From 4202ca1ea20916c70ad83602decb0126de78b945 Mon Sep 17 00:00:00 2001
From: Kazu Yamamoto <kazu@iij.ad.jp>
Date: Fri, 2 Apr 2010 14:40:06 +0900
Subject: [PATCH] supporting "lang" command.

---
 GHCMod.hs |  2 ++
 Lang.hs   | 14 ++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 Lang.hs

diff --git a/GHCMod.hs b/GHCMod.hs
index fdb7830..a26cc3f 100644
--- a/GHCMod.hs
+++ b/GHCMod.hs
@@ -5,6 +5,7 @@ import Check
 import Control.Exception hiding (try)
 import List
 import Param
+import Lang
 import Prelude hiding (catch)
 import System.Console.GetOpt
 import System.Environment (getArgs)
@@ -63,6 +64,7 @@ main = flip catch handler $ do
       "browse" -> browseModule opt (cmdArg !! 1)
       "list"   -> listModules opt
       "check"  -> checkSyntax opt (cmdArg !! 1)
+      "lang"   -> listLanguages opt
       _        -> error usage
     putStr res
   where
diff --git a/Lang.hs b/Lang.hs
new file mode 100644
index 0000000..423f6c9
--- /dev/null
+++ b/Lang.hs
@@ -0,0 +1,14 @@
+module Lang where
+
+import Control.Applicative
+import Param
+import System.IO
+import System.Process
+
+listLanguages :: Options -> IO String
+listLanguages opt = convert opt . lines <$> getLangs opt
+
+getLangs :: Options -> IO String
+getLangs opt = do
+  (_,hout,_,_) <- runInteractiveProcess (ghc opt) ["--supported-languages"] Nothing Nothing
+  hGetContents hout