From 99ceba43a072f38b2caef8dd74cd1bfc67e517bb Mon Sep 17 00:00:00 2001
From: Neil Cowburn <neilco@gmail.com>
Date: Sat, 1 Feb 2020 08:27:20 +0000
Subject: [PATCH] Add support for snaked-cased hostnames

---
 Database/MongoDB/Connection.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Database/MongoDB/Connection.hs b/Database/MongoDB/Connection.hs
index 5b0823c..0082543 100644
--- a/Database/MongoDB/Connection.hs
+++ b/Database/MongoDB/Connection.hs
@@ -86,7 +86,7 @@ readHostPortM :: (MonadFail m) => String -> m Host
 -- ^ Read string \"hostname:port\" as @Host hosthame (PortNumber port)@ or \"hostname\" as @host hostname@ (default port). Fail if string does not match either syntax.
 -- TODO: handle Service port
 readHostPortM = either (fail . show) return . parse parser "readHostPort" where
-    hostname = many1 (letter <|> digit <|> char '-' <|> char '.')
+    hostname = many1 (letter <|> digit <|> char '-' <|> char '.' <|> char '_')
     parser = do
         spaces
         h <- hostname