From f2805f0459bfed319850c53124a3b4ba2cc80398 Mon Sep 17 00:00:00 2001
From: Anupam Jain <ajnsit@gmail.com>
Date: Thu, 14 Mar 2019 10:29:38 +0530
Subject: [PATCH] Add encode/decode instances for `Identity a`

---
 bower.json                          | 3 ++-
 src/Data/Argonaut/Decode/Class.purs | 4 ++++
 src/Data/Argonaut/Encode/Class.purs | 4 ++++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/bower.json b/bower.json
index fa60e6b..3119c4b 100644
--- a/bower.json
+++ b/bower.json
@@ -29,7 +29,8 @@
     "purescript-foreign-object": "^2.0.0",
     "purescript-record": "^2.0.0",
     "purescript-nonempty": "^5.0.0",
-    "purescript-arrays": "^5.1.0"
+    "purescript-arrays": "^5.1.0",
+    "purescript-identity": "^4.1.0"
   },
   "devDependencies": {
     "purescript-assert": "^4.1.0",
diff --git a/src/Data/Argonaut/Decode/Class.purs b/src/Data/Argonaut/Decode/Class.purs
index 8f5a5a1..f476bdd 100644
--- a/src/Data/Argonaut/Decode/Class.purs
+++ b/src/Data/Argonaut/Decode/Class.purs
@@ -6,6 +6,7 @@ import Data.Argonaut.Core (Json, isNull, caseJsonNull, caseJsonBoolean, caseJson
 import Data.Array as Arr
 import Data.Bifunctor (lmap, rmap)
 import Data.Either (Either(..), note)
+import Data.Identity (Identity(..))
 import Data.Int (fromNumber)
 import Data.List (List(..), (:), fromFoldable)
 import Data.List as L
@@ -27,6 +28,9 @@ import Type.Data.RowList (RLProxy(..))
 class DecodeJson a where
   decodeJson :: Json -> Either String a
 
+instance decodeIdentity :: DecodeJson a => DecodeJson (Identity a) where
+  decodeJson j = Identity <$> decodeJson j
+
 instance decodeJsonMaybe :: DecodeJson a => DecodeJson (Maybe a) where
   decodeJson j
     | isNull j = pure Nothing
diff --git a/src/Data/Argonaut/Encode/Class.purs b/src/Data/Argonaut/Encode/Class.purs
index 18ae069..8297fe2 100644
--- a/src/Data/Argonaut/Encode/Class.purs
+++ b/src/Data/Argonaut/Encode/Class.purs
@@ -5,6 +5,7 @@ import Prelude
 import Data.Argonaut.Core (Json, fromArray, fromBoolean, fromNumber, fromObject, fromString, jsonNull)
 import Data.Array as Arr
 import Data.Either (Either, either)
+import Data.Identity (Identity(..))
 import Data.Int (toNumber)
 import Data.List (List(..), (:), toUnfoldable)
 import Data.List as L
@@ -26,6 +27,9 @@ import Type.Data.RowList (RLProxy(..))
 class EncodeJson a where
   encodeJson :: a -> Json
 
+instance encodeIdentity :: EncodeJson a => EncodeJson (Identity a) where
+  encodeJson (Identity a) = encodeJson a
+
 instance encodeJsonMaybe :: EncodeJson a => EncodeJson (Maybe a) where
   encodeJson Nothing  = jsonNull
   encodeJson (Just a) = encodeJson a