{- |

Module : $Header$

Copyright : (c) Christian Maeder and Uni Bremen 2003-2005

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

Maintainer : maeder@tzi.de

Stability : experimental

Portability : portable

merging parts of local environment

-}

module HasCASL.Merge where

import Common.Id

import Common.DocUtils

import Common.Result

import HasCASL.As

import HasCASL.Le

import HasCASL.AsUtils

import HasCASL.TypeAna

import HasCASL.PrintLe()

import HasCASL.Unify

import HasCASL.Builtin

import HasCASL.MapTerm

import qualified Data.Map as Map

import qualified Data.Set as Set

import Control.Monad(foldM)

import Data.List

-- | merge together repeated or extended items

class Mergeable a where

merge :: a -> a -> Result a

instance (Ord a, PosItem a, Pretty a, Mergeable b)

=> Mergeable (Map.Map a b) where

merge = mergeMap id merge

improveDiag :: (PosItem a, Pretty a) => a -> Diagnosis -> Diagnosis

improveDiag v d = d { diagString = let f:l = lines $ diagString d in

unlines $ (f ++ " of '" ++ showDoc v "'") : l

, diagPos = getRange v

}

mergeMap :: (Ord a, PosItem a, Pretty a) =>

(b -> b) -> (b -> b -> Result b)

-> Map.Map a b -> Map.Map a b -> Result (Map.Map a b)

mergeMap e f m1 m2 = foldM ( \ m (k, v) ->

case k `Map.lookup` m of

Nothing -> return $ Map.insert k (e v) m

Just w ->

let Result ds mu = f (e v) w

ns = map (improveDiag k) ds

in case mu of

Nothing -> Result ns $ Nothing

Just u -> Result ns $ Just $ Map.insert k u m)

Map.empty (Map.toList m1 ++ Map.toList m2)

instance Mergeable a => Mergeable (Maybe a) where

merge m1 m2 = case m1 of

Nothing -> return m2

Just v1 -> case m2 of

Nothing -> return m1

Just v2 -> do v <- merge v1 v2

return $ Just v

instance Mergeable ClassInfo where

merge = mergeA "super classes"

instance (Pretty a, Eq a) => Mergeable (AnyKind a) where

merge = mergeA "super kinds"

mergeTypeInfo :: TypeInfo -> TypeInfo -> Result TypeInfo

mergeTypeInfo t1 t2 =

do k <- merge (typeKind t1) $ typeKind t2

o <- merge (otherTypeKinds t1) $ otherTypeKinds t2

s <- merge (superTypes t1) $ superTypes t2

d <- mergeTypeDefn (typeDefn t1) $ typeDefn t2

return $ TypeInfo k o s d

mergeTypeDefn :: TypeDefn -> TypeDefn -> Result TypeDefn

mergeTypeDefn d1 d2 =

case (d1, d2) of

(_, DatatypeDefn _) -> return d2

(PreDatatype, _) -> fail "expected data type definition"

(_, PreDatatype) -> return d1

(NoTypeDefn, _) -> return d2

(_, NoTypeDefn) -> return d1

(AliasTypeDefn s1, AliasTypeDefn s2) ->

do s <- mergeAlias s1 s2

return $ AliasTypeDefn s

(_, _) -> mergeA "TypeDefn" d1 d2

instance Mergeable Vars where

merge = mergeA "variables for subtype definition"

mergeAlias :: Type -> Type -> Result Type

mergeAlias s1 s2 = if s1 == s2 then return s1

else fail $ "wrong type" ++ expected s1 s2

instance Mergeable OpAttr where

merge (UnitOpAttr t1 p1) (UnitOpAttr t2 p2) =

do t <- mergeTerm Warning t1 t2

return $ UnitOpAttr t (p1 `appRange` p2)

merge a1 a2 = mergeA "attributes" a1 a2

instance Mergeable OpBrand where

merge b1 b2 = return $ case (b1, b2) of

(Pred, _) -> Pred

(_, Pred) -> Pred

(Op, _) -> Op

(_, Op) -> Op

_ -> Fun

instance Mergeable OpDefn where

merge d1 d2 = case (d1, d2) of

(NoOpDefn b1, NoOpDefn b2) -> do

b <- merge b1 b2

return $ NoOpDefn b

(SelectData c1 s, SelectData c2 _) -> do

c <- merge c1 c2

return $ SelectData c s

(Definition b1 e1, Definition b2 e2) -> do

d <- mergeTerm Hint e1 e2

b <- merge b1 b2

return $ Definition b d

(NoOpDefn b1, Definition b2 e2) -> do

b <- merge b1 b2

return $ Definition b e2

(Definition b1 e1, NoOpDefn b2) -> do

b <- merge b1 b2

return $ Definition b e1

(ConstructData _, SelectData _ _) ->

fail "illegal selector as constructor redefinition"

(SelectData _ _, ConstructData _) ->

fail "illegal constructor as selector redefinition"

(ConstructData _, _) -> return d1

(_, ConstructData _) -> return d2

(SelectData _ _, _) -> return d1

(_, SelectData _ _) -> return d2

instance Eq a => Mergeable [a] where

merge l1 l2 = case l1 of

[] -> return l2

e : l -> do

l3 <- merge l l2

return $ if any (e==) l2 then l3 else e : l3

instance Ord a => Mergeable (Set.Set a) where

merge s1 s2 = return $ Set.union s1 s2

mergeOpInfos :: TypeMap -> OpInfos -> OpInfos -> Result OpInfos

mergeOpInfos tm (OpInfos l1) (OpInfos l2) =

do l <- mergeOps (addUnit tm) l1 l2

return $ OpInfos l

mergeOps :: TypeMap -> [OpInfo] -> [OpInfo] -> Result [OpInfo]

mergeOps _ [] l = return l

mergeOps tm (o:os) l2 = do

let (es, us) = partition (isUnifiable tm 1

(opType o) . opType) l2

l1 <- mergeOps tm os us

if null es then return (o : l1)

else do r <- mergeOpInfo tm o $ head es

return (r : l1)

mergeOpInfo :: TypeMap -> OpInfo -> OpInfo -> Result OpInfo

mergeOpInfo tm o1 o2 =

do let s1 = opType o1

s2 = opType o2

sc <- if instScheme tm 1 s2 s1 then return s1

else if instScheme tm 1 s1 s2 then return s2

else fail "overlapping but incompatible type schemes"

as <- merge (opAttrs o1) $ opAttrs o2

d <- merge (opDefn o1) $ opDefn o2

return $ OpInfo sc as d

instance Mergeable Env where

merge e1 e2 =

do cMap <- merge (classMap e1) $ classMap e2

tMap <- mergeMap id mergeTypeInfo

(typeMap e1) $ typeMap e2

case filterAliases tMap of

tAs -> do

as <- mergeMap (OpInfos .

map (mapOpInfo (id, expandAliases tAs)) . opInfos)

(mergeOpInfos tMap)

(assumps e1) $ assumps e2

return initialEnv { classMap = cMap

, typeMap = tMap

, assumps = as }

mergeA :: (Pretty a, Eq a) => String -> a -> a -> Result a

mergeA str t1 t2 = if t1 == t2 then return t1 else

fail ("different " ++ str ++ expected t1 t2)

mergeTerm :: DiagKind -> Term -> Term -> Result Term

mergeTerm k t1 t2 = if t1 == t2 then return t1 else

Result [Diag k ("different terms" ++ expected t1 t2)

nullRange] $ Just t2