Add Shake.FilePath

Development/Shake/FilePath.hs

@@ -0,0 +1,56 @@
+-- | Useful 'System.FilePath' wrapper around Shake.
+
+module Development.Shake.FilePath
+    (startShake
+    ,target
+    ,need
+    ,want
+    ,Target(Target)
+    ,unTarget
+    ,Rules
+    ,Action
+    ,CmdOption(..)
+    ,Shake.cmd)
+    where
+
+import           Control.Monad.IO.Class
+import           Development.Shake (Rules,Action,CmdOption(..))
+import qualified Development.Shake as Shake
+import           Filesystem.Path.CurrentOS (FilePath)
+import qualified Filesystem.Path.CurrentOS as FP
+import           Prelude hiding (FilePath)
+import           System.Environment
+
+-- | A simple opaque wrapper for the "target" abstraction.
+newtype Target = Target
+    { unTarget :: FilePath
+    }
+
+-- | Start Shake with the given data directory.
+startShake :: MonadIO m => Int -> FilePath -> Rules () -> m ()
+startShake threads dir rules =
+    liftIO (withArgs [] $
+                Shake.shakeArgs
+                          Shake.shakeOptions
+                          { Shake.shakeFiles = FP.encodeString dir
+                          , Shake.shakeThreads = threads
+                          } $
+                rules)
+
+-- | Declare a target, returning the target name.
+target :: Target -> Action () -> Rules Target
+target name act = do
+    (FP.encodeString
+         (unTarget name)) Shake.*>
+        const act
+    return name
+
+-- | Need the given dependencies.
+need :: [Target] -> Action ()
+need xs = Shake.need $
+    map (FP.encodeString . unTarget) xs
+
+-- | Need the given dependencies.
+want :: [Target] -> Rules ()
+want xs = Shake.want
+        (map (FP.encodeString . unTarget) xs)