From 6ac1574ad186921e3f26681bc61228ff37443463 Mon Sep 17 00:00:00 2001
From: Oleg Grenrus <oleg.grenrus@iki.fi>
Date: Fri, 14 Feb 2020 12:15:56 +0200
Subject: [PATCH] Add doctests for Parsec PkgconfigVersion

Related to https://github.com/haskell/cabal/issues/6539
---
 Cabal/Distribution/Types/PkgconfigVersion.hs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Cabal/Distribution/Types/PkgconfigVersion.hs b/Cabal/Distribution/Types/PkgconfigVersion.hs
index ec5145becfb..e79fefb9e5f 100644
--- a/Cabal/Distribution/Types/PkgconfigVersion.hs
+++ b/Cabal/Distribution/Types/PkgconfigVersion.hs
@@ -40,6 +40,14 @@ instance NFData PkgconfigVersion where rnf = genericRnf
 instance Pretty PkgconfigVersion where
     pretty (PkgconfigVersion bs) = PP.text (BS8.unpack bs)
 
+-- |
+--
+-- >>> simpleParsec "1.0.2n" :: Maybe PkgconfigVersion
+-- Just (PkgconfigVersion "1.0.2n")
+--
+-- >>> simpleParsec "0.3.5+ds" :: Maybe PkgconfigVersion
+-- Nothing
+--
 instance Parsec PkgconfigVersion where
     parsec = PkgconfigVersion . BS8.pack <$> P.munch1 predicate where
         predicate c = isAsciiAlphaNum c || c == '.' || c == '-'