{-# OPTIONS_GHC -XEmptyDataDecls -XScopedTypeVariables #-}
--------------------------------------------------------------------
-- |
-- Module      : NET.System.Predicate
-- Description : Interface to @System.Predicate@
-- Copyright   : (c) Sigbjorn Finne, 2008
-- License     : BSD3
--
-- Maintainer  : Sigbjorn Finne <sof@forkIO.com>
-- Stability   : provisional
-- Portability : portable
--
-- Bindings to the @System.Predicate@ generic delegate.
-- 
--------------------------------------------------------------------
module NET.System.Predicate (module NET.System.Predicate, module NET.System.Predicate.Type ) where

import NET
import NET.System.Predicate.Type

newPredicate :: (Arg ty, Type ty)
             => (ty -> Predicate ty a -> IO Bool)
             -> IO (Predicate ty a)
newPredicate hPred = do
  let ts = tyName (tyFunArg hPred)
  obj <- newDelegator2 (toGenericTypeString "System.Predicate" ts)
                       ( \ a b -> do
			 (v,_) <- fromArgs [a]
			 th <- mkObject b
			 hPred v th)
  return (castObjTy obj)

invokePredicate :: (Arg ty, Type ty)
	        => ty
	        -> Predicate obj ty
	        -> IO ()
invokePredicate arg obj = obj # invoke "Invoke" arg