{- |

Module : ./CASL/Cycle.hs

Description : removing sort cycles

Copyright : (c) Christian Maeder, DFKI GmbH 2013

License : GPLv2 or higher, see LICENSE.txt

Maintainer : Christian.Maeder@dfki.de

Stability : provisional

Portability : portable

removing sort cycles

-}

module CASL.Cycle where

import CASL.Sign

import CASL.Morphism

import qualified Data.Map as Map

import qualified Data.Set as Set

import qualified Common.Lib.MapSet as MapSet

import qualified Common.Lib.Rel as Rel

removeSortCycles :: Sign f e -> (Sign f e, Sort_map)

removeSortCycles sign = let

rel = sortRel sign

cs = Rel.sccOfClosure rel

mc = foldr ((\ (a, s) m -> Set.fold (`Map.insert` a) m s)

. Set.deleteFindMin) Map.empty cs

in (sign

{ sortRel = Rel.irreflex $ Rel.collaps cs rel

, emptySortSet = Set.map (mapSort mc) $ emptySortSet sign

, opMap = MapSet.map (mapOpType mc) $ opMap sign

, predMap = MapSet.map (mapPredType mc) $ predMap sign

}, mc)