From 2dd7bab9b2060c5a65f66113b3d405babdbeedf7 Mon Sep 17 00:00:00 2001
From: Kazu Yamamoto <kazu@iij.ad.jp>
Date: Thu, 27 Mar 2014 16:22:49 +0900
Subject: [PATCH] packageDoc for sandbox.

---
 Language/Haskell/GhcMod.hs        |  2 ++
 Language/Haskell/GhcMod/PkgDoc.hs | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 Language/Haskell/GhcMod/PkgDoc.hs

diff --git a/Language/Haskell/GhcMod.hs b/Language/Haskell/GhcMod.hs
index af1c885..63a1f03 100644
--- a/Language/Haskell/GhcMod.hs
+++ b/Language/Haskell/GhcMod.hs
@@ -23,6 +23,7 @@ module Language.Haskell.GhcMod (
   , listFlags
   , debugInfo
   , rootInfo
+  , packageDoc
   -- * Converting the 'Ghc' monad to the 'IO' monad
   , withGHC
   , withGHCDummyFile
@@ -46,4 +47,5 @@ import Language.Haskell.GhcMod.Info
 import Language.Haskell.GhcMod.Lang
 import Language.Haskell.GhcMod.Lint
 import Language.Haskell.GhcMod.List
+import Language.Haskell.GhcMod.PkgDoc
 import Language.Haskell.GhcMod.Types
diff --git a/Language/Haskell/GhcMod/PkgDoc.hs b/Language/Haskell/GhcMod/PkgDoc.hs
new file mode 100644
index 0000000..5fc4362
--- /dev/null
+++ b/Language/Haskell/GhcMod/PkgDoc.hs
@@ -0,0 +1,23 @@
+module Language.Haskell.GhcMod.PkgDoc (packageDoc) where
+
+import Control.Applicative ((<$>))
+import Language.Haskell.GhcMod.Types
+import System.Process (readProcess)
+
+-- | Obtaining the package name and the doc path of a module.
+packageDoc :: Options
+           -> Cradle
+           -> ModuleString
+           -> IO String
+packageDoc _ cradle mdl = pkgDoc cradle mdl
+
+pkgDoc :: Cradle -> String -> IO String
+pkgDoc cradle mdl = do
+    pkg <- trim <$> readProcess "ghc-pkg" toModuleOpts []
+    htmlpath <- readProcess "ghc-pkg" ["field", pkg, "haddock-html"] []
+    let ret = pkg ++ " " ++ drop 14 htmlpath
+    return ret
+  where
+    toModuleOpts = ["find-module", "--simple-output"] ++ cradlePackageDbOpts cradle ++ [mdl]
+    trim = fst . break (== '\n')
+