Found some interesting GHC API calls

examples/A.hs

@@ -0,0 +1,6 @@
+module A where
+
+f :: Int -> Int -> Int
+f x y = x + y
+
+data SomeData = NotReally | JustOne Int | JustTwo Int Double

quick-version.cabal

@@ -19,4 +19,6 @@ executable quickver
 
   build-depends:
       base       == 4.*
+    , ghc        == 7.2.*
+    , ghc-paths  == 0.1.*
     , QuickCheck == 2.4.*

src/Main.hs

@@ -1,4 +1,39 @@
 module Main (main) where
 
+import qualified DynFlags as G
+import           Data.Maybe (catMaybes)
+import qualified DataCon as G
+import qualified GHC as G
+import           GHC.Paths (libdir)
+import qualified Outputable as G
+import qualified TyCon as G
+import qualified Var as G
+
 main :: IO ()
-main = putStrLn "Quick Version 0.1"
+main = do
+   res <- example
+   mapM_ (putStrLn . G.showSDoc . G.ppr) res
+
+example :: IO [G.Type]
+example =
+    G.defaultErrorHandler G.defaultLogAction $ do
+    G.runGhc (Just libdir) $ do
+        dflags <- G.getSessionDynFlags
+        G.setSessionDynFlags dflags
+        target <- G.guessTarget "examples/A.hs" Nothing
+        G.setTargets [target]
+        G.load G.LoadAllTargets
+
+        m <- G.findModule (G.mkModuleName "A") Nothing
+        (Just info) <- G.getModuleInfo m
+
+        exports <- mapM (G.lookupName) (G.modInfoExports info)
+
+        return $ map extractType $ catMaybes exports
+
+extractType :: G.TyThing -> G.Type
+extractType (G.AnId var)      = G.varType var
+extractType (G.ATyCon tycon)  = G.tyConKind tycon
+extractType (G.ADataCon dcon) = G.dataConRepType dcon
+extractType (G.ACoAxiom _)    = error "extractType: ACoAxiom"
+extractType (G.AClass _)      = error "extractType: AClass"