EPRelation.hs revision cb12647c82658c6500b0c5564f3c111264a95352
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann{-# LANGUAGE TypeSynonymInstances #-}
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann{- |
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannModule : $Header$
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannDescription : Handling of extended parameter relations
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannCopyright : (c) Ewaryst Schulz, DFKI Bremen 2010
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannLicense : GPLv2 or higher, see LICENSE.txt
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannMaintainer : ewaryst.schulz@dfki.de
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannStability : experimental
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannPortability : non-portable
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannThis module defines an ordering on extended parameters and provides analysis tools.
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann -}
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannmodule CSL.EPRelation where
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Control.Monad.Trans
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Control.Monad.Reader
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport qualified Data.Map as Map
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport qualified Data.Set as Set
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Data.Char
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Data.List
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Data.Maybe
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Data.Tree
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Data.Traversable (fmapDefault)
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport CSL.EPBasic
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport CSL.SMTComparison
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport CSL.TreePO
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport CSL.AS_BASIC_CSL
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport CSL.ExtendedParameter
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Common.Id (tokStr)
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Common.Doc
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmannimport Common.DocUtils
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann-- ----------------------------------------------------------------------
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann-- * Datatypes for efficient Extended Parameter comparison
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann-- ----------------------------------------------------------------------
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann-- | A more efficient representation of a list of extended parameters,
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann-- particularly for comparison
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmanntype EPExps = Map.Map String EPExp
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannevalEPs :: (String -> Int) -> EPExps -> Bool
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannevalEPs f eps = Map.foldWithKey g True eps where
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann g k v b = evalEP (f k) v && b
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannprettyEPs :: EPExps -> Doc
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannprettyEPs eps
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann | Map.null eps = text "*"
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann | otherwise = brackets $ sepByCommas $ map (text . showEP) $ Map.toList eps
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannshowEPs :: EPExps -> String
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannshowEPs = show . prettyEPs
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann-- | A star expression is the unconstrained expression corresponding to the
2450a4210dee64b064499a3a1154129bdfc74981Daniel Hausmann-- whole space of extended parameter values
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannisStarEP :: EPExps -> Bool
2450a4210dee64b064499a3a1154129bdfc74981Daniel HausmannisStarEP = Map.null
-- | 'isStarEP' lifted for Range expressions.
isStarRange :: EPRange -> Bool
isStarRange (Atom e) = isStarEP e
isStarRange _ = False
-- | The star range.
starRange :: EPRange
starRange = Atom Map.empty
-- | Conversion function into the more efficient representation.
toEPExps :: [EXTPARAM] -> EPExps
toEPExps = Map.fromList . mapMaybe toEPExp
-- | Sets representing the Parameters for which there is a propagation break
-- (filtered) and for which there is a constraint (constrained)
filteredConstrainedParams :: [EXTPARAM] -> (Set.Set String, Set.Set String)
filteredConstrainedParams = foldl f (Set.empty, Set.empty)
where f (fs, cs) (EP t "-|" _) = (Set.insert (tokStr t) fs, cs)
f (fs, cs) (EP t _ _) = (fs, Set.insert (tokStr t) cs)
{-| This type represents the domain of the extended parameters. It can have
0 entries = no restriction
1 entry = opened rectangle, at least one parameter is one sided restricted
2 entries = probably closed rectangle, at least one parameter is restricted
from both sides
The domain is the intersection of both entries (if there are two)
The domain is important for building partitions, because the partitions are
defined only on the domain, not on the unrestricted space.
-}
type EPDomain = [EPExps]
data EPRange = Union [EPRange] | Intersection [EPRange]
| Complement EPRange | Atom EPExps | Empty
-- | In some cases 'EPRange' can be translated back to 'EPExps'
tryDowncast :: EPRange -> Maybe EPExps
tryDowncast (Complement (Atom x)) =
if Map.size x == 1 then Just $ Map.map complementEP x else Nothing
tryDowncast (Atom x) = Just x
tryDowncast _ = Nothing
evalRange :: (String -> Int) -> EPRange -> Bool
evalRange f re =
case re of
Complement r -> not $ evalRange f r
Union l -> or $ map (evalRange f) l
Intersection l -> and $ map (evalRange f) l
Empty -> False
Atom eps -> evalEPs f eps
-- | A diagnostic output for 'EPRange' which highlights problems in the
-- internal representation
diagnoseEPRange :: EPRange -> Doc
diagnoseEPRange re =
let asIfx s l = parens $ fsep $ punctuate (text s) $ map diagnoseEPRange l
diag s re' = text "DIAG" <>
(parens $ text s <> comma <+> diagnoseEPRange re')
in case re of
Union [] -> diag "EmptyUnion" Empty
Union [x] -> diag "SingletonUnion" x
Union l -> asIfx [' ', chr 8746] l
Intersection [] -> diag "EmptyIntersection" Empty
Intersection [x] -> diag "SingletonIntersection" x
Intersection [x, Complement r] -> asIfx [' ', chr 8726] [x,r]
Intersection l -> asIfx [' ', chr 8745] l
Complement r -> text [chr 8705] <> diagnoseEPRange r
Empty -> text [chr 8709]
Atom eps -> prettyEPs eps
-- | Pretty output for 'EPRange'
prettyEPRange :: EPRange -> Doc
prettyEPRange re =
let f s a b = parens $ hsep [prettyEPRange a, text s, prettyEPRange b]
g s l = parens $ hsep $ text s : map prettyEPRange l
in case re of
Union [r1, r2] -> f "Un" r1 r2
Intersection [r1, r2] -> f "In" r1 r2
Complement r -> g "C" [r]
Union l -> g "Union" l
Intersection l -> g "Intersection" l
Empty -> text "Empty"
Atom eps -> prettyEPs eps
mkUnion :: [EPRange] -> EPRange
mkUnion [] = error "mkUnion: empty list"
mkUnion [x] = x
mkUnion l = Union l
mkIntersection :: [EPRange] -> EPRange
mkIntersection [] = error "mkIntersection: empty list"
mkIntersection [x] = x
mkIntersection l = Intersection l
showEPRange :: EPRange -> String
showEPRange = show . prettyEPRange
instance Show EPRange where
show = showEPRange
instance Pretty EPRange where
pretty = prettyEPRange
-- | Behaves as a map on the list of leafs of the range expression
-- (from left to right)
mapRangeLeafs :: (EPExps -> b) -> EPRange -> [b]
mapRangeLeafs f re =
case re of
Union l -> g l
Intersection l -> g l
Complement r -> mapRangeLeafs f r
Atom eps -> [f eps]
Empty -> []
where g = concatMap (mapRangeLeafs f)
-- | Maps an EP expression transformer over the given range expression
mapRange :: (EPExps -> EPExps) -> EPRange -> EPRange
mapRange f re =
case re of
Union l -> Union $ g l
Intersection l -> Intersection $ g l
Complement r -> Complement $ mapRange f r
Atom eps -> Atom $ f eps
_ -> re
where g = map (mapRange f)
class RangeUtils a where
rangeNames :: a -> Set.Set String
instance RangeUtils EPExps where
rangeNames = Map.keysSet
instance RangeUtils EPRange where
rangeNames = Set.unions . mapRangeLeafs rangeNames
namesInList :: RangeUtils a => [a] -> Set.Set String
namesInList = Set.unions . map rangeNames
{- |
(1) If the arguments are disjoint -> 'Nothing'
(2) If all extended parameter constraints from the first argument are
subsumed by the second argument -> second argument with deleted entries for
these extended parameters
(3) Otherwise -> error: the first argument must be subsumed by or disjoint
with the second one.
-}
projectEPs :: EPExps -> EPExps -> Maybe EPExps
projectEPs e1 e2
| isStarEP e1 = Just e2
| otherwise =
-- take first element from e1 delete it from e1 and proceed with it
let ((k, v), e1') = Map.deleteFindMin e1
e2' = Map.delete k e2
in case Map.lookup k e2 of
Nothing -> projectEPs e1' e2
Just v2 ->
case compareEP v v2 of
Incomparable Disjoint -> Nothing
Comparable x -> if x /= GT then projectEPs e1' e2'
else error $ "projectEPs: e1 > e2 "
++ show (e1,e2)
_ -> error $ "projectEPs: overlap " ++ show (e1,e2)
{- |
Given a range predicate, e.g, A x y z (here with three extended
parameters), we instantiate it partially with the given
instantiation, e.g., x=1, and obtain A 1 y z. The new predicate
does not depend on x anymore and can be built by replacing all
atomic subexpressions in A which talk about x
(1) by the subexpression
where the constraint for x is removed if the given instantiation
satisfies this subexpression (e.g., x<10) or
(2) by 'Empty' if this
constraint is not satisfied (e.g., x>1)
-}
projectRange :: EPExps -> EPRange -> EPRange
projectRange e re = simplifyRange $ f re
where f rexp =
case rexp of
Union l -> Union $ map f l
Intersection l -> Intersection $ map f l
Complement r -> Complement $ f r
Atom eps -> case projectEPs e eps of
Nothing -> Empty
Just eps' -> Atom eps'
Empty -> Empty
{- | Removes all star- and empty-entries from inside of the range expression.
Union [,*,] -> * (top element)
Intersection [,*,] -> Intersection [,] (neutral element)
Complement * -> Empty (bottom element)
For Empty its the dual behaviour
-}
simplifyRange :: EPRange -> EPRange
simplifyRange re =
case tryDowncast re of
Just eps -> Atom eps
_ ->
case re of
Union l -> f [] l
Intersection l -> g [] l
Complement r ->
case simplifyRange r of
Empty -> starRange
r' | isStarRange r' -> Empty
| otherwise -> Complement r'
_ -> re
where -- returns either a simplified list or a new expression
f acc [] = if null acc then Empty else mkUnion acc
f acc (r:l) =
case simplifyRange r of
Empty -> f acc l
r' | isStarRange r' -> r'
| otherwise -> f (acc++[r']) l
g acc [] = if null acc then starRange else mkIntersection acc
g acc (r:l) =
case simplifyRange r of
Empty -> Empty
r' | isStarRange r' -> g acc l
| otherwise -> g (acc++[r']) l
-- ----------------------------------------------------------------------
-- * Models for 'EPRange' expressions
-- ----------------------------------------------------------------------
data Model a = Model [(Int, Int)] (Map.Map [Int] a)
boolModelChar :: Bool -> Char
boolModelChar b = if b then '*' else ' '
modelToString :: (a -> Char) -> Model a -> String
modelToString f (Model l vm) =
case l of
[(a, b)] -> map (f . (\ x -> Map.findWithDefault (error $ "modelToString: elem not in map " ++ show x ++ "\n" ++ (show $ Map.keys vm)) x vm) . (:[])) [a..b] ++ "\n"
[(a, b), (c, d)] ->
let g y = map (f . (vm Map.!)) [[x, y]| x <- [a..b]]
in unlines $ map g [c..d]
[] -> ""
_ -> concat ["Cannot output a ", show $ length l, "-dim model"]
modelOf :: Map.Map String (Int, Int) -> EPRange -> Model Bool
modelOf rm re = let
f l s = l !! (Map.findIndex s rm)
g (a, b) l = [x : y | y <- l, x <- [a..b]]
inpl = Map.fold g [[]] rm
h x = (x, evalRange (f x) re)
in Model (Map.elems rm) $ Map.fromList $ map h inpl
-- ----------------------------------------------------------------------
-- * Extended Parameter comparison
-- ----------------------------------------------------------------------
{- | Compares two 'EPExps': They are pairwise compared over the common
extended parameter names (see also the operator-table in combineCmp).
This function can be optimized in returning directly disjoint
once a disjoint subresult encountered.
-}
compareEPs :: EPExps -> EPExps -> EPCompare
compareEPs eps1 eps2 =
-- choose smaller map for fold, and remember if maps are swapped
let (eps, eps', sw) = if Map.size eps1 > Map.size eps2
then (eps2, eps1, True) else (eps1, eps2, False)
-- foldfunction
f k ep (b, c) = let (cmp', c') =
case Map.lookup k eps' of
-- increment the counter
Just ep' -> (compareEP ep ep', c+1)
-- if key not present in reference map then
-- ep < *
_ -> (Comparable LT, c)
in (combineCmp b cmp', c')
-- we fold over the smaller map, which can be more efficient.
-- We have to count the number of matched parameter names to see if
-- there are still EPs in eps' which indicates to compare with ">" at
-- the end of the fold.
(epc, cnt) = Map.foldWithKey f
(Comparable EQ, 0) -- start the fold with "=",
-- the identity element
eps -- the smaller map
epc' = if Map.size eps' > cnt
then combineCmp (Comparable GT) epc else epc
-- if the maps were swapped then swap the result
in if sw then swapCmp epc' else epc'
{-
we need to take into account the global constraints on the range of the
extended parameters, e.g., I in [1,5] or I>=0...
This complicates the simple comparison and we postpone it for the moment.
-- | We try to decide the relation between the given ranges without using
-- an external decision procedure.
trySimpleFullCmp :: EPRange -> EPRange -> Maybe (EPCompare, Bool, Bool)
trySimpleFullCmp r1 r2
| isStarRange r1 && r1 == r2 = Just (Comparable EQ, False, False)
| r1 == Empty && r1 == r2 = Just (Comparable EQ, True, True)
| otherwise =
case map tryDowncast [r1, r2] of
[Just eps1, Just eps2] -> Just (compareEPs eps1 eps2, False, False)
_ -> Nothing
-- | Same as 'trySimpleFullCmp' but without deciding if the ranges are empty or not
trySimpleCmp :: EPRange -> EPRange -> Maybe (EPCompare, Bool, Bool)
trySimpleCmp r1 r2
| isStarRange r1 = Just (Comparable GT, False, r2 == Empty)
| isStarRange r2 = Just (Comparable LT, r1 == Empty, False)
-}
-- ----------------------------------------------------------------------
-- * SMT based comparison - utility functions
-- ----------------------------------------------------------------------
-- | Builds a Boolean representation from the extended parameter expression.
-- Variable names are composed from the string "x" together with an integer.
boolExps :: VarMap -> EPExps -> BoolRep
boolExps m eps | isStarEP eps = trueBool
| otherwise = And $ map f $ Map.assocs eps where
err = error "boolExps: No matching"
f (k, v) = toBoolRep ("x" ++ show (Map.findWithDefault err k m)) v
boolRange :: VarMap -> EPRange -> BoolRep
boolRange m (Union l) = Or $ map (boolRange m) l
boolRange m (Intersection l) = And $ map (boolRange m) l
boolRange m (Complement a) = Not $ boolRange m a
boolRange m (Atom eps) = boolExps m eps
boolRange _ Empty = falseBool
-- ----------------------------------------------------------------------
-- * Trees to store Extended Parameter indexed values
-- ----------------------------------------------------------------------
{- | We use trees with special labels of this type.
In two assignments of the same constant we don't allow the
extended parameter part to overlap. Hence we can store the
definiens of assignments in a tree indexed by the extended
parameters. The labels of the tree contain the extended parameter
and an arbitrary value and all elements in the subforest have a
label with an extended parameter lower than the extended
parameter at the root node.
-}
data EPNodeLabel a = EPNL { eplabel :: EPExps
, nodelabel :: a }
type EPTree a = Tree (EPNodeLabel a)
type EPForest a = Forest (EPNodeLabel a)
makeEPLeaf :: a -> EPExps -> EPTree a
makeEPLeaf x eps = Node { rootLabel = EPNL { eplabel = eps, nodelabel = x }
, subForest = [] }
-- | Inserts a node to an 'EPForest'. We need to check if the new node subsumes
-- a nonempty subset of the given forrest.
insertEPNodeToForest :: EPTree a -- ^ Node to insert, assumed to have an
-- empty subforest (the subforest is ignored)
-> EPForest a -- ^ Forest to insert the given node in
-> EPForest a -- ^ Resulting forest
insertEPNodeToForest n [] = [n]
insertEPNodeToForest n ft@(t:rft) =
if null ssf then
case insertEPNode n t of
Just t' -> t': rft
Nothing -> t : insertEPNodeToForest n rft
else n{subForest = ssf}:nssf
where (ssf, nssf) = getSubsumedForest (eplabel $ rootLabel n) ft
-- | Splits the given forest to a by the 'EPExps' subsumed part and a not
-- subsumed part. Errors are reported in situations which would lead to invalid
-- forests when used in the 'insertEPNodeToForest'-method.
getSubsumedForest :: EPExps -- ^ Expression to be checked against the forest
-> EPForest a -- ^ Forest to be checked for being subsumed
-> (EPForest a, EPForest a) -- ^ Subsumed forest and the rest
getSubsumedForest eps ft = partition p ft where
ep2 = eplabel . rootLabel
p t = case compareEPs eps (ep2 t) of
Comparable EQ ->
error $ concat [ "getSubsumedForest: equality "
, "overlap ", show $ prettyEPs eps, " = "
, show $ prettyEPs (ep2 t) ]
Incomparable Overlap ->
error $ concat [ "getSubsumedForest: overlap "
, show $ prettyEPs eps, " = "
, show $ prettyEPs (ep2 t) ]
Comparable GT -> True
_ -> False
-- | Inserts a node to an 'EPTree' and if the nodes are disjoint
-- 'Nothing' is returned. Both insert methods return an error if an
-- overlapping occurs.
insertEPNode :: EPTree a -- ^ Node to insert
-> EPTree a -- ^ Tree to insert the given node in
-> Maybe (EPTree a) -- ^ Resulting tree
insertEPNode n t =
case compareEPs ep1 ep2 of
Comparable EQ -> error $ concat [ "insertEPNode: equality overlap "
, show ep1, " = ", show ep2 ]
Incomparable Overlap -> error $ concat [ "insertEPNode: overlap "
, show ep1, " = ", show ep2 ]
Incomparable Disjoint -> Nothing
Comparable GT -> aInB t n
Comparable LT -> aInB n t
where
aInB a b = Just b { subForest = insertEPNodeToForest a (subForest b) }
ep1 = eplabel $ rootLabel n
ep2 = eplabel $ rootLabel t
-- | Returns a graphical representation of the forest.
showEPForest :: (a -> String) -> EPForest a -> String
showEPForest pr =
let f lbl = showEPs (eplabel lbl)
++ case pr $ nodelabel lbl of
[] -> []
x -> ": " ++ x
in drawForest . (map $ fmapDefault f)
-- | This function is not a simple map, but inserts the nodes correctly
-- to the tree.
forestFromEPsGen :: (a -> EPTree b) -> [a] -> EPForest b
forestFromEPsGen f l = foldr (insertEPNodeToForest . f) [] l
-- | This function is not a simple map, but inserts the nodes correctly
-- to the tree.
forestFromEPs :: (a -> (b, EPExps)) -> [a] -> EPForest b
forestFromEPs f = forestFromEPsGen $ uncurry makeEPLeaf . f
instance Pretty a => Pretty (EPNodeLabel a) where
pretty x = parens $ prettyEPs (eplabel x) <> colon <+> pretty (nodelabel x)
instance Pretty a => Show (EPNodeLabel a) where
show = show . pretty
-- ----------------------------------------------------------------------
-- * Partitions based on 'EPRange'
-- ----------------------------------------------------------------------
class MonadIO m => CompareIO m where
rangeFullCmp :: EPRange -> EPRange -> m (EPCompare, Bool, Bool)
logMessage :: String -> m ()
logMessage _ = return ()
rangeCmp :: CompareIO m => EPRange -> EPRange -> m EPCompare
rangeCmp x y = liftM tripleFst $ rangeFullCmp x y
type SmtComparer = ReaderT VarEnv IO
execSMTComparer :: VarEnv -> SmtComparer a -> IO a
execSMTComparer ve smt = runReaderT smt ve
instance CompareIO SmtComparer where
logMessage = liftIO . putStrLn
rangeFullCmp r1 r2 = do
ve <- ask
let vm = varmap ve
lift $ smtCompare ve (boolRange vm r1) $ boolRange vm r2
data Partition a = AllPartition a | Partition [(EPRange, a)]
instance Show a => Show (Partition a) where
show p = show $ prettyPartition (text . show) p
prettyPartition :: (a -> Doc) -> Partition a -> Doc
prettyPartition f (AllPartition x) = braces $ braces $ f x
prettyPartition f (Partition l) = braces $ sepByCommas $ map (braces . g) l
where g (r, x) = f x <+> text "|" <+> prettyEPRange r
instance Pretty a => Pretty (Partition a) where
pretty (AllPartition x) = text "AllPartition:" <+> pretty x
pretty (Partition l) = text "Partition:" <+>
ppPairlist pretty pretty braces vcat f l
where f a b = parens $ a <+> text "|" <+> b
instance Functor Partition where
fmap f (AllPartition x) = AllPartition $ f x
fmap f (Partition l) = Partition $ map g l
where g (er, x) = (er, f x)
{- | Two partitions are refined to a result partition which is finer than each
of the input partitions.
The annotations of the new partition are as follows:
a set @x@ in the new partition gets the annotation @(a,b)@ where @x'@ comes
from the first partition and is annotated with @a@ and @x''@ comes
from the second partition and is annotated with @b@ and @x@ is a subset of
both, @x'@ and @x''@.
-}
refinePartition :: (CompareIO m, Pretty a, Pretty b) => Partition a
-> Partition b -> m (Partition (a,b))
refinePartition (AllPartition x) pb = return $ fmap ((,) x) pb
refinePartition pa (AllPartition x) = return $ fmap (flip (,) x) pa
refinePartition (Partition l) (Partition l') =
liftM (Partition . concat) $ mapM (f l') l
where
f [] _ = return []
f ((er', y):ll) a@(er, x) = do
cmp <- rangeCmp er er'
let er'' = Intersection [er, er']
case cmp of
Comparable GT -> liftM ((er', (x, y)) :) $ f ll a
Incomparable Disjoint -> f ll a
Incomparable Overlap -> liftM ((er'', (x, y)) :) $ f ll a
-- this case combine LT and EQ
_ -> return [(er, (x, y))]
{- | The partition is restricted explicitly to the given range, that is,
each set of the partition is intersected with the set from the range
and the empty sets are filtered out.
-}
restrictPartition :: (CompareIO m, Pretty a) =>
EPRange -> Partition a -> m (Partition a)
restrictPartition er p
| isStarRange er = return p
| otherwise =
case p of
AllPartition x -> return $ Partition [(er, x)]
Partition p' -> liftM Partition $ f p'
where
f [] = return []
f ((er', x):l) = do
cmp <- rangeCmp er er'
let er'' = Intersection [er, er']
case cmp of
Comparable EQ -> return [(er', x)]
Comparable LT -> return [(er, x)]
Comparable GT -> liftM ((er', x) :) $ f l
Incomparable Disjoint -> f l
Incomparable Overlap -> liftM ((er'', x) :) $ f l