mtl-2.3.1 compatibility (GHC 9.6): import Control.Monad

mtl-2.3.1 removed some reexports, so `Control.Monad.Writer` does not include `Control.Monad` anymore. This patch should make happy 1.20 work with GHC 9.6 which ships with mtl-2.3.1.
haskell · Jan 23, 2023 · 7efed23 · 7efed23
1 parent 3aec2ef
commit 7efed23
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/Grammar.lhs b/src/Grammar.lhs
@@ -30,7 +30,8 @@ Here is our mid-section datatype
 > import Data.List
 > import Data.Maybe (fromMaybe)
 
-> import Control.Monad.Writer
+> import Control.Monad
+> import Control.Monad.Writer (Writer, mapWriter, runWriter, tell)
 
 > type Name = Int