Proper data type for platform

Author: hdgarrood

src/Node/Platform.purs

@@ -0,0 +1,43 @@
+-- | This module defines data type for the different platforms supported by
+-- | Node.js
+module Node.Platform where
+
+import Prelude
+import Data.Function (on)
+import Data.Maybe (Maybe(..))
+
+data Platform
+  = Darwin
+  | FreeBSD
+  | Linux
+  | SunOS
+  | Win32
+
+-- | The String representation for a platform, recognised by Node.js.
+toString :: Platform -> String
+toString Darwin  = "darwin"
+toString FreeBSD = "freebsd"
+toString Linux   = "linux"
+toString SunOS   = "sunos"
+toString Win32   = "win32"
+
+fromString :: String -> Maybe Platform
+fromString "darwin"  = Just Darwin
+fromString "freebsd" = Just FreeBSD
+fromString "linux"   = Just Linux
+fromString "sunos"   = Just SunOS
+fromString "win32"   = Just Win32
+fromString _         = Nothing
+
+instance showPlatform :: Show Platform where
+  show Darwin  = "Darwin"
+  show FreeBSD = "FreeBSD"
+  show Linux   = "Linux"
+  show SunOS   = "SunOS"
+  show Win32   = "Win32"
+
+instance eqPlatform :: Eq Platform where
+  eq = eq `on` toString
+
+instance ordPlatform :: Ord Platform where
+  compare = compare `on` toString

src/Node/Process.purs

@@ -26,12 +26,15 @@ import Prelude
 import Control.Monad.Eff
 import Control.Monad.Eff.Console (CONSOLE())
 import Control.Monad.Eff.Exception (EXCEPTION())
-import Control.Monad.Eff.Unsafe (unsafePerformEff)
 import Data.Maybe (Maybe())
+import Data.Maybe.Unsafe (fromJust)
 import Data.StrMap (StrMap())
 import Data.StrMap as StrMap
 import Node.Stream (Readable(), Writable())
 
+import Node.Platform (Platform())
+import Node.Platform as Platform
+
 -- | An effect tracking interaction with the global `process` object.
 foreign import data PROCESS :: !
 
@@ -94,8 +97,8 @@ foreign import setEnv :: forall eff. String -> String -> Eff (process :: PROCESS
 pid :: Int
 pid = process.pid
 
-platform :: String
-platform = process.platform
+platform :: Platform
+platform = fromJust (Platform.fromString process.platform)
 
 -- | Cause the process to exit with the supplied integer code. An exit code
 -- | of 0 is normally considered successful, and anything else is considered a