From d6db284c22dce2e932378f7705ad5d496b7a66a2 Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Fri, 15 Nov 2019 19:10:07 +0000
Subject: [PATCH] Improve address range parsing error messages

---
 src/Mima/Parse/FlagFile.hs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/Mima/Parse/FlagFile.hs b/src/Mima/Parse/FlagFile.hs
index 05dd1c7..b221225 100644
--- a/src/Mima/Parse/FlagFile.hs
+++ b/src/Mima/Parse/FlagFile.hs
@@ -31,10 +31,11 @@ lFlags :: Parser (Set.Set Flag)
 lFlags = Set.unions <$> some lFlag
 
 lAddressRange :: Parser AddressRange
-lAddressRange = try twoAddresses <|> oneAddress
-  where
-    twoAddresses = range <$> lAddress <*> (symbol "-" *> lAddress)
-    oneAddress = (\a -> range a a) <$> lAddress -- More fun to read than the do syntax :)
+lAddressRange = do
+  firstAddress <- lAddress
+  secondAddress <- (symbol "-" *> lAddress) <|> pure firstAddress
+  void $ symbol ":"
+  pure $ range firstAddress secondAddress
 
 lLine :: Parser (AddressRange, Set.Set Flag)
 lLine = do