Remove unnecessary uses of head

This commit is contained in:
Joseph C. Sible 2020-02-09 22:51:10 -05:00
parent c95914f9b3
commit 6d06103cab
5 changed files with 14 additions and 15 deletions

View file

@ -255,7 +255,7 @@ determineShell fallbackShell t = fromMaybe Bash $
executableFromShebang :: String -> String
executableFromShebang = shellFor
where
shellFor s | "/env " `isInfixOf` s = head (drop 1 (words s)++[""])
shellFor s | "/env " `isInfixOf` s = headOrDefault "" (drop 1 $ words s)
shellFor s | ' ' `elem` s = shellFor $ takeWhile (/= ' ') s
shellFor s = reverse . takeWhile (/= '/') . reverse $ s
@ -295,7 +295,7 @@ isQuoteFree = isQuoteFreeNode False
isQuoteFreeNode strict tree t =
(isQuoteFreeElement t == Just True) ||
head (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t) ++ [False])
headOrDefault False (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t))
where
-- Is this node self-quoting in itself?
isQuoteFreeElement t =
@ -758,9 +758,8 @@ getReferencedVariables parents t =
_ -> Nothing
getIfReference context token = maybeToList $ do
str <- getLiteralStringExt literalizer token
guard . not $ null str
when (isDigit $ head str) $ fail "is a number"
str@(h:_) <- getLiteralStringExt literalizer token
when (isDigit h) $ fail "is a number"
return (context, token, getBracedReference str)
isDereferencing = (`elem` ["-eq", "-ne", "-lt", "-le", "-gt", "-ge"])