improve showR

Author: MaximilianAlgehed

quickcheck-dynamic/src/Test/QuickCheck/ParallelActions.hs

@@ -170,18 +170,19 @@ monitorTrace :: forall state m. (StateModel state, RunModelPar state m)
              => VarContext -> Env -> Trace state m -> PropertyM m ()
 monitorTrace _used _env [] = pure ()
 monitorTrace used env (TraceStep r v act : tr) = do
-  let showR (Right x) = show x
+  let showR (Right x)
+        | v `wellTypedIn` used = show v ++ "@" ++ showsPrec 10 x ""
+        | otherwise = show x
       showR (Left err) = "fail " ++ showsPrec 10 err ""
-      pre | v `wellTypedIn` used = show v ++ " @ "
-          | otherwise = ""
-  monitor $ counterexample (pre ++ showR r ++ " <- " ++ show (polarAction act))
+  monitor $ counterexample (showR r ++ " <- " ++ show (polarAction act))
   monitor $ monitoringPar @state @m (polarAction act) (lookUpVar env) r
   monitorTrace used env' tr
   where
     env' | Right val <- r = (v :== val) : env
          | otherwise      = env
 
-checkTrace :: forall state m. (StateModel state, RunModelPar state m) => Annotated state -> Env -> TraceTree state m -> Bool
+checkTrace :: forall state m. (StateModel state, RunModelPar state m)
+           => Annotated state -> Env -> TraceTree state m -> Bool
 checkTrace s env (Node (TraceStep r v (ActionWithPolarity a _)) trs) =
   -- NOTE: we need to re-compute the polarity of `a` here because it may be that the failure can be explained,
   -- but only by the action failing when it was previous successful