From d5c51281158d0b29408b6aae5035c6b6ee700b5b Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 9 Feb 2020 23:06:12 -0500
Subject: [PATCH] Use isJust instead of reimplementing it

---
 src/ShellCheck/Checks/ShellSupport.hs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/ShellCheck/Checks/ShellSupport.hs b/src/ShellCheck/Checks/ShellSupport.hs
index 924b002..83d7887 100644
--- a/src/ShellCheck/Checks/ShellSupport.hs
+++ b/src/ShellCheck/Checks/ShellSupport.hs
@@ -456,11 +456,10 @@ checkEchoSed = ForShell [Bash, Ksh] f
 
     -- This should have used backreferences, but TDFA doesn't support them
     sedRe = mkRegex "^s(.)([^\n]*)g?$"
-    isSimpleSed s = fromMaybe False $ do
+    isSimpleSed s = isJust $ do
         [h:_,rest] <- matchRegex sedRe s
         let delimiters = filter (== h) rest
         guard $ length delimiters == 2
-        return True
     checkIn id s =
         when (isSimpleSed s) $
             style id 2001 "See if you can use ${variable//search/replace} instead."