module DDC.Core.Parser.Exp
( pExp
, pExpApp
, pExpAtom, pExpAtomSP
, pLetsSP
, pType
, pTypeApp
, pTypeAtom)
where
import DDC.Core.Exp
import DDC.Core.Parser.Witness
import DDC.Core.Parser.Param
import DDC.Core.Parser.Type
import DDC.Core.Parser.Context
import DDC.Core.Parser.Base
import DDC.Core.Lexer.Tokens
import DDC.Core.Compounds
import DDC.Base.Parser ((<?>), SourcePos)
import qualified DDC.Base.Parser as P
import qualified DDC.Type.Compounds as T
import Control.Monad.Error
pExp :: Ord n => Context -> Parser n (Exp SourcePos n)
pExp c
= P.choice
[ do sp <- pTokSP KBackSlash
bs <- liftM concat $ P.many1 (pBinds c)
pTok KDot
xBody <- pExp c
return $ foldr (XLam sp) xBody bs
, do sp <- pTokSP KBigLambda
bs <- liftM concat $ P.many1 (pBinds c)
pTok KDot
xBody <- pExp c
return $ foldr (XLAM sp) xBody bs
, do (lts, sp) <- pLetsSP c
pTok KIn
x2 <- pExp c
return $ XLet sp lts x2
, do pTok KDo
pTok KBraceBra
xx <- pStmts c
pTok KBraceKet
return $ xx
, do sp <- pTokSP KWithRegion
u <- P.choice
[ do n <- pVar
return $ UName n
, do n <- pCon
return $ UPrim n kRegion]
pTok KIn
x <- pExp c
return $ XLet sp (LWithRegion u) x
, do sp <- pTokSP KCase
x <- pExp c
pTok KOf
pTok KBraceBra
alts <- P.sepEndBy1 (pAlt c) (pTok KSemiColon)
pTok KBraceKet
return $ XCase sp x alts
, do
sp <- pTokSP KLetCase
p <- pPat c
pTok (KOp "=")
x1 <- pExp c
pTok KIn
x2 <- pExp c
return $ XCase sp x1 [AAlt p x2]
, do sp <- pTokSP KMatch
p <- pPat c
pTok KArrowDashLeft
x1 <- pExp c
pTok KElse
x2 <- pExp c
pTok KIn
x3 <- pExp c
return $ XCase sp x1 [AAlt p x3, AAlt PDefault x2]
, do sp <- pTokSP KWeakEff
pTok KSquareBra
t <- pType c
pTok KSquareKet
pTok KIn
x <- pExp c
return $ XCast sp (CastWeakenEffect t) x
, do sp <- pTokSP KWeakClo
pTok KBraceBra
xs <- liftM (map fst . concat)
$ P.sepEndBy1 (pArgSPs c) (pTok KSemiColon)
pTok KBraceKet
pTok KIn
x <- pExp c
return $ XCast sp (CastWeakenClosure xs) x
, do sp <- pTokSP KPurify
w <- pWitness c
pTok KIn
x <- pExp c
return $ XCast sp (CastPurify w) x
, do sp <- pTokSP KForget
w <- pWitness c
pTok KIn
x <- pExp c
return $ XCast sp (CastForget w) x
, do sp <- pTokSP KBox
x <- pExp c
return $ XCast sp CastBox x
, do sp <- pTokSP KRun
x <- pExp c
return $ XCast sp CastRun x
, do pExpApp c
]
<?> "an expression"
pExpApp :: Ord n => Context -> Parser n (Exp SourcePos n)
pExpApp c
= do (x1, _) <- pExpAtomSP c
P.choice
[ do xs <- liftM concat $ P.many1 (pArgSPs c)
return $ foldl (\x (x', sp) -> XApp sp x x') x1 xs
, return x1]
<?> "an expression or application"
pArgSPs :: Ord n => Context -> Parser n [(Exp SourcePos n, SourcePos)]
pArgSPs c
= P.choice
[ do sp <- pTokSP KSquareBra
t <- pType c
pTok KSquareKet
return [(XType sp t, sp)]
, do sp <- pTokSP KSquareColonBra
ts <- P.many1 (pTypeAtom c)
pTok KSquareColonKet
return [(XType sp t, sp) | t <- ts]
, do sp <- pTokSP KBraceBra
w <- pWitness c
pTok KBraceKet
return [(XWitness sp w, sp)]
, do sp <- pTokSP KBraceColonBra
ws <- P.many1 (pWitnessAtom c)
pTok KBraceColonKet
return [(XWitness sp w, sp) | w <- ws]
, do (x, sp) <- pExpAtomSP c
return [(x, sp)]
]
<?> "a type, witness or expression argument"
pExpAtom :: Ord n => Context -> Parser n (Exp SourcePos n)
pExpAtom c
= do (x, _) <- pExpAtomSP c
return x
pExpAtomSP
:: Ord n
=> Context
-> Parser n (Exp SourcePos n, SourcePos)
pExpAtomSP c
= P.choice
[ do sp <- pTokSP KRoundBra
t <- pExp c
pTok KRoundKet
return (t, sp)
, do sp <- pTokSP KDaConUnit
return (XCon sp dcUnit, sp)
, do (con, sp) <- pConSP
return (XCon sp (DaConBound con), sp)
, do (lit, sp) <- pLitSP
return (XCon sp (DaConPrim lit (T.tBot T.kData)), sp)
, do (i, sp) <- pIndexSP
return (XVar sp (UIx i), sp)
, do (var, sp) <- pVarSP
return (XVar sp (UName var), sp)
]
<?> "a variable, constructor, or parenthesised type"
pAlt :: Ord n => Context -> Parser n (Alt SourcePos n)
pAlt c
= do p <- pPat c
pTok KArrowDash
x <- pExp c
return $ AAlt p x
pPat :: Ord n
=> Context -> Parser n (Pat n)
pPat c
= P.choice
[
do pTok KUnderscore
return $ PDefault
, do
nLit <- pLit
return $ PData (DaConPrim nLit (T.tBot T.kData)) []
, do pTok KDaConUnit
return $ PData dcUnit []
, do nCon <- pCon
bs <- liftM concat $ P.many (pBinds c)
return $ PData (DaConBound nCon) bs]
pBinds
:: Ord n
=> Context -> Parser n [Bind n]
pBinds c
= P.choice
[ do bs <- P.many1 pBinder
return [T.makeBindFromBinder b (T.tBot T.kData) | b <- bs]
, do pTok KRoundBra
bs <- P.many1 pBinder
pTok (KOp ":")
t <- pType c
pTok KRoundKet
return [T.makeBindFromBinder b t | b <- bs]
]
pLetsSP :: Ord n
=> Context -> Parser n (Lets SourcePos n, SourcePos)
pLetsSP c
= P.choice
[
do sp <- pTokSP KLet
(b1, x1) <- pLetBinding c
return (LLet b1 x1, sp)
, do sp <- pTokSP KLetRec
P.choice
[ do pTok KBraceBra
lets <- P.sepEndBy1 (pLetBinding c) (pTok KSemiColon)
pTok KBraceKet
return (LRec lets, sp)
, do ll <- pLetBinding c
return (LRec [ll], sp)
]
, do sp <- pTokSP KPrivate
brs <- P.manyTill pBinder
$ P.try $ P.lookAhead $ P.choice [pTok KIn, pTok KWith]
let bs = map (flip T.makeBindFromBinder T.kRegion) brs
r <- pLetWits c bs Nothing
return (r, sp)
, do sp <- pTokSP KExtend
t <- pType c
pTok KUsing
brs <- P.manyTill pBinder
$ P.try $ P.lookAhead
$ P.choice [pTok KUsing, pTok KWith, pTok KIn]
let bs = map (flip T.makeBindFromBinder T.kRegion) brs
r <- pLetWits c bs (Just t)
return (r, sp)
]
pLetWits :: Ord n
=> Context
-> [Bind n] -> Maybe (Type n)
-> Parser n (Lets SourcePos n)
pLetWits c bs mParent
= P.choice
[ do pTok KWith
pTok KBraceBra
wits <- P.sepBy (P.choice
[
do b <- pBinder
pTok (KOp ":")
t <- pTypeApp c
return $ T.makeBindFromBinder b t
, do t <- pTypeApp c
return $ BNone t ])
(pTok KSemiColon)
pTok KBraceKet
return (LPrivate bs mParent wits)
, do return (LPrivate bs mParent [])
]
pLetBinding
:: Ord n
=> Context
-> Parser n ( Bind n
, Exp SourcePos n)
pLetBinding c
= do b <- pBinder
P.choice
[ do
pTok (KOp ":")
t <- pType c
pTok (KOp "=")
xBody <- pExp c
return $ (T.makeBindFromBinder b t, xBody)
, do
pTok (KOp "=")
xBody <- pExp c
let t = T.tBot T.kData
return $ (T.makeBindFromBinder b t, xBody)
, do
ps <- liftM concat
$ P.many (pBindParamSpec c)
P.choice
[ do
pTok (KOp ":")
tBody <- pType c
sp <- pTokSP (KOp "=")
xBody <- pExp c
let x = expOfParams sp ps xBody
let t = funTypeOfParams c ps tBody
return (T.makeBindFromBinder b t, x)
, do sp <- pTokSP (KOp "=")
xBody <- pExp c
let x = expOfParams sp ps xBody
let t = T.tBot T.kData
return (T.makeBindFromBinder b t, x) ]
]
data Stmt n
= StmtBind SourcePos (Bind n) (Exp SourcePos n)
| StmtMatch SourcePos (Pat n) (Exp SourcePos n) (Exp SourcePos n)
| StmtNone SourcePos (Exp SourcePos n)
pStmt :: Ord n => Context -> Parser n (Stmt n)
pStmt c
= P.choice
[
P.try $
do br <- pBinder
sp <- pTokSP (KOp "=")
x1 <- pExp c
let t = T.tBot T.kData
let b = T.makeBindFromBinder br t
return $ StmtBind sp b x1
, P.try $
do p <- pPat c
sp <- pTokSP KArrowDashLeft
x1 <- pExp c
pTok KElse
x2 <- pExp c
return $ StmtMatch sp p x1 x2
, do x <- pExp c
return $ StmtNone (annotOfExp x) x
]
pStmts :: Ord n => Context -> Parser n (Exp SourcePos n)
pStmts c
= do stmts <- P.sepEndBy1 (pStmt c) (pTok KSemiColon)
case makeStmts stmts of
Nothing -> P.unexpected "do-block must end with a statement"
Just x -> return x
makeStmts :: [Stmt n] -> Maybe (Exp SourcePos n)
makeStmts ss
= case ss of
[StmtNone _ x]
-> Just x
StmtNone sp x1 : rest
| Just x2 <- makeStmts rest
-> Just $ XLet sp (LLet (BNone (T.tBot T.kData)) x1) x2
StmtBind sp b x1 : rest
| Just x2 <- makeStmts rest
-> Just $ XLet sp (LLet b x1) x2
StmtMatch sp p x1 x2 : rest
| Just x3 <- makeStmts rest
-> Just $ XCase sp x1
[ AAlt p x3
, AAlt PDefault x2]
_ -> Nothing