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authorDougBeardsley <>2010-12-14 00:19:29 (GMT)
committerLuite Stegeman <luite@luite.com>2010-12-14 00:19:29 (GMT)
commitd50ff970ec6f851e286b1868308bc8739c15d54d (patch)
treed19b47362ea24a712b3d851307058da690aa8432 /src
version 0.10.1
Diffstat (limited to 'src')
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+{-|
+
+This is a very simple project containing a few code style checks for use in
+git hooks for the Snap Framework. Hopefully we'll get some more sophisticated
+checks and automatic fixes implemented eventually.
+
+-}
+module Main where
+
+import System
+
+import qualified Data.Text as T
+import qualified Data.Text.IO as TI
+import Data.Text (Text)
+
+
+------------------------------------------------------------------------------
+-- | A check is a function that processes a Text and returns a Just String if
+-- there is a problem.
+type Check = Text -> Maybe String
+
+
+------------------------------------------------------------------------------
+-- | A problem consists of a line number and a string description.
+data Problem = Problem {
+ probLine :: Int,
+ probDescription :: String
+}
+
+
+------------------------------------------------------------------------------
+-- Style checks
+------------------------------------------------------------------------------
+
+------------------------------------------------------------------------------
+-- | Checks for trailing spaces on a line.
+trailingSpaces :: Check
+trailingSpaces line = if T.length (T.takeWhile (==' ') $ T.reverse line) == 0
+ then Nothing
+ else Just "Line has trailing spaces"
+
+
+------------------------------------------------------------------------------
+-- | Checks for tab charcters anywhere on a line.
+noTabs :: Check
+noTabs line = fmap (const "Line contains tab(s).") $ T.find (=='\t') line
+
+
+------------------------------------------------------------------------------
+-- | Ensures line length is 78 characters or less.
+lineLength :: Int -> Check
+lineLength n line =
+ if T.length line <= n
+ then Nothing
+ else Just "Line too long"
+
+
+------------------------------------------------------------------------------
+-- | Static list of line-oriented checks to use.
+lineChecks :: [Check]
+lineChecks = [lineLength 78, noTabs, trailingSpaces]
+
+
+------------------------------------------------------------------------------
+-- Infrastructure
+------------------------------------------------------------------------------
+
+------------------------------------------------------------------------------
+-- | Applies a list of checks to a list of lines. Returns a list of
+-- 'Problem's.
+onLines :: [Check] -> [Text] -> [Problem]
+onLines fs thelines = concat $ map (go 1 thelines) fs
+ where
+ go _ [] _ = []
+ go num (l:ls) f = case f l of
+ Nothing -> go (num+1) ls f
+ Just er -> (Problem num er) : go (num+1) ls f
+
+
+------------------------------------------------------------------------------
+-- | Breaks a file into lines and runs all the checks on them.
+checkContents :: Text -> [Problem]
+checkContents c = lineChecks `onLines` (T.lines c)
+
+
+------------------------------------------------------------------------------
+-- | Runs checks on the specified file.
+checkFile :: FilePath -> IO (FilePath, [Problem])
+checkFile f = do
+ problems <- return . checkContents =<< TI.readFile f
+ return (f,problems)
+
+
+------------------------------------------------------------------------------
+-- | Checks the style of a list of files, prints the problems, and exits with
+-- a return value appropriate for use in a git hook.
+checkStyle :: [FilePath] -> IO ()
+checkStyle fs = do
+ results <- mapM checkFile fs
+ mapM_ printResults results
+ case results of
+ [] -> exitWith ExitSuccess
+ _ -> exitWith (ExitFailure 1)
+ where
+ printResults (f,ps) = mapM_ (printRes f) ps
+ printRes f p = putStrLn $ f ++ " line " ++ (show $ probLine p) ++
+ ": " ++ (probDescription p)
+
+
+------------------------------------------------------------------------------
+-- | Placeholder for fixing style problems.
+fixStyle :: t -> a
+fixStyle _ = do
+ error "Not implemented"
+
+
+------------------------------------------------------------------------------
+-- | Simple main that takes one command-line parameter of "check" or "fix" and
+-- a list of files to be checked.
+main :: IO ()
+main = do
+ args <- getArgs
+ case args of
+ "check":files -> checkStyle files
+ "fix":files -> fixStyle files
+ _ -> error "Must specify 'check' or 'fix'"
+