{- |

Module : $Id$

Description : CspCASL signatures

Copyright : (c) Markus Roggenbach and Till Mossakowski and Uni Bremen 2004

License : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt

Maintainer : M.Roggenbach@swansea.ac.uk

Stability : provisional

Portability : portable

signatures for CSP-CASL

-}

-- todo: implement isInclusion, computeExt

module CspCASL.SignCSP where

import qualified Data.Map as Map

import qualified Data.Set as S

import CASL.AS_Basic_CASL (SORT, VAR)

import CASL.Sign (emptySign, Sign, sortRel)

import CASL.Morphism (Morphism)

import qualified Common.Doc as Doc

import qualified Common.DocUtils as DocUtils

import Common.Id (Id)

import Common.Lib.Rel (predecessors)

import CspCASL.AS_CspCASL_Process (CHANNEL_NAME, PROCESS_NAME)

-- | A process has zero or more parameter sorts, and a communication

-- alphabet.

data ProcProfile = ProcProfile

{ procArgs :: [SORT]

, procAlphabet :: ProcAlpha

} deriving (Eq, Show)

-- | A process communication alphabet consists of a set of sort names

-- and typed channel names.

data TypedChanName = TypedChanName CHANNEL_NAME SORT

deriving (Eq, Ord, Show)

data CommType = CommTypeSort SORT

| CommTypeChan TypedChanName

deriving (Eq, Ord, Show)

type ProcAlpha = S.Set CommType

type ChanNameMap = Map.Map CHANNEL_NAME SORT

type ProcNameMap = Map.Map PROCESS_NAME ProcProfile

type ProcVarMap = Map.Map VAR SORT

-- Close a communication alphabet under CASL subsort

closeCspCommAlpha :: CspSign -> ProcAlpha -> ProcAlpha

closeCspCommAlpha sig alpha =

S.unions $ S.toList $ S.map (closeOneCspComm sig) alpha

-- Close one CommType under CASL subsort

closeOneCspComm :: CspSign -> CommType -> ProcAlpha

closeOneCspComm sig x =

case x of

(CommTypeSort s) ->

S.map CommTypeSort (cspSubsortPreds sig s)

(CommTypeChan (TypedChanName c s)) ->

(S.map CommTypeSort (cspSubsortPreds sig s))

`S.union`

(S.map (foo c) (cspSubsortPreds sig s))

where foo c s = CommTypeChan $ TypedChanName c s

-- Get the subsorts of a sort from a CspCASL signature

cspSubsortPreds :: CspSign -> SORT -> S.Set SORT

cspSubsortPreds sig s = S.union preds (S.singleton s)

where preds = predecessors (sortRel sig) s

{- Will probably be useful, but doesn't appear to be right now.

-- Extract the sorts from a process alphabet

procAlphaSorts :: ProcAlpha -> S.Set SORT

procAlphaSorts a = stripMaybe $ S.map justSort a

where justSort n = case n of

(CommTypeSort s) -> Just s

_ -> Nothing

-- Extract the typed channel names from a process alphabet

procAlphaChans :: ProcAlpha -> S.Set TypedChanName

procAlphaChans a = stripMaybe $ S.map justChan a

where justChan n = case n of

(CommTypeChan c) -> Just c

_ -> Nothing

-- Given a set of Maybes, filter to keep only the Justs

stripMaybe :: Ord a => S.Set (Maybe a) -> S.Set a

stripMaybe x = S.fromList $ Maybe.catMaybes $ S.toList x

-- Close a set of sorts under a subsort relation

cspSubsortCloseSorts :: CspSign -> S.Set SORT -> S.Set SORT

cspSubsortCloseSorts sig sorts =

S.unions subsort_sets

where subsort_sets = S.toList $ S.map (cspSubsortPreds sig) sorts

-}

-- | CSP process signature.

data CspProcSign = CspProcSign

{ chans :: ChanNameMap

, procs :: ProcNameMap

} deriving (Eq, Show)

-- | A CspCASL signature is a CASL signature with a CSP process

-- signature in the extendedInfo part.

type CspSign = Sign () CspProcSign

-- | Empty CspCASL signature.

emptyCspSign :: CspSign

emptyCspSign = emptySign emptyCspProcSign

-- | Empty CSP process signature.

emptyCspProcSign :: CspProcSign

emptyCspProcSign = CspProcSign

{ chans = Map.empty

, procs = Map.empty

}

-- | Compute union of two CSP process signatures.

addCspProcSig :: CspProcSign -> CspProcSign -> CspProcSign

addCspProcSig a b =

a { chans = chans a `Map.union` chans b

, procs = procs a `Map.union` procs b

}

-- XXX looks incomplete!

isInclusion :: CspProcSign -> CspProcSign -> Bool

isInclusion _ _ = True

-- XXX morphisms between CSP process signatures?

data CspAddMorphism = CspAddMorphism

{ channelMap :: Map.Map Id Id

, processMap :: Map.Map Id Id

} deriving (Eq, Show)

type CspMorphism = Morphism () CspProcSign CspAddMorphism

emptyCspAddMorphism :: CspAddMorphism

emptyCspAddMorphism = CspAddMorphism

{ channelMap = Map.empty -- ???

, processMap = Map.empty

}

-- dummy instances, need to be elaborated!

instance DocUtils.Pretty CspProcSign where

pretty = Doc.text . show

instance DocUtils.Pretty CspAddMorphism where

pretty = Doc.text . show