On Sun, Jun 17, 2012 at 2:20 AM, Heinrich Apfelmus
Johan Tibell wrote:
I've modified the proposal (in an earlier email) to be to add getExecutablePath. We'll implement it using the methods Simon linked to, which I believe are the same as used in executable-path.
Ah, ok. That works for me.
Reading Simon Hengel's email, I think that distinguishing between different invocation methods (program, script, interactive) via a data type
data ExecutablePath = Binary FilePath | Script FilePath | Interactive
is an excellent idea! This allows us to use the getExecutablePath both in a compiled program and for testing in GHCi.
I'm a bit undecided whether this distinction is useful. If the user is really looking for the executable path there's not much to do except call error if the return value is Script or Interactive. In addition, I don't know how to implement this function correctly. For example, if you alias ghc to another name the heuristic in the executable-path package fails: -- | An experimental hack which tries to figure out if the program -- was run with @runghc@ or @runhaskell@ or @ghci@, and then tries to find -- out the directory of the /source/ (or object file). -- -- GHC only. getScriptPath :: IO ScriptPath getScriptPath = do fargs <- getFullArgs exec <- getExecutablePath let (pt,fn) = splitFileName exec case fargs of [] -> return (Executable exec) _ -> case map toLower fn of #ifdef mingw32_HOST_OS "ghc.exe" -> do #else "ghc" -> do #endif case find f1 fargs of Just s -> do path <- canonicalizePath $ init (drop n1 s) return $ RunGHC path Nothing -> case findIndex f2 fargs of Just i -> return Interactive Nothing -> return (Executable exec) _ -> return (Executable exec) where f1 xs = take n1 xs == s1 s1 = ":set prog \"" n1 = length s1 f2 xs = xs == "--interactive"