diff --git a/LICENSE b/LICENSE
index 58b0299..311379c 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,20 +1,26 @@
-The MIT License (MIT)
+Copyright 2018 PureScript
 
-Copyright (c) 2014 PureScript
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
 
-Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (the "Software"), to deal in
-the Software without restriction, including without limitation the rights to
-use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
-the Software, and to permit persons to whom the Software is furnished to do so,
-subject to the following conditions:
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
 
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
+2. 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.
 
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+3. Neither the name of the copyright holder nor the names of its 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 HOLDER 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/bower.json b/bower.json
index 8222ab7..a50b3bf 100644
--- a/bower.json
+++ b/bower.json
@@ -1,8 +1,7 @@
 {
   "name": "purescript-unfoldable",
   "homepage": "https://github.com/purescript/purescript-unfoldable",
-  "description": "Unfoldable Functors",
-  "license": "MIT",
+  "license": "BSD-3-Clause",
   "repository": {
     "type": "git",
     "url": "git://github.com/purescript/purescript-unfoldable.git"
@@ -17,11 +16,14 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-partial": "^1.2.0",
-    "purescript-tuples": "^4.0.0"
+    "purescript-foldable-traversable": "^4.0.0",
+    "purescript-maybe": "^4.0.0",
+    "purescript-partial": "^2.0.0",
+    "purescript-prelude": "^4.0.0",
+    "purescript-tuples": "^5.0.0"
   },
   "devDependencies": {
-    "purescript-assert": "^3.0.0",
-    "purescript-console": "^3.0.0"
+    "purescript-assert": "^4.0.0",
+    "purescript-console": "^4.0.0"
   }
 }
diff --git a/package.json b/package.json
index 132cefc..6615039 100644
--- a/package.json
+++ b/package.json
@@ -6,9 +6,9 @@
     "test": "pulp test"
   },
   "devDependencies": {
-    "eslint": "^3.17.1",
-    "pulp": "^10.0.4",
-    "purescript-psa": "^0.5.0-rc.1",
-    "rimraf": "^2.6.1"
+    "eslint": "^4.19.1",
+    "pulp": "^12.2.0",
+    "purescript-psa": "^0.6.0",
+    "rimraf": "^2.6.2"
   }
 }
diff --git a/src/Data/Unfoldable.purs b/src/Data/Unfoldable.purs
index 3ed0ad0..e4d193e 100644
--- a/src/Data/Unfoldable.purs
+++ b/src/Data/Unfoldable.purs
@@ -9,9 +9,8 @@ module Data.Unfoldable
   , replicate
   , replicateA
   , none
-  , singleton
-  , range
   , fromMaybe
+  , module Data.Unfoldable1
   ) where
 
 import Prelude
@@ -19,7 +18,7 @@ import Prelude
 import Data.Maybe (Maybe(..), isNothing, fromJust)
 import Data.Traversable (class Traversable, sequence)
 import Data.Tuple (Tuple(..), fst, snd)
-
+import Data.Unfoldable1 (class Unfoldable1, unfoldr1, singleton, range, replicate1, replicate1A)
 import Partial.Unsafe (unsafePartial)
 
 -- | This class identifies data structures which can be _unfolded_.
@@ -29,7 +28,7 @@ import Partial.Unsafe (unsafePartial)
 -- | - If `f b` is `Nothing`, then `unfoldr f b` should be empty.
 -- | - If `f b` is `Just (Tuple a b1)`, then `unfoldr f b` should consist of `a`
 -- |   appended to the result of `unfoldr f b1`.
-class Unfoldable t where
+class Unfoldable1 t <= Unfoldable t where
   unfoldr :: forall a b. (b -> Maybe (Tuple a b)) -> b -> t a
 
 instance unfoldableArray :: Unfoldable Array where
@@ -48,9 +47,9 @@ foreign import unfoldrArrayImpl
 -- | Replicate a value some natural number of times.
 -- | For example:
 -- |
--- | ~~~ purescript
+-- | ``` purescript
 -- | replicate 2 "foo" == ["foo", "foo"] :: Array String
--- | ~~~
+-- | ```
 replicate :: forall f a. Unfoldable f => Int -> a -> f a
 replicate n v = unfoldr step n
   where
@@ -73,26 +72,12 @@ replicateA n m = sequence (replicate n m)
 -- | The container with no elements - unfolded with zero iterations.
 -- | For example:
 -- |
--- | ~~~ purescript
+-- | ``` purescript
 -- | none == [] :: forall a. Array a
--- | ~~~
+-- | ```
 none :: forall f a. Unfoldable f => f a
 none = unfoldr (const Nothing) unit
 
--- | Contain a single value.
--- | For example:
--- |
--- | ~~~ purescript
--- | singleton "foo" == ["foo"] :: Array String
--- | ~~~
-singleton :: forall f a. Unfoldable f => a -> f a
-singleton = replicate 1
-
--- | Create an Unfoldable containing a range of values, with both endpoints.
-range :: forall f. Unfoldable f => Int -> Int -> f Int
-range start end =
-  unfoldr (\i -> if i <= end then Just (Tuple i $ i + 1) else Nothing) start
-
 -- | Convert a Maybe to any Unfoldable like lists and arrays.
 fromMaybe :: forall f a. Unfoldable f => Maybe a -> f a
 fromMaybe = unfoldr (\b -> flip Tuple Nothing <$> b)
diff --git a/src/Data/Unfoldable1.js b/src/Data/Unfoldable1.js
new file mode 100644
index 0000000..d794fdf
--- /dev/null
+++ b/src/Data/Unfoldable1.js
@@ -0,0 +1,23 @@
+"use strict";
+
+exports.unfoldr1ArrayImpl = function (isNothing) {
+  return function (fromJust) {
+    return function (fst) {
+      return function (snd) {
+        return function (f) {
+          return function (b) {
+            var result = [];
+            var value = b;
+            while (true) { // eslint-disable-line no-constant-condition
+              var tuple = f(value);
+              result.push(fst(tuple));
+              var maybe = snd(tuple);
+              if (isNothing(maybe)) return result;
+              value = fromJust(maybe);
+            }
+          };
+        };
+      };
+    };
+  };
+};
diff --git a/src/Data/Unfoldable1.purs b/src/Data/Unfoldable1.purs
index c8f51e5..a2f0314 100644
--- a/src/Data/Unfoldable1.purs
+++ b/src/Data/Unfoldable1.purs
@@ -8,9 +8,10 @@ module Data.Unfoldable1
 
 import Prelude
 
-import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe(..), fromJust, isNothing)
 import Data.Semigroup.Traversable (class Traversable1, sequence1)
-import Data.Tuple (Tuple(..))
+import Data.Tuple (Tuple(..), fst, snd)
+import Partial.Unsafe (unsafePartial)
 
 -- | This class identifies non-empty data structures which can be _unfolded_.
 -- |
@@ -20,6 +21,19 @@ import Data.Tuple (Tuple(..))
 class Unfoldable1 t where
   unfoldr1 :: forall a b. (b -> Tuple a (Maybe b)) -> b -> t a
 
+instance unfoldable1Array :: Unfoldable1 Array where
+  unfoldr1 = unfoldr1ArrayImpl isNothing (unsafePartial fromJust) fst snd
+
+foreign import unfoldr1ArrayImpl
+  :: forall a b
+   . (forall x. Maybe x -> Boolean)
+  -> (forall x. Maybe x -> x)
+  -> (forall x y. Tuple x y -> x)
+  -> (forall x y. Tuple x y -> y)
+  -> (b -> Tuple a (Maybe b))
+  -> b
+  -> Array a
+
 -- | Replicate a value `n` times. At least one value will be produced, so values
 -- | `n < 1` less than one will be ignored.
 -- |
diff --git a/test/Main.purs b/test/Main.purs
index ae769e8..6ebef5b 100644
--- a/test/Main.purs
+++ b/test/Main.purs
@@ -2,17 +2,18 @@ module Test.Main where
 
 import Prelude
 
-import Control.Monad.Eff (Eff)
-import Control.Monad.Eff.Console (CONSOLE, log, logShow)
+import Data.Eq (class Eq1)
 import Data.Maybe (Maybe(..))
 import Data.Tuple (Tuple(..), uncurry)
 import Data.Unfoldable as U
 import Data.Unfoldable1 as U1
-import Test.Assert (ASSERT, assert)
+import Effect (Effect)
+import Effect.Console (log, logShow)
+import Test.Assert (assert)
 
 data NonEmpty f a = NonEmpty a (f a)
 
-derive instance eqNonEmpty :: (Eq (f a), Eq a) => Eq (NonEmpty f a)
+derive instance eqNonEmpty :: (Eq1 f, Eq a) => Eq (NonEmpty f a)
 
 instance unfoldable1NonEmpty :: U.Unfoldable f => U1.Unfoldable1 (NonEmpty f) where
   unfoldr1 f = uncurry NonEmpty <<< map (U.unfoldr $ map f) <<< f
@@ -28,7 +29,7 @@ collatz = U.unfoldr step
         then n / 2
         else n * 3 + 1
 
-main :: Eff (assert :: ASSERT, console :: CONSOLE) Unit
+main :: Effect Unit
 main = do
   log "Collatz 1000"
   logShow $ collatz 1000
@@ -52,12 +53,10 @@ main = do
     [2,1,1],[2,1,2], [2,2,1],[2,2,2]
   ]
 
-  log "Test U.range"
-  assert $ U.range 1 0 == []
-  assert $ U.range 0 0 == [0]
-  assert $ U.range 0 2 == [0, 1, 2]
-
-  log "Test U1.range"
+  log "Test range"
+  assert $ U1.range 1 0 == [1, 0]
+  assert $ U1.range 0 0 == [0]
+  assert $ U1.range 0 2 == [0, 1, 2]
   assert $ U1.range 1 0 == NonEmpty 1 [0]
   assert $ U1.range 0 0 == NonEmpty 0 []
   assert $ U1.range 0 2 == NonEmpty 0 [1, 2]