module Foreign.Lua.Module.SystemUtils
( AnyValue (..)
, Callback (..)
, invoke
, invokeWithFilePath
, ioToLua
)
where
import Control.Exception (IOException, try)
import Foreign.Lua (Lua, NumResults(..), Peekable, Pushable, StackIndex)
import qualified Foreign.Lua as Lua
newtype Callback = Callback StackIndex
instance Peekable Callback where
peek :: StackIndex -> Lua Callback
peek idx :: StackIndex
idx = do
Bool
isFn <- StackIndex -> Lua Bool
Lua.isfunction StackIndex
idx
if Bool
isFn
then Callback -> Lua Callback
forall (m :: * -> *) a. Monad m => a -> m a
return (StackIndex -> Callback
Callback StackIndex
idx)
else String -> Lua Callback
forall a. String -> Lua a
Lua.throwException "Function expected"
instance Pushable Callback where
push :: Callback -> Lua ()
push (Callback idx :: StackIndex
idx) = StackIndex -> Lua ()
Lua.pushvalue StackIndex
idx
newtype AnyValue = AnyValue { AnyValue -> StackIndex
fromAnyValue :: StackIndex }
instance Peekable AnyValue where
peek :: StackIndex -> Lua AnyValue
peek = AnyValue -> Lua AnyValue
forall (m :: * -> *) a. Monad m => a -> m a
return (AnyValue -> Lua AnyValue)
-> (StackIndex -> AnyValue) -> StackIndex -> Lua AnyValue
forall b c a. (b -> c) -> (a -> b) -> a -> c
. StackIndex -> AnyValue
AnyValue
instance Pushable AnyValue where
push :: AnyValue -> Lua ()
push (AnyValue idx :: StackIndex
idx) = StackIndex -> Lua ()
Lua.pushvalue StackIndex
idx
invoke :: Callback -> Lua NumResults
invoke :: Callback -> Lua NumResults
invoke callback :: Callback
callback = do
StackIndex
oldTop <- Lua StackIndex
Lua.gettop
Callback -> Lua ()
forall a. Pushable a => a -> Lua ()
Lua.push Callback
callback
NumArgs -> NumResults -> Lua ()
Lua.call 0 NumResults
Lua.multret
StackIndex
newTop <- Lua StackIndex
Lua.gettop
NumResults -> Lua NumResults
forall (m :: * -> *) a. Monad m => a -> m a
return (NumResults -> Lua NumResults)
-> (StackIndex -> NumResults) -> StackIndex -> Lua NumResults
forall b c a. (b -> c) -> (a -> b) -> a -> c
. CInt -> NumResults
NumResults (CInt -> NumResults)
-> (StackIndex -> CInt) -> StackIndex -> NumResults
forall b c a. (b -> c) -> (a -> b) -> a -> c
. CInt -> CInt
forall a b. (Integral a, Num b) => a -> b
fromIntegral (CInt -> CInt) -> (StackIndex -> CInt) -> StackIndex -> CInt
forall b c a. (b -> c) -> (a -> b) -> a -> c
. StackIndex -> CInt
Lua.fromStackIndex (StackIndex -> Lua NumResults) -> StackIndex -> Lua NumResults
forall a b. (a -> b) -> a -> b
$
StackIndex
newTop StackIndex -> StackIndex -> StackIndex
forall a. Num a => a -> a -> a
- StackIndex
oldTop
invokeWithFilePath :: Callback -> FilePath -> Lua NumResults
invokeWithFilePath :: Callback -> String -> Lua NumResults
invokeWithFilePath callback :: Callback
callback filename :: String
filename = do
StackIndex
oldTop <- Lua StackIndex
Lua.gettop
Callback -> Lua ()
forall a. Pushable a => a -> Lua ()
Lua.push Callback
callback
String -> Lua ()
forall a. Pushable a => a -> Lua ()
Lua.push String
filename
NumArgs -> NumResults -> Lua ()
Lua.call (CInt -> NumArgs
Lua.NumArgs 1) NumResults
Lua.multret
StackIndex
newTop <- Lua StackIndex
Lua.gettop
NumResults -> Lua NumResults
forall (m :: * -> *) a. Monad m => a -> m a
return (NumResults -> Lua NumResults)
-> (StackIndex -> NumResults) -> StackIndex -> Lua NumResults
forall b c a. (b -> c) -> (a -> b) -> a -> c
. CInt -> NumResults
NumResults (CInt -> NumResults)
-> (StackIndex -> CInt) -> StackIndex -> NumResults
forall b c a. (b -> c) -> (a -> b) -> a -> c
. CInt -> CInt
forall a b. (Integral a, Num b) => a -> b
fromIntegral (CInt -> CInt) -> (StackIndex -> CInt) -> StackIndex -> CInt
forall b c a. (b -> c) -> (a -> b) -> a -> c
. StackIndex -> CInt
Lua.fromStackIndex (StackIndex -> Lua NumResults) -> StackIndex -> Lua NumResults
forall a b. (a -> b) -> a -> b
$
StackIndex
newTop StackIndex -> StackIndex -> StackIndex
forall a. Num a => a -> a -> a
- StackIndex
oldTop
ioToLua :: IO a -> Lua a
ioToLua :: IO a -> Lua a
ioToLua action :: IO a
action = do
Either IOException a
result <- IO (Either IOException a) -> Lua (Either IOException a)
forall (m :: * -> *) a. MonadIO m => IO a -> m a
Lua.liftIO (IO a -> IO (Either IOException a)
forall e a. Exception e => IO a -> IO (Either e a)
try IO a
action)
case Either IOException a
result of
Right result' :: a
result' -> a -> Lua a
forall (m :: * -> *) a. Monad m => a -> m a
return a
result'
Left err :: IOException
err -> String -> Lua a
forall a. String -> Lua a
Lua.throwException (IOException -> String
forall a. Show a => a -> String
show (IOException
err :: IOException))