module Basis.MVar (entries) where

import Data.Typeable (Typeable)
import BasisUtils
import AST
import Util
import Value (Value, Valuable(..))

import qualified Data.Loc

import qualified Control.Concurrent.MVar as MV

newtype MVar = MVar { unMVar :: MV.MVar Value }
  deriving (Eq, Typeable)

instance Valuable MVar where
  veq = (==)
  vppr _ = text "#<mvar>"

entries :: [Entry Raw]
entries  = [
    dec [sgQ| type `a mvar qualifier U |],
    fun "new" -: [ty| all `a. `a -> `a mvar |]
      -= liftM MVar . MV.newMVar,
    fun "newEmpty"
                 -: [ty| all `a. unit -> `a mvar |]
      -= \() -> MVar `liftM` MV.newEmptyMVar,
    fun "take"
                 -: [ty| all `a. `a mvar -> `a |]
      -= MV.takeMVar . unMVar,
    fun "put"
                 -: [ty| all `a. `a mvar -> `a -> unit |]
      -= MV.putMVar . unMVar,
    fun "read"
                 -: [ty| all 'a. 'a mvar -> 'a |] -- important!
      -= MV.readMVar . unMVar,
    fun "swap"
                 -: [ty| all `a. `a mvar -> `a -> `a |]
      -= MV.swapMVar . unMVar,
    fun "tryTake"
                 -: [ty| all `a. `a mvar -> `a option |]
      -= MV.tryTakeMVar . unMVar,
    fun "tryPut"
                 -: [ty| all `a. `a mvar -> `a -> bool |]
      -= MV.tryPutMVar . unMVar,
    fun "isEmpty"
                 -: [ty| all `a. `a mvar -> bool |]
      -= MV.isEmptyMVar . unMVar,
    fun "callWith"
                 -: [ty| all `a `b. `a mvar -> (`a -> `b) -> `b |]
      -= \mv callback -> MV.withMVar (unMVar mv) (vapp callback),
    fun "modify_"
                 -: [ty| all `a. `a mvar -> (`a -> `a) -> unit |]
      -= \mv callback -> MV.modifyMVar_ (unMVar mv) (vapp callback),
    fun "modify"
                 -: [ty| all `a `b. `a mvar -> (`a -> `a * `b) -> `b |]
      -= \mv callback -> MV.modifyMVar (unMVar mv) $ \v -> do
                           result <- vapp callback v
                           (vprjM result :: IO (Value, Value))
  ]