diff --git a/Enum.cabal b/Enum.cabal
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--- /dev/null
+++ b/Enum.cabal
@@ -0,0 +1,38 @@
+name:                Enum
+version:             0.1.0.0
+synopsis:            Non-crashing `Enum` operations
+-- description:
+license:             BSD3
+license-file:        LICENSE
+author:              M Farkas-Dyck
+maintainer:          strake888@gmail.com
+copyright:           2018 M Farkas-Dyck
+-- category:            
+build-type:          Simple
+extra-source-files:  README.md
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      .
+  exposed-modules:     Util.Enum
+  build-depends:       base >= 4.7 && < 5
+  default-language:    Haskell2010
+  default-extensions:  UnicodeSyntax
+                     , LambdaCase
+                     , EmptyCase
+                     , PartialTypeSignatures
+                     , ScopedTypeVariables
+                     , FlexibleContexts
+                     , FlexibleInstances
+                     , DeriveFunctor, DeriveFoldable
+  ghc-options:         -Wall -Wcompat -Wredundant-constraints -Wno-name-shadowing
+                       -Wincomplete-record-updates -Wincomplete-uni-patterns
+                       -Werror=incomplete-patterns
+                       -Werror=incomplete-uni-patterns
+                       -Werror=incomplete-record-updates
+                       -Werror=missing-fields
+                       -Werror=missing-methods
+
+source-repository head
+  type:     git
+  location: https://github.com/strake/Enum.hs
diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
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+Copyright M Farkas-Dyck © 2018
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of M Farkas-Dyck nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
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+++ b/README.md
@@ -0,0 +1,1 @@
+# Enum
diff --git a/Setup.hs b/Setup.hs
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+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/Util/Enum.hs b/Util/Enum.hs
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--- /dev/null
+++ b/Util/Enum.hs
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+module Util.Enum (toEnumMay, fromEnum, predMay, succMay) where
+
+import Prelude hiding (filter, fromEnum, head, tail)
+import qualified Prelude
+import Control.Applicative
+import Control.Monad
+import Control.Exception
+import Data.Bool (bool)
+import Data.Maybe (fromMaybe)
+import Data.Semigroup (Semigroup (..), stimes)
+import System.IO.Unsafe
+
+toEnumMay :: Enum a => Integer -> Maybe a
+toEnumMay n = opMay (toEnum . fromIntegral) n <|> toEnumSafe n
+
+toEnumSafe :: Enum a => Integer -> Maybe a
+toEnumSafe n = stimes (abs n) (EndoM $ bool succMay predMay $ n < 0) `endoM` toEnum 0
+
+fromEnum :: Enum a => a -> Integer
+fromEnum = fromMaybe <$> fromEnumSafe <*> opMay (fromIntegral . Prelude.fromEnum)
+
+fromEnumSafe :: Enum a => a -> Integer
+fromEnumSafe a = head $ f `mapMaybe` let go n = n :. negate n :. go (n+1) in 0 :. go 1
+  where f n = n <$ (guard . (== 0) =<< opMay Prelude.fromEnum =<<
+                    stimes (abs n) (EndoM $ bool succMay predMay $ n < 0) `endoM` a)
+
+predMay, succMay :: Enum a => a -> Maybe a
+predMay = opMay pred
+succMay = opMay succ
+
+opMay :: (a -> b) -> a -> Maybe b
+opMay f a = unsafePerformIO $ (Just <$> evaluate (f a)) `catches` handlers Nothing
+
+handlers :: a -> [Handler a]
+handlers a = [Handler $ \ (_ :: ArithException) -> pure a,
+              Handler $ \ (_ :: ArrayException) -> pure a,
+              Handler $ \ (_ :: AssertionFailed) -> pure a,
+              Handler $ \ (_ :: NonTermination) -> pure a,
+              Handler $ \ (_ :: NoMethodError) -> pure a,
+              Handler $ \ (_ :: PatternMatchFail) -> pure a,
+              Handler $ \ (_ :: RecConError) -> pure a,
+              Handler $ \ (_ :: RecSelError) -> pure a,
+              Handler $ \ (_ :: RecUpdError) -> pure a,
+              Handler $ \ (_ :: ErrorCall) -> pure a]
+
+newtype EndoM m a = EndoM { endoM :: a -> m a }
+instance Monad m => Semigroup (EndoM m a) where EndoM f <> EndoM g = EndoM (f >=> g)
+instance Monad m => Monoid (EndoM m a) where
+    mappend = (<>)
+    mempty = EndoM pure
+
+infixr 5 :.
+data Stream a = (:.) { head :: a, tail :: Stream a }
+  deriving (Functor, Foldable)
+
+instance Applicative Stream where
+    pure a = a :. pure a
+    f :. fs <*> x :. xs = f x :. (fs <*> xs)
+
+instance Monad Stream where
+    xs >>= f = join (f <$> xs) where join (a :. as) = head a :. join (tail <$> as)
+
+mapMaybe :: (a -> Maybe b) -> Stream a -> Stream b
+mapMaybe f (a :. as) = maybe id (:.) (f a) $ mapMaybe f as