more description improvements

1 files changed, 6 insertions, 3 deletions

diff --git a/Property.hs b/Property.hs
index 84a57a1b..77a1f502 100644
--- a/Property.hs
+++ b/Property.hs
@@ -43,8 +43,8 @@ propertyList desc ps = Property desc $ ensureProperties' ps
 
 {- Combines a list of properties, resulting in one property that
  - ensures each in turn, stopping on failure. -}
-combineProperties :: Desc -> [Property] -> Property
-combineProperties desc ps = Property desc $ go ps NoChange
+combineProperties :: [Property] -> Property
+combineProperties ps = Property desc $ go ps NoChange
   where
   	go [] rs = return rs
 	go (l:ls) rs = do
@@ -52,6 +52,9 @@ combineProperties desc ps = Property desc $ go ps NoChange
 		case r of
 			FailedChange -> return FailedChange
 			_ -> go ls (combineResult r rs)
+	desc = case ps of
+		(p:_) -> propertyDesc p
+		_ -> "(empty)"
 
 {- Makes a perhaps non-idempotent Property be idempotent by using a flag
  - file to indicate whether it has run before.
@@ -81,7 +84,7 @@ property `onChange` hook = Property (propertyDesc property) $ do
 {- Indicates that the first property can only be satisfied once
  - the second is. -} 
 requires :: Property -> Property -> Property
-x `requires` y = combineProperties (propertyDesc x) [y, x]
+x `requires` y = combineProperties [y, x] `describe` propertyDesc x
 
 describe :: Property -> Desc -> Property
 describe p d = p { propertyDesc = d }