refine again

[lambda.git] / exercises / assignment8-9.mdwn

diff --git a/exercises/assignment8-9.mdwn b/exercises/assignment8-9.mdwn
index e6d2483..c41ee9b 100644 (file)
--- a/exercises/assignment8-9.mdwn
+++ b/exercises/assignment8-9.mdwn
@@ -33,7 +33,7 @@ you should be able to execute the following expression:
         # match eval t2 with Leaf (Num f) -> f 2 4;;
         - : int = 13
 
         # match eval t2 with Leaf (Num f) -> f 2 4;;
         - : int = 13
 

-2. Based on the evaluator code from the assignment from week 7, and what you've learned about the Reader monad,
+2. Based on [[the evaluator code from assignment 7|/exercises/assignment7/#index3h2]], and what you've learned about the Reader monad,

 enhance the arithmetic tree code to handle an arbitrary set of free variables. Don't use Juli8 libraries for this; just do it by hand.
 Return to the original code (that is, before the modifications required by the previous problem).
 
 enhance the arithmetic tree code to handle an arbitrary set of free variables. Don't use Juli8 libraries for this; just do it by hand.
 Return to the original code (that is, before the modifications required by the previous problem).
 


@@ -137,7 +137,7 @@ Return to the original code (that is, before the modifications required by the p
         -- substitute your own choices for the type Env and value env0
         let { xx :: ReaderT Env Maybe Int; xx = return 1 } in runReaderT xx env0
 
         -- substitute your own choices for the type Env and value env0
         let { xx :: ReaderT Env Maybe Int; xx = return 1 } in runReaderT xx env0
 

-    Okay, here are some questions about various monad transformers. Use OCaml to help you answer them. Which combined monad has the type of an optional list (that is, either `None` or `Some [...]`): an Option transformer wrapped around an underlying List monad, or a List transformer wrapped around an underlying Option monad? Which combined monad has the type of a function from `store`s to a pair `('a list, store)`: a List transformer wrapped around an underlying State monad or a State transformer wrapped around an underlying List monad?
+    Okay, here are some questions about various monad transformers. Use OCaml or Haskell to help you answer them. Which combined monad has the type of an optional list (that is, either `None` or `Some [...]`): an Option transformer wrapped around an underlying List monad, or a List transformer wrapped around an underlying Option monad? Which combined monad has the type of a function from `store`s to a pair `('a list, store)`: a List transformer wrapped around an underlying State monad or a State transformer wrapped around an underlying List monad?

 
 The last two problems are non-monadic.
 
 
 The last two problems are non-monadic.