From ad3c5dfb4d6202f6794906e1e45c47bbd0bc14be Mon Sep 17 00:00:00 2001
From: Simon Michael <simon@joyful.com>
Date: Fri, 27 May 2016 08:06:53 -0700
Subject: [PATCH] lib: fix ghc 8-related date issues (#352)

 Our null date is now 0000/01/01 instead of 0000/00/00.
---
 hledger-lib/Hledger/Data/Dates.hs | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/hledger-lib/Hledger/Data/Dates.hs b/hledger-lib/Hledger/Data/Dates.hs
index 945fa5c57..9711a4f3b 100644
--- a/hledger-lib/Hledger/Data/Dates.hs
+++ b/hledger-lib/Hledger/Data/Dates.hs
@@ -550,13 +550,25 @@ parsedateM s = firstJust [
 --
 -- >>> parsedate "2008/02/03"
 -- 2008-02-03
--- >>> parsedate "2008/02/03/"
--- *** Exception: could not parse date "2008/02/03/"
--- >>> parsedate "2008/02/30"  -- invalid dates may get silently adjusted
--- 2008-02-29
 parsedate :: String -> Day
 parsedate s =  fromMaybe (error' $ "could not parse date \"" ++ s ++ "\"")
                          (parsedateM s)
+-- doctests I haven't been able to make compatible with both GHC 7 and 8
+-- -- >>> parsedate "2008/02/03/"
+-- -- *** Exception: could not parse date "2008/02/03/"
+-- #if MIN_VERSION_base(4,9,0)
+-- -- ...
+-- #endif
+-- #if MIN_VERSION_time(1,6,0)
+-- -- >>> parsedate "2008/02/30"  -- with time >= 1.6, invalid dates are rejected
+-- -- *** Exception: could not parse date "2008/02/30"
+-- #if MIN_VERSION_base(4,9,0)
+-- -- ...
+-- #endif
+-- #else
+-- -- >>> parsedate "2008/02/30"  -- with time < 1.6, they are silently adjusted
+-- -- 2008-02-29
+-- #endif
 
 -- | Parse a time string to a time type using the provided pattern, or
 -- return the default.
@@ -855,4 +867,4 @@ nulldatespan :: DateSpan
 nulldatespan = DateSpan Nothing Nothing
 
 nulldate :: Day
-nulldate = parsedate "0000/00/00"
+nulldate = fromGregorian 0 1 1