Add ‘compileMustacheDir'’ and ‘getMustacheFilesInDir'’

CHANGELOG.md

@@ -1,3 +1,9 @@
+## Stache 1.2.0
+
+* Added `compileMustacheDir'` and `getMusthacheFilesInDir'` that allow for a
+  custom template predicate. Also exposed `isMustacheFile` as the default
+  predicate used by functions like `compileMustacheDir`.
+
 ## Stache 1.1.2
 
 * Fixed compilation of the test suite with Cabal 2.0/GHC 8.2.1.

Text/Mustache.hs

@@ -82,6 +82,7 @@ module Text.Mustache
   , displayMustacheWarning
     -- * Compiling
   , compileMustacheDir
+  , compileMustacheDir'
   , compileMustacheFile
   , compileMustacheText
     -- * Rendering

Text/Mustache/Compile.hs

@@ -15,7 +15,10 @@
 
 module Text.Mustache.Compile
   ( compileMustacheDir
+  , compileMustacheDir'
   , getMustacheFilesInDir
+  , getMustacheFilesInDir'
+  , isMustacheFile
   , compileMustacheFile
   , compileMustacheText )
 where
@@ -43,13 +46,27 @@ import Control.Applicative
 --
 -- The action can throw the same exceptions as 'getDirectoryContents', and
 -- 'T.readFile'.
+--
+-- > compileMustacheDir = complieMustacheDir' isMustacheFile
 
 compileMustacheDir :: MonadIO m
   => PName             -- ^ Which template to select after compiling
   -> FilePath          -- ^ Directory with templates
   -> m Template        -- ^ The resulting template
-compileMustacheDir pname path =
-  getMustacheFilesInDir path >>=
+compileMustacheDir = compileMustacheDir' isMustacheFile
+
+-- | The same as 'compileMustacheDir', but allows using a custom predicate
+-- for template selection.
+--
+-- @since 1.2.0
+
+compileMustacheDir' :: MonadIO m
+  => (FilePath -> Bool) -- ^ Template selection predicate
+  -> PName             -- ^ Which template to select after compiling
+  -> FilePath          -- ^ Directory with templates
+  -> m Template        -- ^ The resulting template
+compileMustacheDir' predicate pname path =
+  getMustacheFilesInDir' predicate path >>=
   liftM selectKey . foldM f (Template undefined M.empty)
   where
     selectKey t = t { templateActual = pname }
@@ -65,10 +82,30 @@ compileMustacheDir pname path =
 getMustacheFilesInDir :: MonadIO m
   => FilePath          -- ^ Directory with templates
   -> m [FilePath]
-getMustacheFilesInDir path = liftIO $
+getMustacheFilesInDir = getMustacheFilesInDir' isMustacheFile
+
+-- | Return a list of templates found via a predicate in given directory.
+-- The returned paths are absolute.
+--
+-- @since 1.2.0
+
+getMustacheFilesInDir' :: MonadIO m
+  => (FilePath -> Bool) -- ^ Mustache file selection predicate
+  -> FilePath          -- ^ Directory with templates
+  -> m [FilePath]
+getMustacheFilesInDir' predicate path = liftIO $
   getDirectoryContents path >>=
-  filterM isMustacheFile . fmap (F.combine path) >>=
+  filterM f . fmap (F.combine path) >>=
   mapM makeAbsolute
+  where
+    f p = (&& predicate p) <$> doesFileExist p
+
+-- | The default Mustache file predicate.
+--
+-- @since 1.2.0
+
+isMustacheFile :: FilePath -> Bool
+isMustacheFile path = F.takeExtension path == ".mustache"
 
 -- | Compile a single Mustache template and select it.
 --
@@ -97,14 +134,6 @@ compileMustacheText pname txt =
 ----------------------------------------------------------------------------
 -- Helpers
 
--- | Check if a given 'FilePath' points to a mustache file.
-
-isMustacheFile :: FilePath -> IO Bool
-isMustacheFile path = do
-  exists <- doesFileExist path
-  let rightExtension = F.takeExtension path == ".mustache"
-  return (exists && rightExtension)
-
 -- | Build a 'PName' from given 'FilePath'.
 
 pathToPName :: FilePath -> PName

Text/Mustache/Compile/TH.hs

@@ -21,6 +21,7 @@
 
 module Text.Mustache.Compile.TH
   ( compileMustacheDir
+  , compileMustacheDir'
   , compileMustacheFile
   , compileMustacheText
   , mustache )
@@ -54,13 +55,29 @@ dataToExpQ _ _ = fail "The feature requires at least GHC 8 to work"
 -- recognized. This function /does not/ scan the directory recursively.
 --
 -- This version compiles the templates at compile time.
+--
+-- > compileMustacheDir = compileMustacheDir' isMustacheFile
 
 compileMustacheDir
   :: PName             -- ^ Which template to select after compiling
   -> FilePath          -- ^ Directory with templates
   -> Q Exp             -- ^ The resulting template
-compileMustacheDir pname path = do
-  runIO (C.getMustacheFilesInDir path) >>= mapM_ addDependentFile
+compileMustacheDir = compileMustacheDir' C.isMustacheFile
+
+-- | The same as 'compileMustacheDir', but allows using a custom predicate
+-- for template selection.
+--
+-- This version compiles the templates at compile time.
+--
+-- @since 1.2.0
+
+compileMustacheDir'
+  :: (FilePath -> Bool) -- ^ Template selection predicate
+  -> PName             -- ^ Which template to select after compiling
+  -> FilePath          -- ^ Directory with templates
+  -> Q Exp             -- ^ The resulting template
+compileMustacheDir' predicate pname path = do
+  runIO (C.getMustacheFilesInDir' predicate path) >>= mapM_ addDependentFile
   (runIO . try) (C.compileMustacheDir pname path) >>= handleEither
 
 -- | Compile single Mustache template and select it.

stack.yaml

@@ -1,6 +1,6 @@
-resolver: lts-9.0
+resolver: lts-9.6
 packages:
 - '.'
 extra-deps:
 - hspec-megaparsec-1.0.0
-- megaparsec-6.0.0
+- megaparsec-6.2.0