fix: nats support GHC 7

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Bodigrim · Jan 16, 2023 · dfd5085 · dfd5085
1 parent 0b354e8
commit dfd5085
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/test/Test.hs b/test/Test.hs
@@ -63,7 +63,11 @@ evalWriterT :: (Monad m, Monoid w) => CpsW.WriterT w m a -> m a
 evalWriterT = fmap fst . CpsW.runWriterT
 #endif
 
+#if MIN_VERSION_base(4,8,0)
 nats = pure 0 `mplus` ((1 +) <$> nats)
+#else
+nats = return 0 `mplus` liftM (1 +) nats
+#endif
 
 odds = return 1 `mplus` liftM (2+) odds