Why do Names defined in the current module lack a module name?

[Johan Tibell]

On Wed, Apr 3, 2013 at 5:14 AM, Simon Peyton-Jones
<simonpj at microsoft.com> wrote:
> I've just been checking. The top level name *is* (and remains) an External Name. See below.
>
> Don't be misled by the dump labelled "Typechecker" (-ddump-tc).  It is carefully printing things as in error messages, with as little qualification as possible; since 'mysum' is in scope unqualified here, it's printed unqualified. But it's an External Name all right. Use -dppr-debug to see it in its full glory

I'm not dumping the names using a command line flag, but using a
program that uses the GHC API that I wrote. This is how I use the GHC
API to get hold of the AST once the source code has been compiled:

forEachM z xs f = foldM f z xs

indexSymbols :: ModuleGraph -> Ghc Builder.Builder
indexSymbols graph = forEachM Builder.new graph $ \ builder ms -> do
    let filename = msHsFilePath ms
    handleSourceError printErrorAndExit $ do
        liftIO $ putStrLn ("Loading " ++ filename ++ " ...")
        mod <- loadModule =<< typecheckModule =<< parseModule ms
        case mod of
            _ | isBootSummary ms -> return builder
            _ | Just (group, _, _, _) <- renamedSource mod -> do
                let modname = moduleName $ ms_mod ms
                    builder' = invertedIndex builder modname $ bagToList $
                               symbols group (typecheckedSource mod)
-- ** HERE **
                liftIO $ print $ builder'
                return $! builder'
            _  -> liftIO $ exitWith (ExitFailure 1)
  where
    printErrorAndExit e = do
        printException e
        liftIO $ exitWith (ExitFailure 1)

So I invoke my AST traversal function 'symbols' (which just extracts
all the Names in the AST into a Bag) on the AST returned by
'typecheckedSource mod'. This is the AST I expected to have fully
qualified names but doesn't.