diff --git a/Data/Foldable1.hs b/Data/Foldable1.hs
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--- /dev/null
+++ b/Data/Foldable1.hs
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+module Data.Foldable1 where
+
+import Prelude hiding (head, tail, init, last, scanl1, scanr1)
+import Control.Applicative.Backwards
+import Data.Foldable (foldl', foldlM)
+import Data.Functor.Compose
+import Data.Functor.Identity
+import Data.Functor.Product
+import Data.Functor.Reverse
+import Data.Functor.Sum
+import Data.List.NonEmpty (NonEmpty (..), head, last, scanl1, scanr1, uncons)
+import qualified Data.List.NonEmpty as NE
+import Data.Semigroup (Semigroup (..), Dual (..), Max (..), Min (..))
+import Util ((&))
+
+class Foldable f => Foldable1 f where
+    {-# MINIMAL foldMap1 | toNonEmpty #-}
+
+    fold1 :: Semigroup a => f a -> a
+    fold1 = foldMap1 id
+
+    foldMap1 :: Semigroup b => (a -> b) -> f a -> b
+    foldMap1 f = sconcat . fmap f . toNonEmpty
+
+    foldr1, foldl1, foldr1', foldl1' :: (a -> a -> a) -> f a -> a
+    foldr1 f = head . scanr1 f . toNonEmpty
+    foldl1 f = last . scanl1 f . toNonEmpty
+    foldl1' f = toNonEmpty & \ (a:|as) -> foldl' f a as
+    foldr1' f = toNonEmpty & go
+      where go = uncons & \ case (a, Nothing) -> a
+                                 (a, Just as) -> a `f` go as
+
+    toNonEmpty :: f a -> NonEmpty a
+    toNonEmpty = foldMap1 pure
+
+    maximum, minimum :: Ord a => f a -> a
+    maximum = getMax . foldMap1 Max
+    minimum = getMin . foldMap1 Min
+
+intercalate :: (Foldable1 f, Semigroup a) => a -> f a -> a
+intercalate a = sconcat . NE.intersperse a . toNonEmpty
+
+foldrM1, foldlM1 :: (Foldable1 f, Monad m) => (a -> a -> m a) -> f a -> m a
+foldrM1 f = go . toNonEmpty
+  where go (a:|[])   = pure a
+        go (a:|b:bs) = f a =<< go (b:|bs)
+foldlM1 f = toNonEmpty & \ (a:|as) -> foldlM f a as
+
+instance Foldable1 Identity where
+    foldMap1 f = f . runIdentity
+
+instance Foldable1 NonEmpty where
+    toNonEmpty = id
+
+instance Foldable1 ((,) a) where
+    foldMap1 f = f . snd
+
+deriving instance (Foldable1 f) => Foldable1 (Backwards f)
+
+instance (Foldable1 f) => Foldable1 (Reverse f) where
+    foldMap1 f (Reverse as) = getDual $ foldMap1 (Dual . f) as
+
+instance (Foldable1 f, Foldable1 g) => Foldable1 (Compose f g) where
+    foldMap1 f = (foldMap1 . foldMap1) f . getCompose
+
+instance (Foldable1 f, Foldable1 g) => Foldable1 (Product f g) where
+    foldMap1 f (Pair as bs) = foldMap1 f as <> foldMap1 f bs
+
+instance (Foldable1 f, Foldable1 g) => Foldable1 (Sum f g) where
+    foldMap1 f (InL as) = foldMap1 f as
+    foldMap1 f (InR bs) = foldMap1 f bs
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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--- /dev/null
+++ b/README.md
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+# foldable1
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/foldable1.cabal b/foldable1.cabal
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--- /dev/null
+++ b/foldable1.cabal
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+name:                foldable1
+version:             0.1.0.0
+synopsis:            Foldable types with at least 1 element
+-- 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
+  exposed-modules:     Data.Foldable1
+  build-depends:       base >= 4.7 && < 5
+                     , transformers >= 0.3 && < 0.6
+                     , util
+  default-language:    Haskell2010
+  default-extensions:  UnicodeSyntax
+                     , LambdaCase
+                     , EmptyCase
+                     , InstanceSigs
+                     , PartialTypeSignatures
+                     , PolyKinds
+                     , ConstraintKinds
+                     , FlexibleContexts
+                     , FlexibleInstances
+                     , MonadComprehensions
+                     , StandaloneDeriving
+                     , GeneralizedNewtypeDeriving
+                     , DeriveFunctor, DeriveFoldable, DeriveTraversable
+  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/foldable1.hs