From 5e03c2793606919d805995f8d93ac25da1763f54 Mon Sep 17 00:00:00 2001
From: mhmdanas <32234660+mhmdanas@users.noreply.github.com>
Date: Fri, 15 Apr 2022 21:55:47 +0300
Subject: [PATCH] Make `RegexFlags` a `newtype`

---
 CHANGELOG.md                     |  1 +
 src/Data/String/Regex/Flags.purs | 14 +++++---------
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 02cb63e..28863e1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ Bugfixes:
 
 Other improvements:
 - Surround code with backticks in documentation (#148)
+- Make `RegexFlags` a `newtype` and a `Newtype` instance for it(#159 by @mhmdanas)
 
 ## [v5.0.0](https://github.com/purescript/purescript-strings/releases/tag/v5.0.0) - 2021-02-26
 
diff --git a/src/Data/String/Regex/Flags.purs b/src/Data/String/Regex/Flags.purs
index dc7a0c7..49228f3 100644
--- a/src/Data/String/Regex/Flags.purs
+++ b/src/Data/String/Regex/Flags.purs
@@ -3,6 +3,7 @@ module Data.String.Regex.Flags where
 import Prelude
 
 import Control.MonadPlus (guard)
+import Data.Newtype (class Newtype)
 import Data.String (joinWith)
 
 type RegexFlagsRec =
@@ -15,7 +16,9 @@ type RegexFlagsRec =
   }
 
 -- | Flags that control matching.
-data RegexFlags = RegexFlags RegexFlagsRec
+newtype RegexFlags = RegexFlags RegexFlagsRec
+
+derive instance newtypeRegexFlags :: Newtype RegexFlags _
 
 -- | All flags set to false.
 noFlags :: RegexFlags
@@ -107,14 +110,7 @@ instance semigroupRegexFlags :: Semigroup RegexFlags where
 instance monoidRegexFlags :: Monoid RegexFlags where
   mempty = noFlags
 
-instance eqRegexFlags :: Eq RegexFlags where
-  eq (RegexFlags x) (RegexFlags y)
-    = x.global == y.global
-    && x.ignoreCase == y.ignoreCase
-    && x.multiline == y.multiline
-    && x.dotAll == y.dotAll
-    && x.sticky == y.sticky
-    && x.unicode == y.unicode
+derive newtype instance eqRegexFlags :: Eq RegexFlags
 
 instance showRegexFlags :: Show RegexFlags where
   show (RegexFlags flags) =