Merge pull request #6 from purescript/cat-maybes

Add catMaybes

Author: paf31

README.md

@@ -25,6 +25,8 @@
 
     append :: forall a. [a] -> [a] -> [a]
 
+    catMaybes :: forall a. [Maybe a] -> [a]
+
     concat :: forall a. [[a]] -> [a]
 
     concatMap :: forall a b. (a -> [b]) -> [a] -> [b]

src/Data/Array.purs

@@ -9,6 +9,7 @@ module Data.Array
   , null
   , map
   , mapMaybe
+  , catMaybes
   , length
   , findIndex
   , findLastIndex
@@ -218,6 +219,9 @@ foreign import map
 mapMaybe :: forall a b. (a -> Maybe b) -> [a] -> [b]
 mapMaybe f = concatMap (maybe [] singleton <<< f)
 
+catMaybes :: forall a. [Maybe a] -> [a]
+catMaybes = concatMap (maybe [] singleton)
+
 foreign import filter
   "function filter (f) {\
   \  return function (arr) {\