Add remaining haskell book exercises

1 files changed, 30 insertions, 0 deletions

diff --git a/Haskell-book/15/semigroup/src/Bool.hs b/Haskell-book/15/semigroup/src/Bool.hs
new file mode 100644
index 0000000..2efdd34
--- /dev/null
+++ b/Haskell-book/15/semigroup/src/Bool.hs
@@ -0,0 +1,30 @@
+module Bool where
+
+import Data.Semigroup
+import Test.QuickCheck
+
+newtype BoolConj = BoolConj Bool deriving (Eq, Show)
+
+instance Semigroup BoolConj where
+    (BoolConj True) <> (BoolConj True) = BoolConj True
+    _ <> _ = BoolConj False
+
+instance Monoid BoolConj where
+    mempty = BoolConj True
+    mappend = (<>)
+
+instance Arbitrary BoolConj where
+    arbitrary = fmap BoolConj arbitrary
+
+newtype BoolDisj = BoolDisj Bool deriving (Eq, Show)
+
+instance Semigroup BoolDisj where
+    (BoolDisj False) <> (BoolDisj False) = BoolDisj False
+    _ <> _ = BoolDisj True
+
+instance Monoid BoolDisj where
+    mempty = BoolDisj False
+    mappend = (<>)
+
+instance Arbitrary BoolDisj where
+    arbitrary = fmap BoolDisj arbitrary