{- |

Module : $Header$

Description : Parser for CspCASL processes

Copyright : (c)

License : GPLv2 or higher, see LICENSE.txt

Maintainer : a.m.gimblett@swan.ac.uk

Stability : experimental

Portability : portable

Parser for CSP-CASL processes.

-}

module CspCASL.Parse_CspCASL_Process

( channel_name

, parens

, parenList

, cspStartKeys

, cspSortId

, parseCspId

, csp_casl_process

, event_set

, process_name

, var

, commType

, bracedList

, procDeclOrDefn

) where

import Text.ParserCombinators.Parsec

import CASL.AS_Basic_CASL

import qualified CASL.Formula as CASL

import Common.AnnoState

import Common.Id

import Common.Keywords

import Common.Lexer

import Common.Parsec

import Common.Token (parseId, sortId, varId)

import CspCASL.AS_CspCASL_Process

import CspCASL.CspCASL_Keywords

csp_casl_process :: AParser st PROCESS

csp_casl_process = cond_proc <|> par_proc

cond_proc :: AParser st PROCESS

cond_proc = do

ift <- asKey ifS

f <- formula

asKey thenS

p <- csp_casl_process

asKey elseS

q <- csp_casl_process

return $ ConditionalProcess f p q $ compRange ift q

par_proc :: AParser st PROCESS

par_proc = choice_proc >>= par_proc'

par_proc' :: PROCESS -> AParser st PROCESS

par_proc' lp = do

asKey interleavingS

rp <- choice_proc

par_proc' (Interleaving lp rp (compRange lp rp))

<|> do

asKey synchronousS

rp <- choice_proc

par_proc' (SynchronousParallel lp rp (compRange lp rp))

<|> do

asKey genpar_openS

es <- event_set <?> "communication type"

asKey genpar_closeS

rp <- choice_proc

par_proc' (GeneralisedParallel lp es rp (compRange lp rp))

<|> do

asKey alpar_openS

les <- event_set

asKey alpar_sepS

res <- event_set

asKey alpar_closeS

rp <- choice_proc

par_proc' (AlphabetisedParallel lp les res rp (compRange lp rp))

<|> return lp

choice_proc :: AParser st PROCESS

choice_proc = seq_proc >>= choice_proc'

choice_proc' :: PROCESS -> AParser st PROCESS

choice_proc' lp = do

asKey external_choiceS

rp <- seq_proc

choice_proc' (ExternalChoice lp rp (compRange lp rp))

<|> do

asKey internal_choiceS

rp <- seq_proc

choice_proc' (InternalChoice lp rp (compRange lp rp))

<|> return lp

seq_proc :: AParser st PROCESS

seq_proc = pref_proc >>= seq_proc'

cspStartKeys :: [String]

cspStartKeys = startCspKeywords ++ startKeyword

seqSym :: AParser st Token

seqSym = asKey sequentialS `notFollowedWith`

(forget procDeclOrDefn <|> choice (map (forget . asKey) cspStartKeys))

seq_proc' :: PROCESS -> AParser st PROCESS

seq_proc' lp = do

asKey doubleSemis <|> seqSym

rp <- pref_proc

seq_proc' (Sequential lp rp (compRange lp rp))

<|> return lp

pref_proc :: AParser st PROCESS

pref_proc = do

e <- event

p <- pref_proc

return (PrefixProcess e p (compRange e p))

<|> hid_ren_proc <|> cond_proc

hid_ren_proc :: AParser st PROCESS

hid_ren_proc = prim_proc >>= hid_ren_proc'

hid_ren_proc' :: PROCESS -> AParser st PROCESS

hid_ren_proc' lp = do

asKey hiding_procS

es <- event_set

hid_ren_proc' (Hiding lp es (compRange lp es))

<|> do

asKey ren_proc_openS

rn <- renaming

ck <- asKey ren_proc_closeS

hid_ren_proc' (RenamingProcess lp rn (compRange lp ck))

<|> return lp

-- | parser for parens

parens :: AParser st a -> AParser st a

parens p = oParenT >> p << cParenT

-- | parser for comma-separated items in parens

parenList :: AParser st a -> AParser st [a]

parenList = parens . commaSep1

prim_proc :: AParser st PROCESS

prim_proc = do

pn <- process_name

args <- procArgs

return $ NamedProcess pn args $ compRange pn args

<|> parens csp_casl_process

<|> do

rk <- asKey runS

es <- parens event_set

return $ Run es $ getRange rk

<|> do

ck <- asKey chaosS

es <- parens event_set

return $ Chaos es $ getRange ck

<|> fmap (Div . getRange) (asKey divS)

<|> fmap (Stop . getRange) (asKey stopS)

<|> fmap (Skip . getRange) (asKey skipS)

-- | Parse a process name which can be a simple one or a fully qualified one.

process_name :: AParser st FQ_PROCESS_NAME

process_name = qualProc <|> fmap PROCESS_NAME processId

-- | Parse a process identifier

processId :: AParser st PROCESS_NAME

processId = do

s <- var

(c, p) <- option ([], nullRange) cspComps

return (Id [s] c p)

cspComps :: AParser st ([Id], Range)

cspComps = try $ do

o <- pToken $ string "[" << notFollowedBy (oneOf "[]|")

(ts, ps) <- parseId cspKeywords `separatedBy` commaT

c <- cBracketT

return (ts, toRange o ps c)

channel_name :: AParser st CHANNEL_NAME

channel_name = cspSortId

-- List of arguments to a named process

procArgs :: AParser st [TERM ()]

procArgs = optionL $ parenList $ CASL.term cspKeywords

event_set :: AParser st EVENT_SET

event_set = do

cts <- alphabet

return (EventSet cts (getRange cts))

{- Events may be simple CASL terms or channel send/receives or

internal / external prefix choice. -}

event :: AParser st EVENT

event = ((prefixChoice <|> chanComm) << asKey prefix_procS)

<|> try (term_event << asKey prefix_procS)

chanComm :: AParser st EVENT

chanComm = do

(cn, sr) <- try $ pair channel_name

$ asKey chan_sendS <|> asKey chan_receiveS

if tokStr sr == chan_sendS then do

v <- try $ var << asKey svar_sortS

s <- cspSortId

return (ChanNonDetSend cn v s (compRange cn s))

<|> do

t <- CASL.term cspKeywords

return (ChanSend cn t (getRange cn))

else do

v <- var << asKey svar_sortS

s <- cspSortId

return (ChanRecv cn v s (compRange cn s))

prefixChoice :: AParser st EVENT

prefixChoice = do

constr <- fmap (const InternalPrefixChoice) (asKey internal_choiceS)

<|> fmap (const ExternalPrefixChoice) (asKey external_choiceS)

v <- var

asKey svar_sortS

s <- cspSortId

return $ constr v s $ getRange s

term_event :: AParser st EVENT

term_event = do

t <- CASL.term cspKeywords

return (TermEvent t (getRange t))

{- Formulas are CASL formulas. We make our own wrapper around them

however. -}

formula :: AParser st (FORMULA ())

formula = CASL.formula cspKeywords

{- Primitive renaming is done using an operator name or a predicate

name. They're both Ids. Separation between operator or predicate

(or some other non-applicable Id) must be a static analysis

problem. -}

renaming :: AParser st RENAMING

renaming = fmap Renaming $ parseCspId `sepBy1` commaT

-- names come from CASL/Hets.

var :: AParser st VAR

var = varId cspKeywords

parseCspId :: AParser st Id

parseCspId = parseId cspKeywords

cspSortId :: AParser st SORT

cspSortId = sortId cspKeywords

-- Composition of ranges

compRange :: (GetRange a, GetRange b) => a -> b -> Range

compRange x y = getRange x `appRange` getRange y

-- * parse the beginning of a process declaration or equation

-- | parse many vars with the same sort

sortedVars :: AParser st (Either [SORT] VAR_DECL)

sortedVars = do

is <- commaSep1 cspSortId

ms <- optionMaybe $ pair colonT cspSortId

case ms of

Nothing -> return $ Left is

Just (r, s) -> if all isSimpleId is

then return $ Right $ Var_decl (map idToSimpleId is) s $ tokPos r else

fail "expected only simple vars before colon"

-- | parse variables with possibly different sorts

manySortedVars :: AParser st (Either [SORT] [VAR_DECL])

manySortedVars = do

e <- sortedVars

case e of

Left s -> return $ Left s

Right vd -> do

vs <- optionL $ anSemiOrComma

>> fmap fst (CASL.varDecls cspKeywords)

return $ Right $ vd : vs

-- | parse a sort or a sorted channel

commType :: AParser st CommType

commType = do

s <- cspSortId

do

colonT

r <- cspSortId

return $ CommTypeChan $ TypedChanName s r

<|> return (CommTypeSort s)

-- | parse a possibly empty list of comm types within braces

bracedList :: AParser st [CommType]

bracedList = braces $ sepBy commType commaT

-- | parse a set of comm types possibly within braces or the empty set

alphabet :: AParser st [CommType]

alphabet = bracedList <|> sepBy1 commType commaT

procTail :: AParser st PROC_ALPHABET

procTail = fmap ProcAlphabet $ colonT >> alphabet

procDecl :: AParser st FQ_PROCESS_NAME

procDecl = do

pn <- processId

ss <- optionL $ parenList cspSortId

al <- procTail

return $ FQ_PROCESS_NAME pn ss al

qualProc :: AParser st FQ_PROCESS_NAME

qualProc = do

try (oParenT >> asKey processS)

pd <- procDecl

cParenT

return pd

procDeclOrDefn :: AParser st (Either (FQ_PROCESS_NAME, [VAR])

(PROCESS_NAME, Either [SORT] [VAR_DECL], PROC_ALPHABET))

procDeclOrDefn = do

fqn <- qualProc

as <- optionL $ parenList var

equalT

return $ Left (fqn, as)

<|> do

pn <- processId

ma <- optionMaybe $ parens manySortedVars

mal <- optionMaybe procTail

case mal of

Nothing -> do

equalT

case ma of

Just (Left ss) | all isSimpleId ss ->

return $ Left (PROCESS_NAME pn, map idToSimpleId ss)

Nothing -> return $ Left (PROCESS_NAME pn, [])

_ -> fail "unexpected argument list"

Just al -> case ma of

Nothing -> do

me <- optionMaybe equalT

case me of

Nothing -> return $ Right (pn, Left [], al)

Just _ -> return $ Right (pn, Right [], al)

Just as -> case as of

Left ss -> return $ Right (pn, Left ss, al)

Right vds -> do

equalT

return $ Right (pn, Right vds, al)