From ccb50d835ec5ae2e5233c92838755564c7a19e59 Mon Sep 17 00:00:00 2001
From: David Koontz <david@koontzfamily.org>
Date: Tue, 24 Jan 2017 17:06:28 -0700
Subject: [PATCH] Implement `Iso` mapping for Nullable to Maybe

---
 bower.json             | 3 ++-
 src/Data/Nullable.purs | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/bower.json b/bower.json
index e81ee7f..e802f09 100644
--- a/bower.json
+++ b/bower.json
@@ -15,7 +15,8 @@
   ],
   "dependencies": {
     "purescript-maybe": "^2.0.0",
-    "purescript-functions": "^2.0.0"
+    "purescript-functions": "^2.0.0",
+    "purescript-isomorphisms": "^3.0.0"
   },
   "repository": {
     "type": "git",
diff --git a/src/Data/Nullable.purs b/src/Data/Nullable.purs
index a082a13..d9578df 100644
--- a/src/Data/Nullable.purs
+++ b/src/Data/Nullable.purs
@@ -3,6 +3,7 @@
 
 module Data.Nullable
   ( Nullable
+  , isoNullableMaybe
   , toMaybe
   , toNullable
   ) where
@@ -11,6 +12,7 @@ import Prelude
 
 import Data.Function (on)
 import Data.Function.Uncurried (Fn3, runFn3)
+import Data.Iso (Iso(Iso))
 import Data.Maybe (Maybe(..), maybe)
 
 -- | A nullable type.
@@ -35,6 +37,9 @@ toNullable = maybe null notNull
 toMaybe :: forall a. Nullable a -> Maybe a
 toMaybe n = runFn3 nullable n Nothing Just
 
+isoNullableMaybe :: forall a. Iso (Nullable a) (Maybe a)
+isoNullableMaybe = Iso toMaybe toNullable
+
 instance showNullable :: Show a => Show (Nullable a) where
   show = maybe "null" show <<< toMaybe