{- |

Module : $Header$

Description : Signatures of COL as extension of CASL signatures

Copyright : (c) Till Mossakowski, C. Maeder, Uni Bremen 2004

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

Maintainer : till@informatik.uni-bremen.de

Stability : provisional

Portability : portable

Signatures of COL as extension of CASL signatures.

-}

module COL.COLSign where

import qualified Data.Set as Set

import qualified Data.Map as Map

import Common.Id

data COLSign = COLSign { constructors :: Set.Set Id

, observers :: Map.Map Id Int

} deriving (Show, Eq)

emptyCOLSign :: COLSign

emptyCOLSign = COLSign Set.empty Map.empty

addCOLSign :: COLSign -> COLSign -> COLSign

addCOLSign s1 s2 =

s1 { constructors = Set.union (constructors s1) $ constructors s2

, observers = Map.union (observers s1) $ observers s2 }

diffCOLSign :: COLSign -> COLSign -> COLSign

diffCOLSign s1 s2 =

s1 { constructors = Set.difference (constructors s1) $ constructors s2

, observers = Map.difference (observers s1) $ observers s2 }

isSubCOLSign :: COLSign -> COLSign -> Bool

isSubCOLSign s1 s2 =

Set.null (constructors s2 Set.\\ constructors s1)

&& Map.null (observers s2 Map.\\ observers s1)