From: Matthijs Kooijman <m.kooijman@student.utwente.nl>
Date: Thu, 19 Feb 2009 12:11:24 +0000 (+0100)
Subject: Let zipValueMapsWith show the trees in the error.
X-Git-Url: https://git.stderr.nl/gitweb?a=commitdiff_plain;h=f445c30c4a089e8898fd1438747b3c7e33547890;p=matthijs%2Fmaster-project%2Fc%CE%BBash.git

Let zipValueMapsWith show the trees in the error.
---

diff --git a/HsValueMap.hs b/HsValueMap.hs
index 97e4cdb..f4498f2 100644
--- a/HsValueMap.hs
+++ b/HsValueMap.hs
@@ -57,15 +57,16 @@ mkHsValueMap ty =
 
 -- | Creates a map of pairs from two maps. The maps must have the same
 --   structure.
-zipValueMaps :: HsValueMap a -> HsValueMap b -> HsValueMap (a, b)
+zipValueMaps :: (Show a, Show b) => HsValueMap a -> HsValueMap b -> HsValueMap (a, b)
 zipValueMaps = zipValueMapsWith (\a b -> (a, b))
 
 -- | Creates a map of two maps using the given combination function.
-zipValueMapsWith :: (a -> b -> c) -> HsValueMap a -> HsValueMap b -> HsValueMap c
+zipValueMapsWith :: (Show a, Show b) => (a -> b -> c) -> HsValueMap a -> HsValueMap b -> HsValueMap c
 zipValueMapsWith f (Tuple as) (Tuple bs) =
   Tuple $ zipWith (zipValueMapsWith f) as bs
 zipValueMapsWith f (Single a) (Single b) =
   Single $ f a b
-zipValueMapWith _ _ _ =
-  error $ "Trying to zip unsimilarly formed trees!"
+zipValueMapsWith _ a b =
+  --Tuple []
+  error $ "Trying to zip unsimilarly formed trees!\n" ++ (show a) ++ "\nand\n" ++ (show b)