{- |

Module : $Header$

Description : Morphisms for Maude

Copyright : (c) Martin Kuehl, Uni Bremen 2008-2009

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

Maintainer : mkhl@informatik.uni-bremen.de

Stability : experimental

Portability : portable

Definition of morphisms for Maude.

-}

module Maude.Morphism (

Morphism(..),

SortMap,

OpMap,

-- fromSignRenamings,

-- applyRenamings,

-- fromSignsRenamings,

symbolMap,

empty,

identity,

isIdentity,

inclusion,

inverse,

compose,

isLegal,

isInclusion,

mapSentence,

renameSorts,

union,

setTarget,

-- extendMorphismSorts,

-- extendWithSortRenaming,

) where

-- import Maude.AS_Maude

import Maude.Symbol

import Maude.Meta

import Maude.Util

import Maude.Printing ()

import Maude.Sign (Sign)

import Maude.Sentence (Sentence)

import qualified Maude.Sign as Sign

import qualified Maude.Sentence as Sen

import qualified Data.Set as Set

import qualified Data.Map as Map

import Common.Result (Result)

import qualified Common.Result as Result

import Common.Doc hiding (empty)

import Common.DocUtils (Pretty(..))

type SortMap = SymbolMap

type OpMap = SymbolMap

type LabelMap = SymbolMap

data Morphism = Morphism {

source :: Sign,

target :: Sign,

sortMap :: SortMap,

opMap :: OpMap,

labelMap :: LabelMap

} deriving (Show, Ord, Eq)

instance Pretty Morphism where

pretty mor = let

pr'pair txt left right = hsep

[txt, pretty left, text "to", pretty right]

pr'ops src tgt = pr'pair (text "op") src (getName tgt)

pr'map fun = vsep . map (uncurry fun) . Map.toList

smap = pr'map (pr'pair $ text "sort") $ sortMap mor

omap = pr'map pr'ops $ opMap mor

lmap = pr'map (pr'pair $ text "label") $ labelMap mor

in vsep [ smap, omap, lmap ]

-- text "\n\nTarget:" <$$> pretty $ target mor

-- -- | create a Morphism from an initial signature and a list of Renamings

-- fromSignRenamings :: Sign -> [Renaming] -> Morphism

-- fromSignRenamings sg rnms = applyRenamings (createInclMorph sg sg) rnms

--

-- applyRenamings :: Morphism -> [Renaming] -> Morphism

-- applyRenamings m rnms = foldr applyRenaming2 (foldr applyRenaming1 m rnms) rnms

--

-- -- | Rename the signature with the operator renaming and creates a morphism

-- -- with only the operator map. Sort renamings have to be applied to this

-- -- morphism.

-- applyRenaming1 :: Renaming -> Morphism -> Morphism

-- applyRenaming1 rnm mor = let

-- tgt = target mor

-- omap = opMap mor

-- in case rnm of

-- OpRenaming1 from (To to ats) -> let

-- a = getName from

-- b = getName to

-- in mor {

-- target = Sign.renameOp a b ats tgt,

-- opMap = allProfilesRenaming a b tgt omap

-- }

-- OpRenaming2 from ar co (To to ats) -> let

-- a = getName from

-- b = getName to

-- ar' = map getName ar

-- co' = getName co

-- p = (ar', co')

-- in mor {

-- target = Sign.renameOpProfile a ar' b ats tgt,

-- opMap = Map.insertWith (Map.union) a (Map.insert p (b, p) Map.empty) omap

-- }

-- _ -> mor

--

-- -- | Rename a signature with the sort and label renamings, and modify

-- -- the given morphism by renaming the sorts in the profiles.

-- applyRenaming2 :: Renaming -> Morphism -> Morphism

-- applyRenaming2 rnm mor = let

-- tgt = target mor

-- smap = sortMap mor

-- omap = opMap mor

-- lmap = labelMap mor

-- in case rnm of

-- SortRenaming from to -> let

-- a = getName from

-- b = getName to

-- in mor {

-- target = Sign.renameSort a b tgt,

-- sortMap = Map.insert a b smap,

-- opMap = renameSortOpMap a b omap

-- }

-- LabelRenaming from to -> let

-- a = getName from

-- b = getName to

-- in mor {

-- target = Sign.renameLabel a b tgt,

-- labelMap = Map.insert a b lmap

-- }

-- _ -> mor

-- | Rename sorts in the profiles of an operator map.

renameSortOpMap :: Symbol -> Symbol -> OpMap -> OpMap

renameSortOpMap from to = Map.map $ mapSorts $ Map.singleton from to

-- allProfilesRenaming :: Qid -> Qid -> Sign -> OpMap -> OpMap

-- allProfilesRenaming from to sg om = om'

-- where om_sg = Sign.ops sg

-- om' = if Map.member from om_sg

-- then Map.insert from (allProfilesRenamingAux to $ fromJust $ Map.lookup from om_sg) om

-- else om

--

-- allProfilesRenamingAux :: Qid -> Sign.OpDeclSet -> Map.Map Profile (Qid, Profile)

-- allProfilesRenamingAux q = Set.fold (f q) Map.empty

-- where f = \ to (x, y, _) m -> Map.insert (x, y) (to, (x, y)) m

-- -- | create a Morphism from the initial signatures and a list of Renamings

-- fromSignsRenamings :: Sign -> Sign -> [Renaming] -> Morphism

-- fromSignsRenamings sg1 sg2 rnms = foldr insertRenaming2 (foldr insertRenaming1 m rnms) rnms

-- where m = createInclMorph sg1 sg2

--

-- -- | insert a Renaming into a Morphism

-- insertRenaming1 :: Renaming -> Morphism -> Morphism

-- insertRenaming1 rename mor = let

-- tgt = target mor

-- omap = opMap mor

-- in case rename of

-- OpRenaming1 from (To to _) -> let

-- a = getName from

-- b = getName to

-- in mor {

-- opMap = allProfilesRenaming a b tgt omap

-- }

-- OpRenaming2 from ar co (To to _) -> let

-- a = getName from

-- b = getName to

-- ar' = map getName ar

-- co' = getName co

-- p = (ar', co')

-- in mor {

-- opMap = Map.insertWith (Map.union) a (Map.insert p (b, p) Map.empty) omap

-- }

-- _ -> mor

--

-- insertRenaming2 :: Renaming -> Morphism -> Morphism

-- insertRenaming2 rename mor = let

-- smap = sortMap mor

-- omap = opMap mor

-- lmap = labelMap mor

-- in case rename of

-- SortRenaming from to -> let

-- a = getName from

-- b = getName to

-- in mor {

-- sortMap = Map.insert a b smap,

-- opMap = renameSortOpMap a b omap

-- }

-- LabelRenaming from to -> let

-- a = getName from

-- b = getName to

-- in mor {

-- labelMap = Map.insert a b lmap

-- }

-- _ -> mor

-- | extract the SymbolMap of a Morphism

symbolMap :: Morphism -> SymbolMap

symbolMap mor = Map.unions [sortMap mor, opMap mor, labelMap mor]

-- | the empty Morphism

empty :: Morphism

empty = identity Sign.empty

-- | the identity Morphism

identity :: Sign -> Morphism

identity sign = inclusion sign sign

-- | the inclusion Morphism

inclusion :: Sign -> Sign -> Morphism

inclusion src tgt = Morphism {

source = src,

target = tgt,

sortMap = Map.empty,

opMap = Map.empty,

labelMap = Map.empty

}

-- | the inverse Morphism

inverse :: Morphism -> Result Morphism

inverse mor = let

invertMap = Map.foldWithKey (flip Map.insert) Map.empty

in return Morphism {

source = target mor,

target = source mor,

sortMap = invertMap $ sortMap mor,

opMap = invertMap $ opMap mor,

labelMap = invertMap $ labelMap mor

}

-- | the composition of two Morphisms

compose :: Morphism -> Morphism -> Result Morphism

compose f g

| target f /= source g = fail

"target of the first and source of the second morphism are different"

| otherwise = let

-- map'map takes:

-- mp :: Morphism -> SymbolMap

-- and returns a function |Symbol -> Symbol| by treating

-- each SymbolMap as a function and then combining them

map'map mp = mapAsFunction (mp g) . mapAsFunction (mp f)

-- insert takes:

-- mp :: Morphism -> SymbolMap

-- x :: Symbol

-- and returns a function |SymbolMap -> SymbolMap| by

-- applying both SymbolMaps (from |f| and |g|) to |x|, then

-- inserting the resulting renaming into the SymbolMap if

-- there is one and just leaving it (the SymbolMap) alone

-- otherwise.

insert mp x = let y = map'map mp x

in if x == y then id else Map.insert x y

-- compose'map takes:

-- mp :: Morphism -> SymbolMap

-- items :: Sign -> SymbolSet

-- and constructs a combined SymbolMap from both our Morphisms

compose'map mp items = if Map.null (mp g)

-- if the SymbolMap of |g| is empty, we use the one from |f|

then mp f

-- otherwise we start with the SymbolSet from |source f|

-- and construct a combined SymbolMap by applying both

-- SymbolMaps (from |f| and |g|) to each item in |insert|

else Set.fold (insert mp) Map.empty $ items (source f)

-- We want a morphism from |source f| to |target g|,

in return (inclusion (source f) $ target g) {

sortMap = compose'map sortMap getSorts -- ,

-- opMap = compose'map opMap getOps -- ,

-- labelMap = compose'map labelMap getLabels

}

-- | check that a Morphism is legal

isLegal :: Morphism -> Bool

isLegal mor = let

src = source mor

tgt = target mor

smap = sortMap mor

omap = opMap mor

lmap = labelMap mor

subset mp items = let mapped = Set.map $ mapAsFunction mp

in Set.isSubsetOf (mapped $ items src) $ items tgt

lg'source = Sign.isLegal src

lg'sortMap = subset smap getSorts

lg'opMap = subset omap getOps

lg'labelMap = subset lmap getLabels

lg'target = Sign.isLegal tgt

in all id [lg'source, lg'sortMap, lg'opMap, lg'labelMap, lg'target]

-- | check that a Morphism is the identity

isIdentity :: Morphism -> Bool

isIdentity mor = source mor == target mor

-- | check that a Morphism is an Inclusion

isInclusion :: Morphism -> Bool

isInclusion mor = let

null'sortMap = Map.null (sortMap mor)

null'opMap = Map.null (opMap mor)

null'labelMap = Map.null (labelMap mor)

in all id [null'sortMap, null'opMap, null'labelMap]

-- | translate a Sentence along a Morphism

mapSentence :: Morphism -> Sentence -> Result Sentence

mapSentence mor = let

smap = mapSorts (sortMap mor)

omap = mapOps (opMap mor)

lmap = mapLabels (labelMap mor)

in return . lmap . omap . smap

union :: Morphism -> Morphism -> Morphism

union m1 m2 = let apply func items = func (items m1) (items m2)

in Morphism {

source = apply Sign.union source,

target = apply Sign.union target,

sortMap = apply Map.union sortMap,

opMap = apply Map.union opMap,

labelMap = apply Map.union labelMap

}

setTarget :: Sign -> Morphism -> Morphism

setTarget sign morph = morph {target = sign}

renameSorts :: Morphism -> Symbols -> Symbols

renameSorts = mapSorts . sortMap

-- extendMorphismSorts :: Morphism -> Qid -> [Qid] -> Morphism

-- extendMorphismSorts mor sym syms = let

-- tgt = target mor

-- smap = sortMap mor

-- in mor {

-- target = Sign.renameListSort (createRenaming sym syms) tgt,

-- sortMap = extendSortMap sym syms smap

-- }

-- createRenaming :: Qid -> [Qid] -> [(Qid, Qid)]

-- createRenaming _ [] = []

-- createRenaming sym (sym' : syms) = (sym', new_sym) : createRenaming sym syms

-- where new_sym = mkSimpleId $ show sym ++ "$" ++ show sym'

-- extendSortMap :: Qid -> [Qid] -> QidMap -> QidMap

-- extendSortMap _ [] sm = sm

-- extendSortMap sym (sym' : syms) sort_map = extendSortMap sym syms sort_map'

-- where new_sym = mkSimpleId $ show sym ++ "$" ++ show sym'

-- sort_map' = Map.fromList $ extendSortList sym' new_sym $ Map.toList sort_map

-- extendSortList :: Qid -> Qid -> [(Qid, Qid)] -> [(Qid, Qid)]

-- extendSortList from to [] = [(from, to)]

-- extendSortList from to (s@(sym1, sym2) : syms) = if from == sym2

-- then (sym1, to) : syms

-- else s : extendSortList from to syms

-- extendWithSortRenaming :: Qid -> Qid -> Morphism -> Morphism

-- extendWithSortRenaming from to mor = let

-- tgt = target mor

-- smap = sortMap mor

-- omap = opMap mor

-- in mor {

-- target = Sign.renameSort from to tgt,

-- sortMap = Map.insert from to smap,

-- opMap = renameSortOpMap from to omap

-- }

-- | TODO :

-- - compose with the new OpMap

-- - isLegal with the new OpMap

-- - mapSentence with the new OpMap