 'E' or 'e'
+-- unexpected 'G'
+-- expecting 'E' or 'e'
 
 char' :: MonadParsec s m Char => Char -> m Char
 char' = choice . fmap char . extendi . pure
diff --git a/Text/Megaparsec/Error.hs b/Text/Megaparsec/Error.hs
index 068e931..9ebf81e 100644
--- a/Text/Megaparsec/Error.hs
+++ b/Text/Megaparsec/Error.hs
@@ -169,12 +169,12 @@ mergeError e1@(ParseError pos1 _) e2@(ParseError pos2 ms2) =
 -- their textual representation.
 
 showMessages :: [Message] -> String
-showMessages [] = "  unknown parse error"
+showMessages [] = "unknown parse error"
 showMessages ms = tail $ foldMap (fromMaybe "") (zipWith f ns rs)
   where (unexpected,    ms') = span ((== 0) . fromEnum) ms
         (expected, messages) = span ((== 1) . fromEnum) ms'
         f prefix m = (prefix ++) <$> m
-        ns = ["\n  unexpected ","\n  expecting ","\n  "]
+        ns = ["\nunexpected ","\nexpecting ","\n"]
         rs = renderMsgs <$> [unexpected, expected, messages]
 
 -- | Render collection of messages. If the collection is empty, return
diff --git a/Text/Megaparsec/Prim.hs b/Text/Megaparsec/Prim.hs
index abc1fa9..18ae5c3 100644
--- a/Text/Megaparsec/Prim.hs
+++ b/Text/Megaparsec/Prim.hs
@@ -140,15 +140,15 @@ data Reply s a = Ok a !(State s) | Error ParseError
 --
 -- >>> parseTest (many (char 'r') <* eof) "ra"
 -- 1:2:
---   unexpected 'a'
---   expecting end of input
+-- unexpected 'a'
+-- expecting end of input
 --
 -- We're getting better error messages with help of hints:
 --
 -- >>> parseTest (many (char 'r') <* eof) "ra"
 -- 1:2:
---   unexpected 'a'
---   expecting 'r' or end of input
+-- unexpected 'a'
+-- expecting 'r' or end of input
 
 newtype Hints = Hints [[String]] deriving Monoid
 
@@ -385,8 +385,8 @@ class (A.Alternative m, Monad m, Stream s t)
   --
   -- >>> parseTest (string "let" <|> string "lexical") "lexical"
   -- 1:1:
-  --   unexpected "lex"
-  --   expecting "let"
+  -- unexpected "lex"
+  -- expecting "let"
   --
   -- What happens here? First parser consumes “le” and fails (because it
   -- doesn't see a “t”). The second parser, however, isn't tried, since the
@@ -401,8 +401,8 @@ class (A.Alternative m, Monad m, Stream s t)
   --
   -- >>> parseTest (try (string "let") <|> string "lexical") "le"
   -- 1:1:
-  --   unexpected "le"
-  --   expecting "let" or "lexical"
+  -- unexpected "le"
+  -- expecting "let" or "lexical"
 
   try :: m a -> m a
 
diff --git a/old-tests/Bugs/Bug6.hs b/old-tests/Bugs/Bug6.hs
index 8a6b947..fc8f736 100644
--- a/old-tests/Bugs/Bug6.hs
+++ b/old-tests/Bugs/Bug6.hs
@@ -13,7 +13,7 @@ import Util
 main :: Test
 main =
   testCase "Look-ahead preserving error location (#6)" $
-  parseErrors variable "return" @?= ["  'return' is a reserved keyword"]
+  parseErrors variable "return" @?= ["'return' is a reserved keyword"]
 
 variable :: Parser String
 variable = do
diff --git a/old-tests/Bugs/Bug9.hs b/old-tests/Bugs/Bug9.hs
index 7282e83..6f2b607 100644
--- a/old-tests/Bugs/Bug9.hs
+++ b/old-tests/Bugs/Bug9.hs
@@ -24,7 +24,7 @@ data Expr = Const Integer | Op Expr Expr deriving Show
 main :: Test
 main =
   testCase "Tracing of current position in error message (#9)"
-  $ result @?= ["  unexpected '>'", "  expecting end of input or operator"]
+  $ result @?= ["unexpected '>'", "expecting end of input or operator"]
   where
     result :: [String]
     result = parseErrors parseTopLevel "4 >> 5"