slightly less dilly-dallying

Author: MaximilianAlgehed

src/Constrained/GenT.hs

@@ -110,7 +110,9 @@ data GenMode
 -- | A `Gen` monad wrapper that allows different generation modes and different
 -- failure types.
 newtype GenT m a = GenT {runGenT :: GenMode -> [NonEmpty String] -> Gen (m a)}
-  deriving (Functor)
+
+instance Functor f => Functor (GenT f) where
+  fmap f (GenT k) = GenT $ \ mode msgs -> fmap (fmap f) (k mode msgs)
 
 instance Monad m => Applicative (GenT m) where
   pure a = GenT (\_ _ -> pure @Gen (pure @m a))

src/Constrained/Generation.hs

@@ -128,7 +128,7 @@ genFromSpecT (simplifySpec -> spec) = case spec of
 
 -- | A version of `genFromSpecT` that simply errors if the generator fails
 genFromSpec :: forall a. (HasCallStack, HasSpec a) => Specification a -> Gen a
-genFromSpec spec = either (error . ('\n' :) . catMessages) id <$> catchGen (genFromSpecT @a @GE spec)
+genFromSpec spec = genFromGenT (genFromSpecT @a @GE spec)
 
 -- | A version of `genFromSpecT` that takes a seed and a size and gives you a result
 genFromSpecWithSeed ::