From dfbb68357358d7a49bdb056ed322831ae8cf6475 Mon Sep 17 00:00:00 2001
From: Hans-Peter Deifel <hpd@hpdeifel.de>
Date: Fri, 13 Jan 2017 22:10:11 +0100
Subject: [PATCH] Prettify option parsing errors (#478)

Megaparsec's show instance for ParseError doesn't produce digestible
strings. parseErrorPretty has to be used instead.
---
 hledger-lib/Hledger/Reports/ReportOptions.hs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/hledger-lib/Hledger/Reports/ReportOptions.hs b/hledger-lib/Hledger/Reports/ReportOptions.hs
index 5d4bef26d..9c438dbec 100644
--- a/hledger-lib/Hledger/Reports/ReportOptions.hs
+++ b/hledger-lib/Hledger/Reports/ReportOptions.hs
@@ -41,6 +41,7 @@ import Data.Time.Calendar
 import Data.Default
 import Safe
 import Test.HUnit
+import Text.Megaparsec.Error
 
 import Hledger.Data
 import Hledger.Query
@@ -207,11 +208,11 @@ beginDatesFromRawOpts d = catMaybes . map (begindatefromrawopt d)
   where
     begindatefromrawopt d (n,v)
       | n == "begin" =
-          either (\e -> optserror $ "could not parse "++n++" date: "++show e) Just $
+          either (\e -> optserror $ "could not parse "++n++" date: "++parseErrorPretty e) Just $
           fixSmartDateStrEither' d (T.pack v)
       | n == "period" =
         case
-          either (\e -> optserror $ "could not parse period option: "++show e) id $
+          either (\e -> optserror $ "could not parse period option: "++parseErrorPretty e) id $
           parsePeriodExpr d (stripquotes $ T.pack v)
         of
           (_, DateSpan (Just b) _) -> Just b
@@ -225,11 +226,11 @@ endDatesFromRawOpts d = catMaybes . map (enddatefromrawopt d)
   where
     enddatefromrawopt d (n,v)
       | n == "end" =
-          either (\e -> optserror $ "could not parse "++n++" date: "++show e) Just $
+          either (\e -> optserror $ "could not parse "++n++" date: "++parseErrorPretty e) Just $
           fixSmartDateStrEither' d (T.pack v)
       | n == "period" =
         case
-          either (\e -> optserror $ "could not parse period option: "++show e) id $
+          either (\e -> optserror $ "could not parse period option: "++parseErrorPretty e) id $
           parsePeriodExpr d (stripquotes $ T.pack v)
         of
           (_, DateSpan _ (Just e)) -> Just e
@@ -243,7 +244,7 @@ intervalFromRawOpts = lastDef NoInterval . catMaybes . map intervalfromrawopt
   where
     intervalfromrawopt (n,v)
       | n == "period" =
-          either (\e -> optserror $ "could not parse period option: "++show e) (Just . fst) $
+          either (\e -> optserror $ "could not parse period option: "++parseErrorPretty e) (Just . fst) $
           parsePeriodExpr nulldate (stripquotes $ T.pack v) -- reference date does not affect the interval
       | n == "daily"     = Just $ Days 1
       | n == "weekly"    = Just $ Weeks 1