{- HetCATS/CASL/MixfixParser.hs

$Id$

Author: Christian Maeder

Year: 2002

Mixfix analysis of terms

Missing features:

- the positions of Ids from %string, %list, %number and %floating annotations

is not changed within applications (and might be misleading)

- using (Set State) instead of [State] avoids explosion

but detection of local ambiguities (that of subterms) is more difficult

solution: equal list states should be merged into a single state

that stores the local ambiguity

-}

module CASL.MixfixParser ( resolveFormula, resolveMixfix)

where

import CASL.AS_Basic_CASL

import Common.GlobalAnnotations

import Common.Result

import Common.Id

import Common.Lib.Map as Map hiding (filter, split, map)

import Common.Lib.Set as Set hiding (filter, split, single, insert)

import Common.Lexer

import Control.Monad

import Common.Lib.Parsec

import qualified Char as C

import Data.List(intersperse)

import Common.GlobalAnnotationsFunctions

import CASL.Formula(updFormulaPos)

import qualified CASL.ShowMixfix as ShowMixfix (showTerm)

showTerm :: GlobalAnnos -> TERM -> String

showTerm _ t = ShowMixfix.showTerm t ""

-- Earley Algorithm

data State = State Id

[Pos] -- positions of Id tokens

[TERM] -- currently collected arguments

-- both in reverse order

[Token] -- only tokens after the "dot" are given

Int -- index into the ParseMap/input string

instance Eq State where

State r1 _ _ t1 p1 == State r2 _ _ t2 p2 = (r1, t1, p1) == (r2, t2, p2)

instance Ord State where

State r1 _ _ t1 p1 <= State r2 _ _ t2 p2 = (r1, t1, p1) <= (r2, t2, p2)

termStr :: String

termStr = "(T)"

commaTok, parenTok, termTok :: Token

commaTok = mkSimpleId "," -- for list elements

termTok = mkSimpleId termStr

parenTok = mkSimpleId "(..)"

colonTok, asTok, varTok, opTok, predTok :: Token

colonTok = mkSimpleId ":"

asTok = mkSimpleId "as"

varTok = mkSimpleId "(v)"

opTok = mkSimpleId "(o)"

predTok = mkSimpleId "(p)"

mkState :: Int -> Id -> State

mkState i ide = State ide [] [] (getTokenList termStr ide) i

mkApplState :: Int -> Id -> State

mkApplState i ide = State ide [] []

(getTokenList place ide ++ [parenTok]) i

listId :: Id

-- unique id (usually "[]" yields two tokens)

listId = Id [mkSimpleId "[]"] [] []

listStates :: GlobalAnnos -> Int -> [State]

-- no empty list (can be written down directly)

listStates g i =

let listState toks = State listId [] [] toks i

(b1, b2) = listBrackets g

in if null b1 || null b2 then []

else [ listState (b1 ++ [termTok] ++ b2)

, listState (b1 ++ [termTok, commaTok] ++ b2)]

-- assume that b1 ++ b2 is included as Id for the empty list

-- these are the possible matches for the nonterminal TERM

-- the same states are used for the predictions

initialState :: GlobalAnnos -> Set Id -> Int -> [State]

initialState g ids i =

let mkTokState toks = State (Id toks [] []) [] [] toks i

is = Set.toList ids

in mkTokState [parenTok] :

mkTokState [termTok, colonTok] :

mkTokState [termTok, asTok] :

mkTokState [varTok] :

mkTokState [opTok] :

mkTokState [opTok, parenTok] :

mkTokState [predTok] :

mkTokState [predTok, parenTok] :

listStates g i ++

map (mkState i) is ++

map (mkApplState i) is

type ParseMap = Map Int [State]

lookUp :: (Ord a, MonadPlus m) => Map a (m b) -> a -> (m b)

lookUp ce k = findWithDefault mzero k ce

-- match (and shift) a token (or partially finished term)

scan :: TERM -> Int -> ParseMap -> ParseMap

scan trm i m =

let t = case trm of

Mixfix_token x -> x

Mixfix_sorted_term _ _ -> colonTok

Mixfix_cast _ _ -> asTok

Mixfix_parenthesized _ _ -> parenTok

Application (Qual_op_name _ _ _) [] _ -> opTok

Mixfix_qual_pred _ -> predTok

_ -> varTok

in

Map.insert (i+1) (

foldr (\ (State o b a ts k) l ->

if null ts || head ts /= t then l

else let p = tokPos t : b in

if t == commaTok && o == listId then

-- list elements separator

(State o p a

(termTok : commaTok : tail ts) k)

: (State o p a (termTok : tail ts) k) : l

else if t == parenTok then

(State o b (trm : a) (tail ts) k) : l

else if t == varTok || t == opTok || t == predTok then

(State o b [trm] (tail ts) k) : l

else if t == colonTok || t == asTok then

(State o b [mkTerm $ head a] [] k) : l

else (State o p a (tail ts) k) : l) []

(lookUp m i)) m

where mkTerm t1 = case trm of

Mixfix_sorted_term s ps -> Sorted_term t1 s ps

Mixfix_cast s ps -> Cast t1 s ps

_ -> t1

-- precedence graph stuff

checkArg :: GlobalAnnos -> AssocEither -> Id -> Id -> Bool

checkArg g dir op arg =

if arg == op

then isAssoc dir (assoc_annos g) op || not (isInfix op)

else

case precRel (prec_annos g) op arg of

Lower -> True

Higher -> False

ExplGroup BothDirections -> False

ExplGroup NoDirection -> not $ isInfix arg

checkAnyArg :: GlobalAnnos -> Id -> Id -> Bool

checkAnyArg g op arg =

case precRel (prec_annos g) op arg of

ExplGroup BothDirections -> isInfix op && op == arg

_ -> True

isLeftArg, isRightArg :: Id -> Int -> Bool

isLeftArg (Id ts _ _) n = n + 1 == (length $ takeWhile isPlace ts)

isRightArg (Id ts _ _) n = n == (length $ filter isPlace ts) -

(length $ takeWhile isPlace (reverse ts))

filterByPrec :: GlobalAnnos -> State -> State -> Bool

filterByPrec _ _ (State _ _ _ [] _) = False

filterByPrec g (State argIde _ _ _ _) (State opIde _ args (hd:_) _) =

if hd == termTok then

if opIde == listId || argIde == listId then True

else let n = length args in

if isLeftArg opIde n then

if isPostfix opIde && (isPrefix argIde

|| isInfix argIde) then False

else checkArg g ALeft opIde argIde

else if isRightArg opIde n then

if isPrefix opIde && isInfix argIde then False

else checkArg g ARight opIde argIde

else checkAnyArg g opIde argIde

else False

-- reconstructing positions

setPlainIdePos :: Id -> [Pos] -> (Id, [Pos])

setPlainIdePos (Id ts cs _) ps =

let (places, toks) = span isPlace (reverse ts)

pls = reverse places

f = zipWith (\ a b -> up_pos (const b) a)

(ps1, ps2) = splitAt (length toks) ps

front = f (reverse toks) ps1

in if null cs then

let (ps3, ps4) = splitAt (length pls) ps2

in (Id (front ++ f pls ps3) [] [], ps4)

else let (newCs, ps3, ps4) = foldl (\ (prevCs, seps, rest) a ->

let (c1, qs) = setPlainIdePos a rest

in (c1: prevCs, head qs : seps, tail qs))

([], [head ps2], tail ps2) cs

(ps6, ps7) = splitAt (length pls) ps4

in (Id (front ++ f pls ps6) (reverse newCs) (reverse ps3), ps7)

setIdePos :: Id -> [TERM] -> [Pos] -> Id

setIdePos i@(Id ts _ _) ar ps =

let nt = length $ getTokenList place i

np = length ps

na = length $ filter isPlace ts

(_, toks) = span isPlace (reverse ts)

in if nt == np then -- literal places

let (newId, []) = setPlainIdePos i ps

in newId

else if np + na == nt && na == length ar then -- mixfix

let (newTps, rargs, rqs) = mergePos (reverse toks) ar ps

(newId, []) = setPlainIdePos i

(newTps ++ rqs ++ map posOfTerm rargs)

in newId

else error "setIdePos"

where mergePos [] args qs = ([], args, qs)

mergePos (t:rs) args qs =

if isPlace t then

let (tokps, rargs, rqs) = mergePos rs (tail args) qs

in (posOfTerm (head args) : tokps, rargs, rqs)

else let (tokps, rargs, rqs) = mergePos rs args (tail qs)

in (head qs : tokps, rargs, rqs)

-- constructing the parse tree from (the final) parser state(s)

stateToAppl :: State -> TERM

stateToAppl (State ide rs a _ _) =

let vs = getTokenList place ide

ar = reverse a

qs = reverse rs

in if vs == [termTok, colonTok]

|| vs == [termTok, asTok]

|| vs == [varTok]

|| vs == [opTok]

|| vs == [predTok]

|| vs == [parenTok]

then head ar

else if vs == [opTok, parenTok]

then let Application q _ _ = head ar

Mixfix_parenthesized ts ps = head a

in Application q ts ps

else if vs == [predTok, parenTok]

then Mixfix_term [head ar, head a]

else case ar of

[Mixfix_parenthesized ts ps] ->

Application (Op_name

(setIdePos ide ts qs))

ts ps

_ -> let newIde@(Id (t:_) _ _) = setIdePos ide ar qs

pos = if isPlace t then posOfTerm $ head ar

else tokPos t

in Application (Op_name newIde) ar [pos]

-- true mixfix

asListAppl :: GlobalAnnos -> State -> TERM

asListAppl g s@(State i bs a _ _) =

if i == listId then

case list_lit $ literal_annos g of

Nothing -> error "asListAppl"

Just (b, c, f) ->

let (b1, b2) = getListBrackets b

nb1 = length b1

nb2 = length b2

ra = reverse a

na = length ra

nb = length bs

mkList [] ps = asAppl c [] (head ps)

mkList (hd:tl) ps = asAppl f [hd, mkList tl (tail ps)] (head ps)

in if null a then asAppl c [] (if null bs then nullPos else last bs)

else if nb + 1 == nb1 + nb2 + na then

let br = reverse bs

br1 = drop (nb1 - 1) br

in mkList (reverse a) br1

else error "asListAppl"

else stateToAppl s

-- final complete/reduction phase

-- when a grammar rule (mixfix Id) has been fully matched

collectArg :: GlobalAnnos -> ParseMap -> State -> [State]

-- pre: finished rule

collectArg g m s@(State _ _ _ _ k) =

map (\ (State o b a ts k1) ->

State o b (asListAppl g s : a)

(tail ts) k1)

$ filter (filterByPrec g s)

$ lookUp m k

compl :: GlobalAnnos -> ParseMap -> [State] -> [State]

compl g m l =

concat $ map (collectArg g m)

$ filter (\ (State _ _ _ ts _) -> null ts) l

complRec :: GlobalAnnos -> ParseMap -> [State] -> [State]

complRec g m l = let l1 = compl g m l in

if null l1 then l else complRec g m l1 ++ l

complete :: GlobalAnnos -> Int -> ParseMap -> ParseMap

complete g i m = Map.insert i (complRec g m $ lookUp m i) m

-- predict which rules/ids might match for (the) nonterminal(s) (termTok)

-- provided the "dot" is followed by a nonterminal

predict :: GlobalAnnos -> Set Id -> Int -> ParseMap -> ParseMap

predict g is i m = if i /= 0 && any (\ (State _ _ _ ts _) -> not (null ts)

&& head ts == termTok)

(lookUp m i)

then insertWith (++) i (initialState g is i) m

else m

type Chart = (Int, [Diagnosis], ParseMap)

nextState :: GlobalAnnos -> Set Id -> TERM -> Chart -> Chart

nextState g is trm (i, ds, m) =

let m1 = complete g (i+1) $

scan trm i $

predict g is i m

in if null (lookUp m1 (i+1)) && null ds

then (i+1, Diag Error ("unexpected mixfix token: "

++ showTerm g trm)

(posOfTerm trm) : ds, m)

else (i+1, ds, m1)

iterateStates :: GlobalAnnos -> Set Id -> Set Id -> [TERM] -> Chart -> Chart

iterateStates g ops preds terms c@(i, ds, m) =

let self = iterateStates g ops preds

resolveTerm = resolveMixfix g ops preds False

in if null terms then c

else case head terms of

Mixfix_term ts -> self (ts ++ tail terms) c

Mixfix_bracketed ts ps ->

self (expand "[" "]" ts ps ++ tail terms) c

Mixfix_braced ts ps ->

self (expand "{" "}" ts ps ++ tail terms) c

Mixfix_parenthesized ts ps ->

let Result mds v =

do tsNew <- mapM resolveTerm ts

return (Mixfix_parenthesized tsNew ps)

tNew = case v of Nothing -> head terms

Just x -> x

in self (tail terms) (nextState g ops tNew (i, ds++mds, m))

Conditional t1 f2 t3 ps ->

let Result mds v =

do t4 <- resolveTerm t1

f5 <- resolveFormula g ops preds f2

t6 <- resolveTerm t3

return (Conditional t4 f5 t6 ps)

tNew = case v of Nothing -> head terms

Just x -> x

in self (tail terms) (nextState g ops tNew (i, ds++mds, m))

Mixfix_token t -> let (ds1, trm) =

convertMixfixToken (literal_annos g) t

in self (tail terms)

(nextState g ops trm (i, ds1++ds, m))

t -> self (tail terms) (nextState g ops t c)

where expand = expandPos Mixfix_token

posOfTerm :: TERM -> Pos

posOfTerm trm =

case trm of

Mixfix_token t -> tokPos t

Mixfix_term ts -> posOfTerm (head ts)

Simple_id i -> tokPos i

Mixfix_qual_pred p ->

case p of

Pred_name i -> posOfId i

Qual_pred_name _ _ ps -> first (Just ps)

Application (Qual_op_name _ _ ps) [] [] -> first (Just ps)

_ -> first $ get_pos_l trm

where first ps = case ps of

Nothing -> nullPos

Just l -> if null l then nullPos else head l

getAppls :: GlobalAnnos -> Int -> ParseMap -> [TERM]

getAppls g i m =

map (asListAppl g) $

filter (\ (State _ _ _ ts k) -> null ts && k == 0) $

lookUp m i

resolveMixfix :: GlobalAnnos -> Set Id -> Set Id -> Bool -> TERM -> Result TERM

resolveMixfix g ops preds mayBeFormula trm =

let (i, ds, m) = iterateStates g ops preds [trm]

(0, [], Map.single 0 $ initialState g

(if mayBeFormula then ops `Set.union` preds else ops) 0)

ts = getAppls g i m

in if null ts then if null ds then

plain_error trm ("no resolution for term: "

++ showTerm g trm)

(posOfTerm trm)

else Result ds (Just trm)

else if null $ tail ts then Result ds (Just (head ts))

else Result (Diag Error ("ambiguous mixfix term\n\t" ++

(concat

$ intersperse "\n\t"

$ map (showTerm g)

$ take 5 ts)) (posOfTerm trm) : ds) (Just trm)

resolveFormula :: GlobalAnnos -> Set Id -> Set Id -> FORMULA -> Result FORMULA

resolveFormula g ops preds frm =

let self = resolveFormula g ops preds

resolveTerm = resolveMixfix g ops preds False in

case frm of

Quantification q vs fOld ps ->

let varIds = foldl (\ l (Var_decl va _ _) ->

map (\t->Id[t][][]) va ++ l) [] vs

in

do fNew <- resolveFormula g (Set.fromList varIds `Set.union` ops)

preds fOld

return $ Quantification q vs fNew ps

Conjunction fsOld ps ->

do fsNew <- mapM self fsOld

return $ Conjunction fsNew ps

Disjunction fsOld ps ->

do fsNew <- mapM self fsOld

return $ Disjunction fsNew ps

Implication f1 f2 ps ->

do f3 <- self f1

f4 <- self f2

return $ Implication f3 f4 ps

Equivalence f1 f2 ps ->

do f3 <- self f1

f4 <- self f2

return $ Equivalence f3 f4 ps

Negation fOld ps ->

do fNew <- self fOld

return $ Negation fNew ps

Predication sym tsOld ps ->

do tsNew <- mapM resolveTerm tsOld

return $ Predication sym tsNew ps

Definedness tOld ps ->

do tNew <- resolveTerm tOld

return $ Definedness tNew ps

Existl_equation t1 t2 ps ->

do t3 <- resolveTerm t1

t4 <- resolveTerm t2

return $ Existl_equation t3 t4 ps

Strong_equation t1 t2 ps ->

do t3 <- resolveTerm t1

t4 <- resolveTerm t2

return $ Strong_equation t3 t4 ps

Membership tOld s ps ->

do tNew <- resolveTerm tOld

return $ Membership tNew s ps

Mixfix_formula tOld ->

do tNew <- resolveMixfix g ops preds True tOld

mkPredication tNew

where mkPredication t =

case t of

Mixfix_parenthesized [t0] ps ->

do p <- mkPredication t0

return $ if null ps then p

else updFormulaPos (head ps) (last ps) p

Application (Op_name ide) args ps ->

let p = Predication (Pred_name ide) args ps in

if ide `Set.member` preds then return p

else plain_error p

("not a predicate: " ++ showId ide "")

(posOfTerm t)

Mixfix_qual_pred qide ->

return $ Predication qide [] []

Mixfix_term [Mixfix_qual_pred qide,

Mixfix_parenthesized ts ps] ->

return $ Predication qide ts ps

Mixfix_term _ -> return $ Mixfix_formula t -- still wrong

_ -> plain_error (Mixfix_formula t)

("not a formula: " ++ showTerm g t)

(posOfTerm t)

f -> return f

-- ---------------------------------------------------------------

-- convert literals

-- ---------------------------------------------------------------

makeStringTerm :: Id -> Id -> Token -> TERM

makeStringTerm c f tok =

makeStrTerm (incSourceColumn sp 1) str

where

sp = tokPos tok

str = init (tail (tokStr tok))

makeStrTerm p l =

if null l then asAppl c [] p

else let (hd, tl) = splitString caslChar l

in asAppl f [asAppl (Id [Token ("'" ++ hd ++ "'") p] [] []) [] p,

makeStrTerm (incSourceColumn p $ length hd) tl] p

makeNumberTerm :: Id -> Token -> TERM

makeNumberTerm f t@(Token n p) =

case n of

[] -> error "makeNumberTerm"

[_] -> asAppl (Id [t] [] []) [] p

hd:tl -> asAppl f [asAppl (Id [Token [hd] p] [] []) [] p,

makeNumberTerm f (Token tl

(incSourceColumn p 1))] p

makeFraction :: Id -> Id -> Token -> TERM

makeFraction f d t@(Token s p) =

let (n, r) = span (\c -> c /= '.') s

dotOffset = length n

in if null r then makeNumberTerm f t

else asAppl d [makeNumberTerm f (Token n p),

makeNumberTerm f (Token (tail r)

(incSourceColumn p $ dotOffset + 1))]

$ incSourceColumn p dotOffset

makeSignedNumber :: Id -> Token -> TERM

makeSignedNumber f t@(Token n p) =

case n of

[] -> error "makeSignedNumber"

hd:tl ->

if hd == '-' || hd == '+' then

asAppl (Id [Token [hd] p] [] [])

[makeNumberTerm f (Token tl $ incSourceColumn p 1)] p

else makeNumberTerm f t

makeFloatTerm :: Id -> Id -> Id -> Token -> TERM

makeFloatTerm f d e t@(Token s p) =

let (m, r) = span (\c -> c /= 'E') s

offset = length m

in if null r then makeFraction f d t

else asAppl e [makeFraction f d (Token m p),

makeSignedNumber f (Token (tail r)

$ incSourceColumn p (offset + 1))]

$ incSourceColumn p offset

asAppl :: Id -> [TERM] -> Pos -> TERM

asAppl f args p = let pos = if null args then [] else [p]

in Application (Op_name f) args pos

-- analyse Mixfix_token

convertMixfixToken:: LiteralAnnos -> Token -> ([Diagnosis], TERM)

convertMixfixToken ga t =

if isString t then

case string_lit ga of

Nothing -> err "string"

Just (c, f) -> ([], makeStringTerm c f t)

else if isNumber t then

case number_lit ga of

Nothing -> err "number"

Just f -> if isFloating t then

case float_lit ga of

Nothing -> err "floating"

Just (d, e) -> ([], makeFloatTerm f d e t)

else ([], makeNumberTerm f t)

else ([], te)

where te = Mixfix_token t

err s = ([Diag Error ("missing %" ++ s ++ " annotation") (tokPos t)]

, te)