From 4856ec516f0733c8aef065166a417a358f12fe62 Mon Sep 17 00:00:00 2001
From: Rene Vergara <rene@vergara.network>
Date: Mon, 5 Feb 2024 15:18:01 -0600
Subject: [PATCH] Borsh serialization for HexString

---
 CHANGELOG.md          |  1 +
 README.md             |  5 ----
 hexstring.cabal       |  3 ++
 package.yaml          |  3 ++
 src/Data/HexString.hs | 64 +++++++++++++++++++++++++++----------------
 stack.yaml            |  6 ++++
 6 files changed, 53 insertions(+), 29 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3e74184..67385b0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - CHANGELOG.md
 - Stack integration
+- Borsh serialization for `HexString`
 
 ### Changed
 
diff --git a/README.md b/README.md
index 45afa52..5bdd5d1 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,4 @@
 haskell-hexstring
 =================
 
-[![Build Status](https://travis-ci.org/solatis/haskell-hexstring.png?branch=master)](https://travis-ci.org/solatis/haskell-hexstring)
-[![Coverage Status](https://coveralls.io/repos/solatis/haskell-hexstring/badge.svg?branch=master)](https://coveralls.io/r/solatis/haskell-hexstring?branch=master)
-[![MIT](http://b.repl.ca/v1/license-MIT-blue.png)](http://en.wikipedia.org/wiki/MIT_License)
-[![Haskell](http://b.repl.ca/v1/language-haskell-lightgrey.png)](http://haskell.org)
-
 Fast and safe representation of a hex string
diff --git a/hexstring.cabal b/hexstring.cabal
index 56b5d84..a675077 100644
--- a/hexstring.cabal
+++ b/hexstring.cabal
@@ -35,7 +35,10 @@ library
     , base >=4.7 && <5
     , base16-bytestring
     , binary
+    , borsh >=0.2
     , bytestring
+    , foreign-rust
+    , generics-sop
     , text
   default-language: Haskell2010
 
diff --git a/package.yaml b/package.yaml
index 680f2d2..bee7374 100644
--- a/package.yaml
+++ b/package.yaml
@@ -27,6 +27,9 @@ library:
     - bytestring
     - base16-bytestring
     - aeson
+    - generics-sop
+    - borsh >= 0.2
+    - foreign-rust
 
 tests:
   hextring-test:
diff --git a/src/Data/HexString.hs b/src/Data/HexString.hs
index 3caebcf..d66ae6c 100644
--- a/src/Data/HexString.hs
+++ b/src/Data/HexString.hs
@@ -1,36 +1,53 @@
-module Data.HexString ( HexString
-                      , hexString
-                      , fromBinary
-                      , toBinary
-                      , fromBytes
-                      , toBytes
-                      , toText ) where
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
 
-import           Control.Applicative    (pure)
+module Data.HexString
+  ( HexString
+  , hexString
+  , fromBinary
+  , toBinary
+  , fromBytes
+  , toBytes
+  , toText
+  ) where
 
-import           Data.Aeson
-import           Data.Word              (Word8)
+import Codec.Borsh
+import Control.Applicative (pure)
 
-import qualified Data.ByteString        as BS
+import Data.Aeson
+import Data.Word (Word8)
+
+import qualified Data.ByteString as BS
 import qualified Data.ByteString.Base16 as BS16 (decodeLenient, encode)
-import qualified Data.ByteString.Lazy   as BSL
+import qualified Data.ByteString.Lazy as BSL
 
-import qualified Data.Text              as T
-import qualified Data.Text.Encoding     as TE
+import Data.Structured
+import qualified Data.Text as T
+import qualified Data.Text.Encoding as TE
 
-import qualified Data.Binary            as B (Binary, decode, encode)
+import qualified Data.Binary as B (Binary, decode, encode)
+
+import qualified GHC.Generics as GHC
+import qualified Generics.SOP as SOP
 
 -- | Represents a Hex string. Guarantees that all characters it contains
 --   are valid hex characters.
 data HexString =
   HexString BS.ByteString
-  deriving ( Show, Eq, Ord )
+  deriving stock (Prelude.Show, GHC.Generic)
+  deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
+  deriving anyclass (Data.Structured.Show)
+  deriving (BorshSize, ToBorsh, FromBorsh) via AsStruct HexString
 
 instance FromJSON HexString where
   parseJSON = withText "HexString" $ pure . hexString . TE.encodeUtf8
 
 instance ToJSON HexString where
-  toJSON = String . toText
+  toJSON = Data.Aeson.String . toText
 
 -- | Smart constructor which validates that all the text are actually
 --   hexadecimal characters.
@@ -38,16 +55,15 @@ hexString :: BS.ByteString -> HexString
 hexString bs =
   let isValidHex :: Word8 -> Bool
       isValidHex c
-        | (48 <= c) && (c < 58)  = True
+        | (48 <= c) && (c < 58) = True
         | (97 <= c) && (c < 103) = True
-        | otherwise              = False
-
-  in if   BS.all isValidHex bs
-     then HexString bs
-     else error ("Not a valid hex string: " ++ show bs)
+        | otherwise = False
+   in if BS.all isValidHex bs
+        then HexString bs
+        else error ("Not a valid hex string: " ++ Prelude.show bs)
 
 -- | Converts a 'B.Binary' to a 'HexString' value
-fromBinary :: B.Binary a  => a -> HexString
+fromBinary :: B.Binary a => a -> HexString
 fromBinary = hexString . BS16.encode . BSL.toStrict . B.encode
 
 -- | Converts a 'HexString' to a 'B.Binary' value
diff --git a/stack.yaml b/stack.yaml
index 346aa08..7879a40 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -2,3 +2,9 @@ resolver: lts-21.22
 
 packages:
   - .
+
+extra-deps:
+  - git: https://github.com/well-typed/borsh.git
+    commit: d2fcfa159e0a844b1ec5e8ed3e232d4b380fa831
+  - git: https://git.vergara.tech/Vergara_Tech/haskell-foreign-rust.git
+    commit: 787c2e813eb3a5d16c375d4b37dfefbd2adcdf05