tock-mirror/TLP.hs

56 lines
1.7 KiB
Haskell

-- | Top-level process support.
module TLP where
import Control.Monad.Error
import Control.Monad.State
import Data.Generics
import Data.List
import Data.Maybe
import qualified AST as A
import CompState
import Errors
import Metadata
import Types
data TLPChannel = TLPIn | TLPOut | TLPError
deriving (Show, Eq, Typeable, Data)
-- | Get the name of the TLP and the channels it uses.
-- Fail if the process isn't using a valid interface.
tlpInterface :: (CSM m, Die m) => m (A.Name, [TLPChannel])
tlpInterface
= do ps <- get
let mainName = snd $ head $ csMainLocals ps
st <- specTypeOfName mainName
formals <- case st of
A.Proc _ _ fs _ -> return fs
_ -> die "Last definition is not a PROC"
chans <- mapM tlpChannel formals
when ((nub chans) /= chans) $ die "Channels used more than once in TLP"
return (mainName, chans)
where
tlpChannel :: (CSM m, Die m) => A.Formal -> m TLPChannel
tlpChannel (A.Formal _ (A.Chan A.Byte) n)
= do def <- lookupName n
let origN = A.ndOrigName def
case lookup origN tlpChanNames of
Just c -> return c
_ -> die $ "TLP formal " ++ show n ++ " has unrecognised name"
tlpChannel (A.Formal _ _ n)
= die $ "TLP formal " ++ show n ++ " has unrecognised type"
tlpChanNames :: [(String, TLPChannel)]
tlpChanNames
= [ ("in", TLPIn)
, ("kb", TLPIn)
, ("keyb", TLPIn)
, ("keyboard", TLPIn)
, ("out", TLPOut)
, ("scr", TLPOut)
, ("screen", TLPOut)
, ("err", TLPError)
, ("error", TLPError)
]