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ParseUtils.hs
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{-# OPTIONS_HADDOCK hide #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE PatternGuards #-}
-----------------------------------------------------------------------------
-- |
-- Module : Language.Haskell.Exts.ParseUtils
-- Copyright : (c) Niklas Broberg 2004-2009,
-- (c) The GHC Team, 1997-2000
-- License : BSD-style (see the file LICENSE.txt)
--
-- Maintainer : Niklas Broberg, [email protected]
-- Stability : stable
-- Portability : portable
--
-- Utilities for the Haskell-exts parser.
--
-----------------------------------------------------------------------------
module Language.Haskell.Exts.ParseUtils (
splitTyConApp -- PType -> P (Name,[Type])
, checkEnabled -- (Show e, Enabled e) => e -> P ()
, checkEnabledOneOf
, checkToplevel -- ??
, checkPatternGuards -- [Stmt] -> P ()
, mkRecConstrOrUpdate -- PExp -> [PFieldUpdate] -> P Exp
, checkPrec -- Integer -> P Int
, checkPContext -- PType -> P PContext
, checkContext -- PContext -> P Context
, checkAssertion -- PType -> P PAsst
, checkDataHeader -- PType -> P (Context,Name,[TyVarBind])
, checkClassHeader -- PType -> P (Context,Name,[TyVarBind])
, checkInstHeader -- PType -> P (Context,QName,[Type])
, checkDeriving -- [PType] -> P [Deriving]
, checkPattern -- PExp -> P Pat
, checkExpr -- PExp -> P Exp
, checkType -- PType -> P Type
, checkTyVar -- Name -> P PType
, bangType -- L -> BangType -> Type -> Type
, checkKind -- Kind -> P ()
, checkValDef -- SrcLoc -> PExp -> Maybe Type -> Rhs -> Binds -> P Decl
, checkExplicitPatSyn --
, checkClassBody -- [ClassDecl] -> P [ClassDecl]
, checkInstBody -- [InstDecl] -> P [InstDecl]
, checkUnQual -- QName -> P Name
, checkQualOrUnQual -- QName -> P QName
, checkSingleDecl -- [Decl] -> P Decl
, checkRevDecls -- [Decl] -> P [Decl]
, checkRevClsDecls -- [ClassDecl] -> P [ClassDecl]
, checkRevInstDecls -- [InstDecl] -> P [InstDecl]
, checkDataOrNew -- DataOrNew -> [QualConDecl] -> P ()
, checkDataOrNewG -- DataOrNew -> [GadtDecl] -> P ()
, checkSimpleType -- PType -> P (Name, [TyVarBind])
, checkSigVar -- PExp -> P Name
, checkDefSigDef -- Decl -> P Decl
, getGConName -- S.Exp -> P QName
, mkTyForall -- Maybe [TyVarBind] -> PContext -> PType -> PType
, mkRoleAnnotDecl --
, mkAssocType
, mkEThingWith
, splitTilde
-- HaRP
, checkRPattern -- PExp -> P RPat
-- Hsx
, checkEqNames -- XName -> XName -> P XName
, checkPageModule
, checkHybridModule
, mkDVar -- [String] -> String
-- Pragmas
, checkRuleExpr -- PExp -> P Exp
, readTool -- Maybe String -> Maybe Tool
-- Helpers
, updateQNameLoc -- l -> QName l -> QName l
, SumOrTuple(..), mkSumOrTuple
-- Parsed expressions and types
, PExp(..), PFieldUpdate(..), ParseXAttr(..), PType(..), PContext, PAsst(..)
, p_unit_con -- PExp
, p_tuple_con -- Boxed -> Int -> PExp
, p_unboxed_singleton_con -- PExp
, pexprToQName
) where
import Language.Haskell.Exts.Syntax hiding ( Type(..), Asst(..), Exp(..), FieldUpdate(..), XAttr(..), Context(..) )
import qualified Language.Haskell.Exts.Syntax as S ( Type(..), Asst(..), Exp(..), FieldUpdate(..), XAttr(..), Context(..), Role(..), PatternSynDirection(..))
import Language.Haskell.Exts.ParseSyntax
import Language.Haskell.Exts.ParseMonad
import Language.Haskell.Exts.Pretty
import Language.Haskell.Exts.SrcLoc hiding (loc)
import Language.Haskell.Exts.Extension
import Language.Haskell.Exts.ExtScheme
import Prelude hiding (mod)
import Data.List (intercalate, intersperse)
import Data.Maybe (fromJust, fromMaybe)
import Data.Either
import Control.Monad (when,unless)
#if __GLASGOW_HASKELL__ < 710
import Control.Applicative ((<$>))
#endif
type L = SrcSpanInfo
type S = SrcSpan
pexprToQName :: PExp l -> P (QName l)
pexprToQName (Con _ qn) = return qn
pexprToQName (List l []) = return $ Special l (ListCon l)
pexprToQName _ = fail "pexprToQName"
splitTyConApp :: PType L -> P (Name L, [S.Type L])
splitTyConApp t0 = do
(n, pts) <- split t0 []
ts <- mapM checkType pts
return (n,ts)
where
split :: PType L -> [PType L] -> P (Name L, [PType L])
split (TyApp _ t u) ts = split t (u:ts)
split (TyCon _ (UnQual _ t)) ts = return (t,ts)
split (TyInfix l a op b) ts = split (TyCon l (getMaybePromotedQName op)) (a:b:ts)
split _ _ = fail "Illegal data/newtype declaration"
-----------------------------------------------------------------------------
-- Checking for extensions
checkEnabled :: (Show e, Enabled e) => e -> P ()
checkEnabled e = do
exts <- getExtensions
unless (isEnabled e exts) $ fail errorMsg
where errorMsg = unwords
[ show e
, "language extension is not enabled."
, "Please add {-# LANGUAGE " ++ show e ++ " #-}"
, "pragma at the top of your module."
]
checkEnabledOneOf :: (Show e, Enabled e) => [e] -> P ()
checkEnabledOneOf es = do
exts <- getExtensions
unless (any (`isEnabled` exts) es) $
fail errorMsg
where errorMsg = unwords
[ "At least one of"
, joinOr id
, "language extensions needs to be enabled."
, "Please add:"
, joinOr (\s -> "{-# LANGUAGE " ++ s ++ " #-}")
, "language pragma at the top of your module."
]
joinOr f = concat . intersperse " or " . map (f . show) $ es
checkPatternGuards :: [Stmt L] -> P ()
checkPatternGuards [Qualifier _ _] = return ()
checkPatternGuards _ = checkEnabled PatternGuards
checkToplevel :: PExp t -> P ()
checkToplevel e = do
exts <- getExtensions
let isQQ = case e of
QuasiQuote {} -> isEnabled QuasiQuotes exts
_ -> False
unless isQQ (checkEnabled TemplateHaskell)
-----------------------------------------------------------------------------
-- Checking contexts
-- Check that a context is syntactically correct. Takes care of
-- checking for MPTCs, TypeOperators, TypeFamilies (for eq constraints)
-- and ImplicitParameters, but leaves checking of the class assertion
-- parameters for later.
checkPContext :: PType L -> P (PContext L)
checkPContext (TyTuple l Boxed ts) =
mapM checkAssertion ts >>= return . CxTuple l
checkPContext (TyCon l (Special _ (UnitCon _))) =
return $ CxEmpty l
checkPContext (TyParen l t) = do
c <- checkAssertion t
return $ CxSingle l (ParenA l c)
checkPContext t@(TyEquals tp _ _) = do
checkEnabledOneOf [TypeFamilies, GADTs]
return $ CxSingle tp $ TypeA tp t
checkPContext t = do
c <- checkAssertion t
return $ CxSingle (ann c) c
------------------------------------------------------------------------------------------------------------------- WORKING HERE
-- Check a single assertion according to the above, still leaving
-- the class assertion parameters for later.
checkAssertion :: PType L -> P (PAsst L)
-- We cannot even get here unless ImplicitParameters is enabled.
checkAssertion (TyParen l asst) = do
asst' <- checkAssertion asst
return $ ParenA l asst'
checkAssertion (TyPred _ p) = checkAAssertion p
-- We cannot even get here unless TypeFamilies or GADTs is enabled.
-- N.B.: this is called only when the equality assertion is part of a
-- tuple
checkAssertion t' = do
t'' <- checkAssertion' id [] t'
return $ TypeA (ann t'') t''
where -- class assertions must have at least one argument
checkAssertion' _ _ t@(TyEquals _ _ _) = return t
checkAssertion' fl ts (TyCon l c) = do
when (length ts < 1) $ checkEnabled FlexibleContexts
checkAndWarnTypeOperators c
return $ tyApps (fl l) (TyCon (fl l) c) ts
checkAssertion' fl ts (TyApp l a t) =
-- no check on t at this stage
checkAssertion' (const (fl l)) (t:ts) a
checkAssertion' fl _ (TyInfix l a op b) = do
-- infix operators require TypeOperators
checkAndWarnTypeOperators (getMaybePromotedQName op)
return $ TyInfix (fl l) a op b
checkAssertion' fl ts (TyParen l t) =
checkAssertion' (const (fl l)) ts t
checkAssertion' fl ts (TyVar l t) = do -- Dict :: cxt => Dict cxt
checkEnabled ConstraintKinds
return $ tyApps (fl l) (TyVar (fl l) t) ts
checkAssertion' _ _ t@(TyWildCard _ _) = return t
checkAssertion' _ _ t = do
checkEnabled QuantifiedConstraints -- anything goes
return t
tyApps :: L -> PType L -> [PType L] -> PType L
tyApps _ c [] = c
tyApps l c (a:aa) = tyApps l (TyApp l c a) aa
checkAAssertion :: PAsst L -> P (PAsst L)
checkAAssertion (TypeA _ t) = checkAssertion t
checkAAssertion (ParenA l a) = do
a' <- checkAAssertion a
return $ ParenA l a'
checkAAssertion p = return p
-- Check class/instance declaration for multiparams
checkMultiParam :: PType L -> P ()
checkMultiParam = checkMultiParam' []
where
checkMultiParam' ts (TyCon _ _) =
when (length ts /= 1) $ checkEnabled MultiParamTypeClasses
checkMultiParam' ts (TyApp _ a t) = checkMultiParam' (t:ts) a
checkMultiParam' _ (TyInfix _ _ _ _) = checkEnabled MultiParamTypeClasses
checkMultiParam' ts (TyParen _ t) = checkMultiParam' ts t
checkMultiParam' _ _ = return ()
getSymbol :: QName L -> Maybe String
getSymbol (UnQual _ (Symbol _ s)) = Just s
getSymbol (Qual _ _ (Symbol _ s)) = Just s
getSymbol _ = Nothing
-- | Checks whether the parameter is a symbol, and gives a nice warning for
-- "." if ExplicitForAll/TypeOperators are not enabled.
checkAndWarnTypeOperators :: QName L -> P ()
checkAndWarnTypeOperators c =
case getSymbol c of
Just s | s == "." -> checkEnabledOneOf [ExplicitForAll, TypeOperators]
| otherwise -> checkEnabled TypeOperators
Nothing -> return ()
-- Checks simple contexts for class and instance
-- headers. If FlexibleContexts is enabled then
-- anything goes, otherwise only tyvars are allowed.
checkSContext :: Maybe (PContext L) -> P (Maybe (S.Context L))
checkSContext (Just ctxt) = case ctxt of
CxEmpty l -> return $ Just $ S.CxEmpty l
CxSingle l a -> checkAsst a >>= return . Just . S.CxSingle l
CxTuple l as -> mapM checkAsst as >>= return . Just . S.CxTuple l
checkSContext _ = return Nothing
-- Checks ordinary contexts for sigtypes and data type
-- declarations. If FlexibleContexts is enabled then
-- anything goes, otherwise only tyvars OR tyvars
-- applied to types are allowed.
checkContext :: Maybe (PContext L) -> P (Maybe (S.Context L))
checkContext (Just ctxt) = case ctxt of
CxEmpty l -> return $ Just $ S.CxEmpty l
CxSingle l a -> checkAsst a >>= return . Just . S.CxSingle l
CxTuple l as -> mapM checkAsst as >>= return . Just . S.CxTuple l
checkContext _ = return Nothing
checkAsst :: PAsst L -> P (S.Asst L)
checkAsst asst =
case asst of
TypeA l pt -> do
t <- checkType pt
return $ S.TypeA l t
IParam l ipn pt -> do
t <- checkType pt
return $ S.IParam l ipn t
ParenA l a -> do
a' <- checkAsst a
return $ S.ParenA l a'
-----------------------------------------------------------------------------
-- Checking Headers
checkDataHeader :: PType L -> P (Maybe (S.Context L), DeclHead L)
checkDataHeader (TyForall _ Nothing _ cs t) = do
dh <- checkSimple "data/newtype" t
cs' <- checkContext cs
return (cs',dh)
checkDataHeader t = do
dh <- checkSimple "data/newtype" t
return (Nothing,dh)
checkClassHeader :: PType L -> P (Maybe (S.Context L), DeclHead L)
checkClassHeader (TyForall _ Nothing _ cs t) = do
checkMultiParam t
dh <- checkSimple "class" t
cs' <- checkSContext cs
return (cs',dh)
checkClassHeader t = do
checkMultiParam t
dh <- checkSimple "class" t
return (Nothing,dh)
checkSimple :: String -> PType L -> P (DeclHead L)
--checkSimple kw (TyApp _ l t) xs | isTyVarBind t = checkSimple kw l (toTyVarBind t : xs)
checkSimple kw (TyApp l h t) = do
tvb <- mkTyVarBind kw t
h' <- checkSimple kw h
return $ DHApp l h' tvb
checkSimple kw (TyInfix l t1 mq t2)
| c@(UnQual _ t) <- getMaybePromotedQName mq
= do
checkAndWarnTypeOperators c
tv1 <- mkTyVarBind kw t1
tv2 <- mkTyVarBind kw t2
return $ DHApp l (DHInfix l tv1 t) tv2
checkSimple _kw (TyCon _ c@(UnQual l t)) = do
checkAndWarnTypeOperators c
return (DHead l t)
checkSimple kw (TyParen l t) = do
dh <- checkSimple kw t
return (DHParen l dh)
checkSimple kw _ = fail ("Illegal " ++ kw ++ " declaration")
mkTyVarBind :: String -> PType L -> P (TyVarBind L)
mkTyVarBind _ (TyVar l n) = return $ UnkindedVar l n
mkTyVarBind _ (TyKind l (TyVar _ n) k) = return $ KindedVar l n k
mkTyVarBind _ (TyCon l c@(UnQual _ n@(Symbol _ _))) = checkAndWarnTypeOperators c >> return (UnkindedVar l n)
mkTyVarBind _ (TyKind l (TyCon _ c@(UnQual _ n@(Symbol _ _))) k) = checkAndWarnTypeOperators c >> return (KindedVar l n k)
mkTyVarBind kw _ = fail ("Illegal " ++ kw ++ " declaration")
{-
isTyVarBind :: PType L -> Bool
isTyVarBind (TyVar _ _) = True
--isTyVarBind (TyCon _ (UnQual _ n@(Symbol _ _))) = True
isTyVarBind (TyKind _ (TyVar _ _) _) = True
isTyVarBind _ = False
toTyVarBind :: PType L -> TyVarBind L
toTyVarBind (TyVar l n) = UnkindedVar l n
toTyVarBind (TyKind l (TyVar _ n) k) = KindedVar l n k
-}
checkInstHeader :: PType L -> P (InstRule L)
checkInstHeader (TyParen l t) = checkInstHeader t >>= return . IParen l
checkInstHeader (TyForall l mtvs _ cs t) = do
cs' <- checkSContext cs
checkMultiParam t
checkInsts (Just l) mtvs cs' t
checkInstHeader t = checkMultiParam t >> checkInsts Nothing Nothing Nothing t
checkInsts :: Maybe L -> Maybe [TyVarBind L] -> Maybe (S.Context L) -> PType L -> P (InstRule L)
checkInsts _ mtvs mctxt (TyParen l t) = checkInsts Nothing mtvs mctxt t >>= return . IParen l
checkInsts l1 mtvs mctxt t = do
t' <- checkInstsGuts t
return $ IRule (fromMaybe (fmap ann mctxt <?+> ann t') l1) mtvs mctxt t'
checkInstsGuts :: PType L -> P (InstHead L)
checkInstsGuts (TyApp l h t) = do
t' <- checkType t
h' <- checkInstsGuts h
return $ IHApp l h' t'
checkInstsGuts (TyCon l c) = do
checkAndWarnTypeOperators c
return $ IHCon l c
checkInstsGuts (TyInfix l a op b) = do
checkAndWarnTypeOperators (getMaybePromotedQName op)
[ta,tb] <- checkTypes [a,b]
return $ IHApp l (IHInfix l ta (getMaybePromotedQName op)) tb
checkInstsGuts (TyParen l t) = checkInstsGuts t >>= return . IHParen l
checkInstsGuts _ = fail "Illegal instance declaration"
checkDeriving :: [PType L] -> P [InstRule L]
checkDeriving = mapM (checkInsts Nothing Nothing Nothing)
-----------------------------------------------------------------------------
-- Checking Patterns.
-- We parse patterns as expressions and check for valid patterns below,
-- converting the expression into a pattern at the same time.
checkPattern :: PExp L -> P (Pat L)
checkPattern e = checkPat e []
checkPat :: PExp L -> [Pat L] -> P (Pat L)
checkPat (Con l c) args = do
let l' = foldl combSpanInfo l (map ann args)
return (PApp l' c args)
checkPat (App _ f x) args = do
x' <- checkPat x []
checkPat f (x':args)
checkPat (InfixApp _ l op r) args
| op =~= QVarOp () (UnQual () (Symbol () "!")) = do
-- We must have BangPatterns on
checkEnabled BangPatterns
let (e,es) = splitBang r []
ps <- mapM checkPattern (BangPat (ann op) e:es)
checkPat l (ps++args)
checkPat e' [] = case e' of
Var _ (UnQual l x) -> return (PVar l x)
Var _ (Special l (ExprHole _)) -> return (PWildCard l)
Lit l lit -> return (PLit l (Signless l2) lit)
where l2 = noInfoSpan . srcInfoSpan $ l
InfixApp loc l op r ->
case op of
QConOp _ c -> do
l' <- checkPat l []
r' <- checkPat r []
return (PInfixApp loc l' c r')
QVarOp ppos (UnQual _ (Symbol _ "+")) -> do
checkEnabled NPlusKPatterns
case (l,r) of
(Var _ (UnQual _ n@(Ident _ _)), Lit _ (Int kpos k _)) -> do
let pp = srcInfoSpan ppos
kp = srcInfoSpan kpos
return (PNPlusK (loc <** [pp,kp]) n k)
_ -> patFail ""
_ -> patFail ""
TupleSection l bx mes ->
if Nothing `notElem` mes
then do ps <- mapM (\e -> checkPat e []) (map fromJust mes)
return (PTuple l bx ps)
else fail "Illegal tuple section in pattern"
UnboxedSum l b a e ->
PUnboxedSum l b a <$> checkPattern e
List l es -> do
ps <- mapM checkRPattern es
if all isStdPat ps
then return . PList l $ map stripRP ps
-- we don't allow truly regular patterns unless the extension is enabled
else checkEnabled RegularPatterns >> return (PRPat l $ map fixRPOpPrec ps)
where isStdPat :: RPat L -> Bool
isStdPat (RPPat _ _) = True
isStdPat (RPAs _ _ p) = isStdPat p
isStdPat (RPParen _ p) = isStdPat p
isStdPat _ = False
stripRP :: RPat L -> Pat L
stripRP (RPPat _ p) = p
stripRP (RPAs l' n p) = PAsPat l' n (stripRP p)
stripRP (RPParen l' p) = PParen l' (stripRP p)
stripRP _ = error "cannot strip RP wrapper if not all patterns are base"
Paren l e -> do
p <- checkPat e []
return (PParen l p)
AsPat l n e -> do
p <- checkPat e []
return (PAsPat l n p)
WildCard l -> return (PWildCard l)
IrrPat l e -> do
p <- checkPat e []
return (PIrrPat l p)
ViewPat l e p -> do
e1 <- checkExpr e
return (PViewPat l e1 p)
RecConstr l c fs -> do
fs' <- mapM checkPatField fs
return (PRec l c fs')
NegApp l (Lit _ lit) ->
let siSign = last . srcInfoPoints $ l
lSign = infoSpan siSign [siSign]
in do
when (not . isNegatableLiteral $ lit) (patFail $ prettyPrint e')
return (PLit l (Negative lSign) lit)
ExpTypeSig l e t -> do
-- patterns cannot have signatures unless ScopedTypeVariables is enabled.
checkEnabled ScopedTypeVariables
p <- checkPat e []
return (PatTypeSig l p t)
-- Hsx
XTag l n attrs mattr cs -> do
pattrs <- mapM checkPAttr attrs
pcs <- mapM (\c -> checkPat c []) cs
mpattr <- maybe (return Nothing)
(\e -> do p <- checkPat e []
return $ Just p)
mattr
let cps = mkChildrenPat pcs
return $ PXTag l n pattrs mpattr cps
XETag l n attrs mattr -> do
pattrs <- mapM checkPAttr attrs
mpattr <- maybe (return Nothing)
(\e -> do p <- checkPat e []
return $ Just p)
mattr
return $ PXETag l n pattrs mpattr
XPcdata l pcdata -> return $ PXPcdata l pcdata
XExpTag l e -> do
p <- checkPat e []
return $ PXPatTag l p
XRPats l es -> do
rps <- mapM checkRPattern es
return (PXRPats l $ map fixRPOpPrec rps)
-- Template Haskell
SpliceExp l e -> return $ PSplice l e
QuasiQuote l n q -> return $ PQuasiQuote l n q
-- BangPatterns
BangPat l e -> do
p <- checkPat e []
return $ PBangPat l p
PreOp l (QVarOp _ (UnQual _ (Symbol _ "!"))) e -> do
checkEnabled BangPatterns
p <- checkPat e []
return $ PBangPat l p
e -> patFail $ prettyPrint e
checkPat e _ = patFail $ prettyPrint e
isNegatableLiteral :: Literal a -> Bool
isNegatableLiteral (Int _ _ _) = True
isNegatableLiteral (Frac _ _ _) = True
isNegatableLiteral (PrimInt _ _ _) = True
isNegatableLiteral (PrimFloat _ _ _) = True
isNegatableLiteral (PrimDouble _ _ _) = True
isNegatableLiteral _ = False
splitBang :: PExp L -> [PExp L] -> (PExp L, [PExp L])
splitBang (App _ f x) es = splitBang f (x:es)
splitBang e es = (e, es)
checkPatField :: PFieldUpdate L -> P (PatField L)
checkPatField (FieldUpdate l n e) = do
p <- checkPat e []
return (PFieldPat l n p)
checkPatField (FieldPun l n) = return (PFieldPun l n)
checkPatField (FieldWildcard l) = return (PFieldWildcard l)
checkPAttr :: ParseXAttr L -> P (PXAttr L)
checkPAttr (XAttr l n v) = do p <- checkPat v []
return $ PXAttr l n p
patFail :: String -> P a
patFail s = fail $ "Parse error in pattern: " ++ s
checkRPattern :: PExp L -> P (RPat L)
checkRPattern e' = case e' of
SeqRP l es -> do
rps <- mapM checkRPattern es
return $ RPSeq l rps
PostOp l e op -> do
rpop <- checkRPatOp op
rp <- checkRPattern e
return $ RPOp l rp rpop
GuardRP l e gs -> do
rp <- checkPattern e
return $ RPGuard l rp gs
EitherRP l e1 e2 -> do
rp1 <- checkRPattern e1
rp2 <- checkRPattern e2
return $ RPEither l rp1 rp2
CAsRP l n e -> do
rp <- checkRPattern e
return $ RPCAs l n rp
AsPat l n e -> do
rp <- checkRPattern e
return $ RPAs l n rp
Paren l e -> do
rp <- checkRPattern e
return $ RPParen l rp
_ -> do
p <- checkPattern e'
return $ RPPat (ann p) p
checkRPatOp :: QOp L -> P (RPatOp L)
checkRPatOp o@(QVarOp l (UnQual _ (Symbol _ sym))) =
case sym of
"*" -> return $ RPStar l
"*!" -> return $ RPStarG l
"+" -> return $ RPPlus l
"+!" -> return $ RPPlusG l
"?" -> return $ RPOpt l
"?!" -> return $ RPOptG l
_ -> rpOpFail o
checkRPatOp o = rpOpFail o
rpOpFail :: Pretty a => a -> P b
rpOpFail sym = fail $ "Unrecognized regular pattern operator: " ++ prettyPrint sym
fixRPOpPrec :: RPat L -> RPat L
fixRPOpPrec rp' = case rp' of
RPOp l rp rpop -> fPrecOp rp (flip (RPOp l) rpop)
RPEither l rp1 rp2 -> RPEither l (fixRPOpPrec rp1) (fixRPOpPrec rp2)
RPSeq l rps -> RPSeq l $ map fixRPOpPrec rps
RPCAs l n rp -> RPCAs l n $ fixRPOpPrec rp
RPAs l n rp -> RPAs l n $ fixRPOpPrec rp
RPParen l rp -> RPParen l $ fixRPOpPrec rp
_ -> rp'
where fPrecOp :: RPat L -> (RPat L -> RPat L) -> RPat L
fPrecOp (RPOp l rp rpop) f = fPrecOp rp (f . flip (RPOp l) rpop)
fPrecOp (RPCAs l n rp) f = fPrecAs rp f (RPCAs l n)
fPrecOp (RPAs l n rp) f = fPrecAs rp f (RPAs l n)
fPrecOp rp f = f $ fixRPOpPrec rp
fPrecAs :: RPat L -> (RPat L -> RPat L) -> (RPat L -> RPat L) -> RPat L
fPrecAs (RPCAs l n rp) f g = fPrecAs rp f (g . RPCAs l n)
fPrecAs (RPAs l n rp) f g = fPrecAs rp f (g . RPAs l n)
fPrecAs rp f g = g . f $ fixRPOpPrec rp
mkChildrenPat :: [Pat L] -> [Pat L]
mkChildrenPat ps' = mkCPAux ps' []
where mkCPAux :: [Pat L] -> [Pat L] -> [Pat L]
mkCPAux [] qs = reverse qs
mkCPAux (p:ps) qs = case p of
(PRPat l rps) -> [mkCRP l ps (reverse rps ++ map (\q -> RPPat (ann q) q) qs)]
_ -> mkCPAux ps (p:qs)
mkCRP :: L -> [Pat L] -> [RPat L] -> Pat L
mkCRP l [] rps = PXRPats l $ reverse rps
mkCRP _ (p:ps) rps = case p of
(PXRPats l rqs) -> mkCRP l ps (reverse rqs ++ rps)
_ -> mkCRP (ann p) ps (RPPat (ann p) p : rps)
-----------------------------------------------------------------------------
-- Check Expression Syntax
checkExpr :: PExp L -> P (S.Exp L)
checkExpr e' = case e' of
Var l v -> return $ S.Var l v
OverloadedLabel l v -> return $ S.OverloadedLabel l v
IPVar l v -> return $ S.IPVar l v
Con l c -> return $ S.Con l c
Lit l lit -> return $ S.Lit l lit
InfixApp l e1 op e2 -> check2Exprs e1 e2 (flip (S.InfixApp l) op)
App l e1 e2 -> check2Exprs e1 e2 (S.App l)
NegApp _ (Lit _ (PrimWord _ _ _))
-> fail $ "Parse error: negative primitive word literal: " ++ prettyPrint e'
NegApp l e -> check1Expr e (S.NegApp l)
Lambda loc ps e -> check1Expr e (S.Lambda loc ps)
Let l bs e -> check1Expr e (S.Let l bs)
If l e1 e2 e3 -> check3Exprs e1 e2 e3 (S.If l)
MultiIf l alts -> return (S.MultiIf l alts)
Case l e alts -> do
e1 <- checkExpr e
return (S.Case l e1 alts)
Do l stmts -> checkDo stmts >> return (S.Do l stmts)
MDo l stmts -> checkDo stmts >> return (S.MDo l stmts)
TupleSection l bx mes -> if Nothing `notElem` mes
then checkManyExprs (map fromJust mes) (S.Tuple l bx)
else do checkEnabled TupleSections
mes' <- mapM mCheckExpr mes
return $ S.TupleSection l bx mes'
UnboxedSum l before after e -> S.UnboxedSum l before after <$> checkExpr e
List l es -> checkManyExprs es (S.List l)
ParArray l es -> checkManyExprs es (S.ParArray l)
-- Since we don't parse things as left or right sections, we need to mangle them into that.
Paren l e -> case e of
PostOp _ e1 op -> check1Expr e1 (flip (S.LeftSection l) op)
PreOp _ op e2 -> check1Expr e2 (S.RightSection l op)
_ -> check1Expr e (S.Paren l)
RecConstr l c fields -> do
fields1 <- mapM checkField fields
return (S.RecConstr l c fields1)
RecUpdate l e fields -> do
fields1 <- mapM checkField fields
e1 <- checkExpr e
return (S.RecUpdate l e1 fields1)
EnumFrom l e -> check1Expr e (S.EnumFrom l)
EnumFromTo l e1 e2 -> check2Exprs e1 e2 (S.EnumFromTo l)
EnumFromThen l e1 e2 -> check2Exprs e1 e2 (S.EnumFromThen l)
EnumFromThenTo l e1 e2 e3 -> check3Exprs e1 e2 e3 (S.EnumFromThenTo l)
ParArrayFromTo l e1 e2 -> check2Exprs e1 e2 (S.ParArrayFromTo l)
ParArrayFromThenTo l e1 e2 e3 -> check3Exprs e1 e2 e3 (S.ParArrayFromThenTo l)
-- a parallel list comprehension, which could be just a simple one
ParComp l e qualss -> do
e1 <- checkExpr e
case qualss of
[quals] -> return (S.ListComp l e1 quals)
_ -> return (S.ParComp l e1 qualss)
ParArrayComp l e qualss -> do
e1 <- checkExpr e
return (S.ParArrayComp l e1 qualss)
ExpTypeSig loc e ty -> do
e1 <- checkExpr e
return (S.ExpTypeSig loc e1 ty)
--Template Haskell
BracketExp l e -> return $ S.BracketExp l e
SpliceExp l e -> return $ S.SpliceExp l e
TypQuote l q -> return $ S.TypQuote l q
VarQuote l q -> return $ S.VarQuote l q
QuasiQuote l n q -> return $ S.QuasiQuote l n q
-- Hsx
XTag l n attrs mattr cs -> do attrs1 <- mapM checkAttr attrs
cs1 <- mapM checkExpr cs
mattr1 <- maybe (return Nothing)
(\e -> checkExpr e >>= return . Just)
mattr
return $ S.XTag l n attrs1 mattr1 cs1
XETag l n attrs mattr -> do attrs1 <- mapM checkAttr attrs
mattr1 <- maybe (return Nothing)
(\e -> checkExpr e >>= return . Just)
mattr
return $ S.XETag l n attrs1 mattr1
XPcdata l p -> return $ S.XPcdata l p
XExpTag l e -> do e1 <- checkExpr e
return $ S.XExpTag l e1
XChildTag l es -> do es1 <- mapM checkExpr es
return $ S.XChildTag l es1
-- Pragmas
CorePragma l s e -> check1Expr e (S.CorePragma l s)
SCCPragma l s e -> check1Expr e (S.SCCPragma l s)
GenPragma l s xx yy e -> check1Expr e (S.GenPragma l s xx yy)
-- UnknownExpPragma n s -> return $ S.UnknownExpPragma n s
-- Arrows
Proc l p e -> do e1 <- checkExpr e
return $ S.Proc l p e1
LeftArrApp l e1 e2 -> check2Exprs e1 e2 (S.LeftArrApp l)
RightArrApp l e1 e2 -> check2Exprs e1 e2 (S.RightArrApp l)
LeftArrHighApp l e1 e2 -> check2Exprs e1 e2 (S.LeftArrHighApp l)
RightArrHighApp l e1 e2 -> check2Exprs e1 e2 (S.RightArrHighApp l)
ArrOp l e -> S.ArrOp l <$> checkExpr e
-- LamdaCase
LCase l alts -> return $ S.LCase l alts
-- Hole
TypeApp l ty -> return $ S.TypeApp l ty
_ -> fail $ "Parse error in expression: " ++ prettyPrint e'
checkAttr :: ParseXAttr L -> P (S.XAttr L)
checkAttr (XAttr l n v) = do v' <- checkExpr v
return $ S.XAttr l n v'
checkDo :: [Stmt t] -> P ()
checkDo [] = fail "Parse error: Last statement in a do-block must be an expression"
checkDo [Qualifier _ _] = return ()
checkDo (_:xs) = checkDo xs
-- type signature for polymorphic recursion!!
check1Expr :: PExp L -> (S.Exp L -> a) -> P a
check1Expr e1 f = do
e1' <- checkExpr e1
return (f e1')
check2Exprs :: PExp L -> PExp L -> (S.Exp L -> S.Exp L -> a) -> P a
check2Exprs e1 e2 f = do
e1' <- checkExpr e1
e2' <- checkExpr e2
return (f e1' e2')
check3Exprs :: PExp L -> PExp L -> PExp L -> (S.Exp L -> S.Exp L -> S.Exp L -> a) -> P a
check3Exprs e1 e2 e3 f = do
e1' <- checkExpr e1
e2' <- checkExpr e2
e3' <- checkExpr e3
return (f e1' e2' e3')
checkManyExprs :: [PExp L] -> ([S.Exp L] -> a) -> P a
checkManyExprs es f = do
es' <- mapM checkExpr es
return (f es')
mCheckExpr :: Maybe (PExp L) -> P (Maybe (S.Exp L))
mCheckExpr Nothing = return Nothing
mCheckExpr (Just e) = checkExpr e >>= return . Just
checkRuleExpr :: PExp L -> P (S.Exp L)
checkRuleExpr = checkExpr
readTool :: Maybe String -> Maybe Tool
readTool = fmap readC
where readC str = case str of
"GHC" -> GHC
"HUGS" -> HUGS
"NHC98" -> NHC98
"YHC" -> YHC
"HADDOCK" -> HADDOCK
_ -> UnknownTool str
checkField :: PFieldUpdate L -> P (S.FieldUpdate L)
checkField (FieldUpdate l n e) = check1Expr e (S.FieldUpdate l n)
checkField (FieldPun l n) = return $ S.FieldPun l n
checkField (FieldWildcard l) = return $ S.FieldWildcard l
getGConName :: S.Exp L -> P (QName L)
getGConName (S.Con _ n) = return n
getGConName (S.List l []) = return (list_cons_name l)
getGConName _ = fail "Expression in reification is not a name"
-----------------------------------------------------------------------------
-- Check Equation Syntax
checkValDef :: L -> PExp L -> Maybe (S.Type L, S) -> Rhs L -> Maybe (Binds L) -> P (Decl L)
checkValDef l lhs optsig rhs whereBinds = do
mlhs <- isFunLhs lhs []
let whpt = srcInfoPoints l
case mlhs of
Just (f,es,b,pts) -> do
ps <- mapM checkPattern es
let l' = l { srcInfoPoints = pts ++ whpt }
case optsig of -- only pattern bindings can have signatures
Nothing -> return (FunBind l $
if b then [Match l' f ps rhs whereBinds]
else let (a:bs) = ps
in [InfixMatch l' a f bs rhs whereBinds])
Just _ -> fail "Cannot give an explicit type signature to a function binding"
Nothing -> do
lhs1 <- checkPattern lhs
let lhs' = case optsig of
Nothing -> lhs1
Just (ty, pt) -> let lp = (ann lhs1 <++> ann ty) <** [pt]
in PatTypeSig lp lhs1 ty
return (PatBind l lhs' rhs whereBinds)
-- A variable binding is parsed as a PatBind.
isFunLhs :: PExp L -> [PExp L] -> P (Maybe (Name L, [PExp L], Bool, [S]))
isFunLhs (InfixApp _ l (QVarOp loc (UnQual _ op)) r) es
| op =~= Symbol () "!" = do
exts <- getExtensions
if BangPatterns `elem` exts
then let (b,bs) = splitBang r []
loc' = combSpanInfo loc (ann b)
in isFunLhs l (BangPat loc' b : bs ++ es)
else return $ Just (op, l:r:es, False, []) -- It's actually a definition of the operator !
| otherwise =
let infos = srcInfoPoints loc
op' = amap (\s -> s { srcInfoPoints = infos }) op
in (return $ Just (op', l:r:es, False, []))
isFunLhs (App _ (Var l (UnQual _ f)) e) es = return $ Just (f, e:es, True, srcInfoPoints l)
isFunLhs (App _ f e) es = isFunLhs f (e:es)
isFunLhs (Var _ (UnQual _ f)) es@(_:_) = return $ Just (f, es, True, [])
isFunLhs (Paren l f) es@(_:_) = do mlhs <- isFunLhs f es
case mlhs of
Just (f',es',b,pts) ->
let [x,y] = srcInfoPoints l
in return $ Just (f',es',b,x:pts++[y])
_ -> return Nothing
isFunLhs _ _ = return Nothing
-- Separating between signature declarations and value definitions in
-- a post-processing step
checkSigVar :: PExp L -> P (Name L)
checkSigVar (Var _ (UnQual l n)) = return $ fmap (const l) n
checkSigVar e = fail $ "Left-hand side of type signature is not a variable: " ++ prettyPrint e
checkExplicitPatSyn :: S -> S -> ([Decl L], [S]) -> S -> P (PatternSynDirection L)
checkExplicitPatSyn whereLoc openLoc (decls, semis) closeLoc =
let l = whereLoc <^^> closeLoc <** ([whereLoc, openLoc] ++ semis ++ [closeLoc])
in S.ExplicitBidirectional l <$> mapM checkDecls decls
where
checkDecls :: Decl L -> P (Decl L)
checkDecls p@(PatBind _ pat _ _) =
case pat of
PApp _ _ _ -> return p
PInfixApp _ _ _ _ -> return p
_ -> fail "Illegal pattern binding in PatternSynonym"
checkDecls _ = fail "pattern synonym 'where' clause must contain a PatBind"
-----------------------------------------------------------------------------
-- In a class or instance body, a pattern binding must be of a variable.
checkClassBody :: [ClassDecl L] -> P [ClassDecl L]
checkClassBody decls = do
mapM_ checkClassMethodDef decls
return decls
where checkClassMethodDef (ClsDecl _ decl) = checkMethodDef decl
checkClassMethodDef _ = return ()
checkInstBody :: [InstDecl L] -> P [InstDecl L]
checkInstBody decls = do
mapM_ checkInstMethodDef decls
return decls
where checkInstMethodDef (InsDecl _ decl) = checkMethodDef decl
checkInstMethodDef _ = return ()
checkMethodDef :: Decl L -> P ()
checkMethodDef (PatBind _ (PVar _ _) _ _) = return ()
checkMethodDef (PatBind loc _ _ _) =
fail "illegal method definition" `atSrcLoc` fromSrcInfo loc
checkMethodDef _ = return ()
checkDefSigDef :: Decl L -> P (Name L,S.Type L,S)
checkDefSigDef (TypeSig loc [name] typ) =
let (b:_) = srcInfoPoints loc in return (name,typ,b)
checkDefSigDef (TypeSig _ _ _) =
fail "default signature must be for a single name"
checkDefSigDef _ =
fail "default signature must be a type signature"
-----------------------------------------------------------------------------
-- Check that an identifier or symbol is unqualified.
-- For occasions when doing this in the grammar would cause conflicts.
checkUnQual :: QName L -> P (Name L)
checkUnQual (Qual _ _ _) = fail "Illegal qualified name"
checkUnQual (UnQual l n) = return $ fmap (const l) n
checkUnQual (Special _ _) = fail "Illegal special name"
checkQualOrUnQual :: QName L -> P (QName L)
checkQualOrUnQual n@(Qual _ _ _) = return n
checkQualOrUnQual n@(UnQual _ _) = return n
checkQualOrUnQual (Special _ _) = fail "Illegal special name"
-----------------------------------------------------------------------------
-- Check that two xml tag names are equal
checkEqNames :: XName L -> XName L -> P (XName L)
checkEqNames n@(XName _ n1) (XName _ n2)
| n1 == n2 = return n
checkEqNames n@(XDomName _ d1 n1) (XDomName _ d2 n2)
| n1 == n2 && d1 == d2 = return n
checkEqNames n m = fail $ "opening tag '" ++ showTag n ++
"' does not match closing tag '" ++ showTag m ++ "'"
where
showTag (XName _ n') = n'
showTag (XDomName _ d n') = d ++ ":" ++ n'
-----------------------------------------------------------------------------
-- Miscellaneous utilities
checkPrec :: Integer -> P Int
checkPrec i | 0 <= i && i <= 9 = return (fromInteger i)
| otherwise = fail ("Illegal precedence " ++ show i)
mkRecConstrOrUpdate :: PExp L -> [PFieldUpdate L] -> P (PExp L)
mkRecConstrOrUpdate (Con l c) fs = return (RecConstr l c fs)
mkRecConstrOrUpdate e fs@(_:_) = return (RecUpdate (ann e) e fs)
mkRecConstrOrUpdate _ _ = fail "Empty record update"
updateQNameLoc :: l -> QName l -> QName l
updateQNameLoc l (Qual _ mn n) = Qual l mn n
updateQNameLoc l (UnQual _ n) = UnQual l n
updateQNameLoc l (Special _ s) = Special l s
-----------------------------------------------------------------------------
-- For standalone top level Decl parser, check that we actually only
-- parsed one Decl. This is needed since we parse matches of the same
-- FunBind as multiple separate declarations, and merge them after.
-- This should be called *after* checkRevDecls.
checkSingleDecl :: [Decl L] -> P (Decl L)
checkSingleDecl [d] = return d
checkSingleDecl ds =
fail $ "Expected a single declaration, found " ++ show (length ds)
-- Reverse a list of declarations, merging adjacent FunBinds of the
-- same name and checking that their arities match.
checkRevDecls :: [Decl L] -> P [Decl L]
checkRevDecls = mergeFunBinds []
where
mergeFunBinds revDs [] = return revDs
mergeFunBinds revDs (FunBind l' ms1@(Match _ name ps _ _:_):ds1) =
mergeMatches ms1 ds1 l'
where
arity = length ps
mergeMatches ms' (FunBind _ ms@(Match loc name' ps' _ _:_):ds) l
| name' =~= name = do
ignoreArity <- getIgnoreFunctionArity
if length ps' == arity || ignoreArity
then mergeMatches (ms++ms') ds (loc <++> l)
else fail ("arity mismatch for '" ++ prettyPrint name ++ "'")
`atSrcLoc` fromSrcInfo loc
mergeMatches ms' ds l = mergeFunBinds (FunBind l ms':revDs) ds
mergeFunBinds revDs (FunBind l' ims1@(InfixMatch _ _ name _ _ _:_):ds1) =
mergeInfix ims1 ds1 l'
where
mergeInfix ims' (FunBind _ ims@(InfixMatch loc _ name' _ _ _:_):ds) l
| name' =~= name =
mergeInfix (ims++ims') ds (loc <++> l)
mergeInfix ms' ds l = mergeFunBinds (FunBind l ms':revDs) ds
mergeFunBinds revDs (d:ds) = mergeFunBinds (d:revDs) ds
checkRevClsDecls :: [ClassDecl L] -> P [ClassDecl L]
checkRevClsDecls = mergeClsFunBinds []
where
mergeClsFunBinds revDs [] = return revDs