From 2a8170ba05c35b2a31950b2c380e0ad6247121c9 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:01:57 -0400
Subject: [PATCH 01/16] Use force instead of reimplementing it

---
 src/ShellCheck/AnalyzerLib.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 453d53d..086bd7c 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -178,7 +178,7 @@ makeCommentWithFix severity id code str fix =
         withFix = comment {
             tcFix = Just fix
         }
-    in withFix `deepseq` withFix
+    in force withFix
 
 makeParameters spec =
     let params = Parameters {

From b0dbc79f6973917aa51f1b9629e7a51a03162751 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:07:36 -0400
Subject: [PATCH 02/16] Remove unnecessary Maybe from isQuoteFreeElement

---
 src/ShellCheck/AnalyzerLib.hs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 086bd7c..0a4145a 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -293,15 +293,15 @@ isQuoteFree = isQuoteFreeNode False
 
 
 isQuoteFreeNode strict tree t =
-    (isQuoteFreeElement t == Just True) ||
+    isQuoteFreeElement t ||
         headOrDefault False (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t))
   where
     -- Is this node self-quoting in itself?
     isQuoteFreeElement t =
         case t of
-            T_Assignment {} -> return True
-            T_FdRedirect {} -> return True
-            _               -> Nothing
+            T_Assignment {} -> True
+            T_FdRedirect {} -> True
+            _               -> False
 
     -- Are any subnodes inherently self-quoting?
     isQuoteFreeContext t =

From b3c04ce3d0e0e95a0b3d9be9c58c18426d899d22 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:21:44 -0400
Subject: [PATCH 03/16] Implement findFirst in terms of foldr

---
 src/ShellCheck/AnalyzerLib.hs | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 0a4145a..4348438 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -388,14 +388,13 @@ parents params = getPath (parentMap params)
 -- Find the first match in a list where the predicate is Just True.
 -- Stops if it's Just False and ignores Nothing.
 findFirst :: (a -> Maybe Bool) -> [a] -> Maybe a
-findFirst p l =
-    case l of
-        [] -> Nothing
-        (x:xs) ->
-            case p x of
-                Just True  -> return x
-                Just False -> Nothing
-                Nothing    -> findFirst p xs
+findFirst p = foldr go Nothing
+  where
+    go x acc =
+      case p x of
+        Just True  -> return x
+        Just False -> Nothing
+        Nothing    -> acc
 
 -- Check whether a word is entirely output from a single command
 tokenIsJustCommandOutput t = case t of

From 14ee462ccd572c14ca292b47330e87c9307e0a7c Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:27:11 -0400
Subject: [PATCH 04/16] Use execState instead of reimplementing it

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

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 4348438..8f168dc 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -409,8 +409,7 @@ tokenIsJustCommandOutput t = case t of
 
 -- TODO: Replace this with a proper Control Flow Graph
 getVariableFlow params t =
-    let (_, stack) = runState (doStackAnalysis startScope endScope t) []
-    in reverse stack
+    reverse $ execState (doStackAnalysis startScope endScope t) []
   where
     startScope t =
         let scopeType = leadType params t

From f55d8c45e567398cfd9effcf08ad6d5706936268 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:30:28 -0400
Subject: [PATCH 05/16] Simplify causesSubshell

---
 src/ShellCheck/AnalyzerLib.hs | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 8f168dc..fd0f46d 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -460,11 +460,9 @@ leadType params t =
 
     causesSubshell = do
         (T_Pipeline _ _ list) <- parentPipeline
-        if length list <= 1
-            then return False
-            else if not $ hasLastpipe params
-                then return True
-                else return . not $ (getId . head $ reverse list) == getId t
+        return $ case list of
+            _:_:_ -> not (hasLastpipe params) || getId (last list) /= getId t
+            _ -> False
 
 getModifiedVariables t =
     case t of

From f833ee3d5ada7cf4d648fb16ef143e09550b9fac Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:35:09 -0400
Subject: [PATCH 06/16] Use a list comprehension instead of a concatMap with
 extra lists

---
 src/ShellCheck/AnalyzerLib.hs | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index fd0f46d..31ee431 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -467,11 +467,7 @@ leadType params t =
 getModifiedVariables t =
     case t of
         T_SimpleCommand _ vars [] ->
-            concatMap (\x -> case x of
-                                T_Assignment id _ name _ w  ->
-                                    [(x, x, name, dataTypeFrom DataString w)]
-                                _ -> []
-                      ) vars
+            [(x, x, name, dataTypeFrom DataString w) | x@(T_Assignment id _ name _ w) <- vars]
         c@T_SimpleCommand {} ->
             getModifiedVariableCommand c
 

From 67e091674ed35cb20b9053e99e4d38e3d68286e8 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:36:10 -0400
Subject: [PATCH 07/16] Remove unnecessary maybeToList

The functions we use here are polymorphic enough to work in the [] monad,
so there's no point to use them in the Maybe monad and then convert.
---
 src/ShellCheck/AnalyzerLib.hs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 31ee431..188054c 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -475,7 +475,7 @@ getModifiedVariables t =
             [(t, v, name, DataString $ SourceFrom [v])]
         TA_Unary _ "|++" v@(TA_Variable _ name _)  ->
             [(t, v, name, DataString $ SourceFrom [v])]
-        TA_Assignment _ op (TA_Variable _ name _) rhs -> maybeToList $ do
+        TA_Assignment _ op (TA_Variable _ name _) rhs -> do
             guard $ op `elem` ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
             return (t, t, name, DataString $ SourceFrom [rhs])
 
@@ -487,17 +487,17 @@ getModifiedVariables t =
 
         -- Count [[ -v foo ]] as an "assignment".
         -- This is to prevent [ -v foo ] being unassigned or unused.
-        TC_Unary id _ "-v" token -> maybeToList $ do
+        TC_Unary id _ "-v" token -> do
             str <- fmap (takeWhile (/= '[')) $ -- Quoted index
                     flip getLiteralStringExt token $ \x ->
                 case x of
                     T_Glob _ s -> return s -- Unquoted index
-                    _          -> Nothing
+                    _          -> []
 
             guard . not . null $ str
             return (t, token, str, DataString SourceChecked)
 
-        T_DollarBraced _ _ l -> maybeToList $ do
+        T_DollarBraced _ _ l -> do
             let string = bracedString t
             let modifier = getBracedModifier string
             guard $ any (`isPrefixOf` modifier) ["=", ":="]
@@ -747,9 +747,9 @@ getReferencedVariables parents t =
 
     literalizer t = case t of
         T_Glob _ s -> return s    -- Also when parsed as globs
-        _          -> Nothing
+        _          -> []
 
-    getIfReference context token = maybeToList $ do
+    getIfReference context token = do
             str@(h:_) <- getLiteralStringExt literalizer token
             when (isDigit h) $ fail "is a number"
             return (context, token, getBracedReference str)

From f109f9ab9270dd78bd8f8dc2158c9ce4904f599e Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 15:38:16 -0400
Subject: [PATCH 08/16] Remove unnecessary as-patterns

---
 src/ShellCheck/AnalyzerLib.hs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 188054c..543f6e6 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -468,8 +468,8 @@ getModifiedVariables t =
     case t of
         T_SimpleCommand _ vars [] ->
             [(x, x, name, dataTypeFrom DataString w) | x@(T_Assignment id _ name _ w) <- vars]
-        c@T_SimpleCommand {} ->
-            getModifiedVariableCommand c
+        T_SimpleCommand {} ->
+            getModifiedVariableCommand t
 
         TA_Unary _ "++|" v@(TA_Variable _ name _)  ->
             [(t, v, name, DataString $ SourceFrom [v])]
@@ -503,10 +503,10 @@ getModifiedVariables t =
             guard $ any (`isPrefixOf` modifier) ["=", ":="]
             return (t, t, getBracedReference string, DataString $ SourceFrom [l])
 
-        t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&2 modifies foo
+        T_FdRedirect _ ('{':var) op -> -- {foo}>&2 modifies foo
             [(t, t, takeWhile (/= '}') var, DataString SourceInteger) | not $ isClosingFileOp op]
 
-        t@(T_CoProc _ name _) ->
+        T_CoProc _ name _ ->
             [(t, t, fromMaybe "COPROC" name, DataArray SourceInteger)]
 
         --Points to 'for' rather than variable
@@ -730,7 +730,7 @@ getReferencedVariables parents t =
             (t, t, "output")
             ]
 
-        t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&- references and closes foo
+        T_FdRedirect _ ('{':var) op -> -- {foo}>&- references and closes foo
             [(t, t, takeWhile (/= '}') var) | isClosingFileOp op]
         x -> getReferencedVariableCommand x
   where

From e4eb2d157f8211e14b66d0718fa4d90e3fefbd8a Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:03:49 -0400
Subject: [PATCH 09/16] Remove an unnecessary operator section

---
 src/ShellCheck/AnalyzerLib.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 543f6e6..4cd4b5e 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -564,7 +564,7 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
             let params = map getLiteral rest
                 readArrayVars = getReadArrayVariables rest
             in
-                catMaybes . (++ readArrayVars) . takeWhile isJust . reverse $ params
+                catMaybes $ takeWhile isJust (reverse params) ++ readArrayVars
         "getopts" ->
             case rest of
                 opts:var:_ -> maybeToList $ getLiteral var

From 2ebf522a52efe4ef092009f0db6da4cdd25edf5b Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:07:19 -0400
Subject: [PATCH 10/16] Simplify isArrayFlag

---
 src/ShellCheck/AnalyzerLib.hs | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 4cd4b5e..8208a5b 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -669,12 +669,10 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
         map (getLiteralArray . snd)
             (filter (isArrayFlag . fst) (zip args (tail args)))
 
-    isArrayFlag x = fromMaybe False $ do
-        str <- getLiteralString x
-        return $ case str of
-                    '-':'-':_ -> False
-                    '-':str -> 'a' `elem` str
-                    _ -> False
+    isArrayFlag x = case getLiteralString x of
+                       Just ('-':'-':_) -> False
+                       Just ('-':str) -> 'a' `elem` str
+                       _ -> False
 
     -- get the FLAGS_ variable created by a shflags DEFINE_ call
     getFlagVariable (n:v:_) = do

From 4604066c3729766b49da0251786286b6c1ae8caa Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:16:12 -0400
Subject: [PATCH 11/16] Use head instead of (!! 0)

---
 src/ShellCheck/AnalyzerLib.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 8208a5b..c5eaea6 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -798,7 +798,7 @@ getVariablesFromLiteralToken token =
 prop_getVariablesFromLiteral1 =
     getVariablesFromLiteral "$foo${bar//a/b}$BAZ" == ["foo", "bar", "BAZ"]
 getVariablesFromLiteral string =
-    map (!! 0) $ matchAllSubgroups variableRegex string
+    map head $ matchAllSubgroups variableRegex string
   where
     variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
 

From 1cf0aa25e9a76585f34798628cf7cc7d35642970 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:19:18 -0400
Subject: [PATCH 12/16] Simplify dropPrefix

---
 src/ShellCheck/AnalyzerLib.hs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index c5eaea6..26e65e6 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -820,8 +820,8 @@ getBracedReference s = fromMaybe s $
     nameExpansion s `mplus` takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
   where
     noPrefix = dropPrefix s
-    dropPrefix (c:rest) = if c `elem` "!#" then rest else c:rest
-    dropPrefix ""       = ""
+    dropPrefix (c:rest) | c `elem` "!#" = rest
+    dropPrefix cs = cs
     takeName s = do
         let name = takeWhile isVariableChar s
         guard . not $ null name

From ca41440a678879d586320250a4b91913d1256a6e Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:21:07 -0400
Subject: [PATCH 13/16] Simplify getSpecial

---
 src/ShellCheck/AnalyzerLib.hs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 26e65e6..95b236a 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -826,9 +826,8 @@ getBracedReference s = fromMaybe s $
         let name = takeWhile isVariableChar s
         guard . not $ null name
         return name
-    getSpecial (c:_) =
-        if c `elem` "*@#?-$!" then return [c] else fail "not special"
-    getSpecial _ = fail "empty"
+    getSpecial (c:_) | c `elem` "*@#?-$!" = return [c]
+    getSpecial _ = fail "empty or not special"
 
     nameExpansion ('!':rest) = do -- e.g. ${!foo*bar*}
         let suffix = dropWhile isVariableChar rest

From 0cc5ed4563ccd87b200dd41c2801f8d4d79b8f15 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:25:43 -0400
Subject: [PATCH 14/16] Don't bother with asks if you're just immediately
 binding the result anyway

---
 src/ShellCheck/AnalyzerLib.hs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 95b236a..32de46a 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -354,8 +354,8 @@ getClosestCommand tree t =
 
 -- Like above, if koala_man knew Haskell when starting this project.
 getClosestCommandM t = do
-    tree <- asks parentMap
-    return $ getClosestCommand tree t
+    params <- ask
+    return $ getClosestCommand (parentMap params) t
 
 -- Is the token used as a command name (the first word in a T_SimpleCommand)?
 usedAsCommandName tree token = go (getId token) (tail $ getPath tree token)
@@ -377,8 +377,8 @@ getPath tree t = t :
 -- Version of the above taking the map from the current context
 -- Todo: give this the name "getPath"
 getPathM t = do
-    map <- asks parentMap
-    return $ getPath map t
+    params <- ask
+    return $ getPath (parentMap params) t
 
 isParentOf tree parent child =
     elem (getId parent) . map getId $ getPath tree child
@@ -866,8 +866,8 @@ headOrDefault def _   = def
 
 -- Run a command if the shell is in the given list
 whenShell l c = do
-    shell <- asks shellType
-    when (shell `elem` l ) c
+    params <- ask
+    when (shellType params `elem` l ) c
 
 
 filterByAnnotation asSpec params =

From fb55072302c14d4785875357d4400de736f4eeb9 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:30:59 -0400
Subject: [PATCH 15/16] Implement supportsArrays with pattern-matching

---
 src/ShellCheck/AnalyzerLib.hs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index 32de46a..a3fa29d 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -934,7 +934,9 @@ getOpts string flags = process flags
                 more <- process rest2
                 return $ (flag1, token1) : more
 
-supportsArrays shell = shell == Bash || shell == Ksh
+supportsArrays Bash = True
+supportsArrays Ksh = True
+supportsArrays _ = False
 
 -- Returns true if the shell is Bash or Ksh (sorry for the name, Ksh)
 isBashLike :: Parameters -> Bool

From d22e0aa4a79ddd8182c81898b790c9b9bb850937 Mon Sep 17 00:00:00 2001
From: "Joseph C. Sible" <josephcsible@users.noreply.github.com>
Date: Sun, 5 Apr 2020 16:38:52 -0400
Subject: [PATCH 16/16] Simplify process

Note to self: This is a lot like foldr or traverse, and would be trivial to
implement as such if it didn't need to peek ahead when takesArg is true. I
wonder if there's a clean way to implement it in terms of one of them anyway.
---
 src/ShellCheck/AnalyzerLib.hs | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/src/ShellCheck/AnalyzerLib.hs b/src/ShellCheck/AnalyzerLib.hs
index a3fa29d..7c2440b 100644
--- a/src/ShellCheck/AnalyzerLib.hs
+++ b/src/ShellCheck/AnalyzerLib.hs
@@ -919,20 +919,15 @@ getOpts string flags = process flags
     flagMap = Map.fromList $ ("", False) : flagList string
 
     process [] = return []
-    process [(token, flag)] = do
+    process ((token1, flag):rest1) = do
         takesArg <- Map.lookup flag flagMap
-        guard $ not takesArg
-        return [(flag, token)]
-    process ((token1, flag1):rest2@((token2, flag2):rest)) = do
-        takesArg <- Map.lookup flag1 flagMap
-        if takesArg
-            then do
-                guard $ null flag2
-                more <- process rest
-                return $ (flag1, token2) : more
-            else do
-                more <- process rest2
-                return $ (flag1, token1) : more
+        (token, rest) <- if takesArg
+            then case rest1 of
+                (token2, ""):rest2 -> return (token2, rest2)
+                _ -> fail "takesArg without valid arg"
+            else return (token1, rest1)
+        more <- process rest
+        return $ (flag, token) : more
 
 supportsArrays Bash = True
 supportsArrays Ksh = True