Merge pull request #29 from matthewleon/Unfoldable1

Unfoldable1 support

Author: garyb

bower.json

@@ -18,7 +18,8 @@
   ],
   "dependencies": {
     "purescript-foldable-traversable": "^3.4.0",
-    "purescript-prelude": "^3.0.0"
+    "purescript-prelude": "^3.0.0",
+    "purescript-unfoldable": "^3.2.0"
   },
   "devDependencies": {
     "purescript-assert": "^3.0.0",

src/Data/NonEmpty.purs

@@ -27,6 +27,9 @@ import Data.Ord (class Ord1, compare1)
 import Data.Semigroup.Foldable as F1
 import Data.Traversable (class Traversable, traverse, sequence)
 import Data.TraversableWithIndex (class TraversableWithIndex, traverseWithIndex)
+import Data.Tuple (uncurry)
+import Data.Unfoldable (class Unfoldable, unfoldr)
+import Data.Unfoldable1 (class Unfoldable1)
 
 -- | A non-empty container of elements of type a.
 -- |
@@ -122,3 +125,6 @@ instance traversableWithIndexNonEmpty
 instance foldable1NonEmpty :: Foldable f => F1.Foldable1 (NonEmpty f) where
   fold1 = foldMap1 id
   foldMap1 f (a :| fa) = foldl (\s a1 -> s <> f a1) (f a) fa
+
+instance unfoldable1NonEmpty :: Unfoldable f => Unfoldable1 (NonEmpty f) where
+  unfoldr1 f b = uncurry (:|) $ unfoldr (map f) <$> f b

test/Main.purs

@@ -6,6 +6,7 @@ import Control.Monad.Eff (Eff)
 import Data.Foldable (fold, foldl)
 import Data.Maybe (Maybe(..))
 import Data.NonEmpty (NonEmpty(), (:|), fold1, foldl1, oneOf, head, tail, singleton)
+import Data.Unfoldable1 as U1
 import Test.Assert (ASSERT, assert)
 
 type AtLeastTwo f a = NonEmpty (NonEmpty f) a
@@ -23,3 +24,4 @@ main = do
   assert $ fold ("Hello" :| [" ", "World"]) == "Hello World"
   assert $ oneOf (0 :| Nothing) == oneOf (0 :| Just 1)
   assert $ second (1 :| 2 :| [3, 4]) == 2
+  assert $ U1.range 0 9 == (0 :| [1, 2, 3, 4, 5, 6, 7, 8, 9])