From 90cb4fcd88ab66a614ecda0aec054b3c4a3e7316 Mon Sep 17 00:00:00 2001
From: fr33domlover <fr33domlover@riseup.net>
Date: Sat, 29 Jun 2019 22:39:42 +0000
Subject: [PATCH] Data.Aeson.Encode.Pretty.ToEncoding: Use
 encodePrettyToTextBuilder as base

aeson-pretty implements by formatting using a text Builder, and the ByteString
is encoded from that. So instead of decoding the ByteString to produce Text or
Builder, use the Builder as the starting point, to match how aeson-pretty works
and save computation and weird backwards-decoding stuff.
---
 src/Data/Aeson/Encode/Pretty/ToEncoding.hs | 24 +++++++++++++---------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/Data/Aeson/Encode/Pretty/ToEncoding.hs b/src/Data/Aeson/Encode/Pretty/ToEncoding.hs
index bd9f1e6..953b8e8 100644
--- a/src/Data/Aeson/Encode/Pretty/ToEncoding.hs
+++ b/src/Data/Aeson/Encode/Pretty/ToEncoding.hs
@@ -24,21 +24,25 @@ where
 
 import Data.Aeson (ToJSON, Value, encode, decode)
 import Data.ByteString.Lazy (ByteString)
-import Data.Maybe (fromJust)
 import Data.Text.Lazy (Text)
-import Data.Text.Lazy.Builder (Builder, fromLazyText)
-import Data.Text.Lazy.Encoding (decodeUtf8)
+import Data.Text.Lazy.Builder (Builder, toLazyText)
+import Data.Text.Lazy.Encoding (encodeUtf8)
 
-import qualified Data.Aeson.Encode.Pretty as P (encodePretty)
+import qualified Data.Aeson.Encode.Pretty as P
 
 encodePretty :: ToJSON a => a -> ByteString
-encodePretty = P.encodePretty . fromJust . decodeValue . encode
-    where
-    decodeValue :: ByteString -> Maybe Value
-    decodeValue = decode
+encodePretty = encodeUtf8 . encodePrettyToLazyText
 
 encodePrettyToLazyText :: ToJSON a => a -> Text
-encodePrettyToLazyText = decodeUtf8 . encodePretty
+encodePrettyToLazyText = toLazyText . encodePrettyToTextBuilder
 
 encodePrettyToTextBuilder :: ToJSON a => a -> Builder
-encodePrettyToTextBuilder = fromLazyText . encodePrettyToLazyText
+encodePrettyToTextBuilder =
+    P.encodePrettyToTextBuilder . decodeValue . encode
+    where
+    decodeValue :: ByteString -> Value
+    decodeValue b =
+        case decode b of
+            Nothing ->
+                error "encodePretty: Failed to decode encoded JSON into Value"
+            Just v -> v