implement Network.RemoteData

1 files changed, 33 insertions, 0 deletions

diff --git a/lore/Network/RemoteData.hs b/lore/Network/RemoteData.hs
new file mode 100644
index 0000000..a2c58a7
--- /dev/null
+++ b/lore/Network/RemoteData.hs
@@ -0,0 +1,33 @@
+-- | A port of Kris Jenkins' RemoteData Elm module
+-- <https://github.com/krisajenkins/remotedata>.
+--
+module Network.RemoteData where
+
+data RemoteData a b
+    = NotAsked
+    | Loading
+    | Failure a
+    | Success b
+
+-- TODO figure out Http.Error
+-- type WebData a = RemoteData Http.Error a
+
+instance Functor (RemoteData a) where
+    fmap _ NotAsked = NotAsked
+    fmap _ Loading = Loading
+    fmap _ (Failure a) = Failure a
+    fmap f (Success a) = Success (f a)
+
+instance Applicative (RemoteData e) where
+    pure = Success
+    NotAsked <*> _ = NotAsked
+    Loading <*> _ = Loading
+    Failure a <*> _ = Failure a
+    Success a <*> b = fmap a b
+
+instance Show (RemoteData a b)
+instance Eq (RemoteData a b)
+
+fromEither :: Either a b -> RemoteData a b
+fromEither (Left a) = Failure a
+fromEither (Right a) = Success a