ghc-mod find (#203).

Language/Haskell/GhcMod.hs

@@ -24,12 +24,14 @@ module Language.Haskell.GhcMod (
   , debugInfo
   , rootInfo
   , packageDoc
+  , findSymbol
   ) where
 
 import Language.Haskell.GhcMod.Browse
 import Language.Haskell.GhcMod.Check
 import Language.Haskell.GhcMod.Cradle
 import Language.Haskell.GhcMod.Debug
+import Language.Haskell.GhcMod.Find
 import Language.Haskell.GhcMod.Flag
 import Language.Haskell.GhcMod.Info
 import Language.Haskell.GhcMod.Lang

Language/Haskell/GhcMod/Find.hs

@@ -2,14 +2,15 @@
 
 module Language.Haskell.GhcMod.Find where
 
+import Control.Monad (void)
 import Data.Function (on)
 import Data.List (groupBy, sort)
 import Data.Maybe (fromMaybe)
 import GHC (Ghc)
 import qualified GHC as G
-import Language.Haskell.GhcMod
 import Language.Haskell.GhcMod.Browse (browseAll)
-import Language.Haskell.GhcMod.Types (convert)
+import Language.Haskell.GhcMod.GHCApi
+import Language.Haskell.GhcMod.Types
 
 #ifndef MIN_VERSION_containers
 #define MIN_VERSION_containers(x,y,z) 1
@@ -23,12 +24,18 @@ import qualified Data.Map.Strict as M
 import Data.Map (Map)
 import qualified Data.Map as M
 #endif
+import Control.Applicative ((<$>))
 
 -- | Type of key for `SymMdlDb`.
 type Symbol = String
 -- | Database from 'Symbol' to modules.
 newtype SymMdlDb = SymMdlDb (Map Symbol [ModuleString])
 
+findSymbol :: Options -> Cradle -> Symbol -> IO String
+findSymbol opt cradle sym = withGHC' $ do
+    void $ initializeFlagsWithCradle opt cradle [] False
+    lookupSym opt sym <$> getSymMdlDb
+
 -- | Creating 'SymMdlDb'.
 getSymMdlDb :: Ghc SymMdlDb
 getSymMdlDb = do

src/GHCMod.hs

@@ -35,6 +35,7 @@ usage =    "ghc-mod version " ++ showVersion version ++ "\n"
         ++ "\t ghc-mod debug" ++ ghcOptHelp ++ "\n"
         ++ "\t ghc-mod info" ++ ghcOptHelp ++ "<HaskellFile> <module> <expression>\n"
         ++ "\t ghc-mod type" ++ ghcOptHelp ++ "<HaskellFile> <module> <line-no> <column-no>\n"
+        ++ "\t ghc-mod find <symbol>\n"
         ++ "\t ghc-mod lint [-h opt] <HaskellFile>\n"
         ++ "\t ghc-mod root\n"
         ++ "\t ghc-mod doc <module>\n"
@@ -114,6 +115,7 @@ main = flip E.catches handlers $ do
       "debug"  -> debugInfo opt cradle
       "info"   -> nArgs 3 infoExpr opt cradle cmdArg1 cmdArg3
       "type"   -> nArgs 4 $ typeExpr opt cradle cmdArg1 (read cmdArg3) (read cmdArg4)
+      "find"   -> nArgs 1 $ findSymbol opt cradle cmdArg1
       "lint"   -> nArgs 1 withFile (lintSyntax opt) cmdArg1
       "root"   -> rootInfo opt cradle
       "doc"    -> nArgs 1 $ packageDoc opt cradle cmdArg1