{-# OPTIONS_GHC -fglasgow-exts #-}
module Pugs.Parser.Util where
import Pugs.Internals
import Pugs.AST
import Pugs.Types
import Pugs.Lexer
import Pugs.Rule
import Pugs.Parser.Types
import qualified Data.Map as Map
fixities :: [String]
fixities = ["prefix_circumfix_meta_operator:","infix_circumfix_meta_operator:","prefix_postfix_meta_operator:","postfix_prefix_meta_operator:","infix_postfix_meta_operator:","statement_modifier:","statement_control:","scope_declarator:","trait_auxiliary:","trait_verb:","regex_mod_external:","regex_mod_internal:","regex_assertion:","regex_backslash:","regex_metachar:","postcircumfix:","circumfix:","postfix:","infix:","prefix:","quote:","term:"]
-- around a block body we save the package and the current lexical pad
-- at the start, so that they can be restored after parsing the body
localEnv :: RuleParser Exp -> RuleParser Exp
localEnv m = do
state <- get
let env = ruleEnv state
put state
{ ruleBlockPads = Map.empty
, ruleEnv = env { envOuter = Just env }
}
rv <- m
state' <- get
put state
{ ruleEnv = (ruleEnv state')
{ envPackage = envPackage env
, envLexical = envLexical env
, envOuter = envOuter env
}
}
-- Hoist all pad-declared entries into this block
-- XXX - Handle "state" and "constant" here.
return $ Map.foldWithKey Pad rv (ruleBlockPads state')
ruleParamList :: ParensOption -> RuleParser a -> RuleParser (Maybe [[a]])
ruleParamList wantParens parse = rule "parameter list" $ do
(formal, hasParens) <- f $
(((try parse) `sepEndBy` ruleComma) `sepEndBy` invColon)
case formal of
[[]] -> return $ if hasParens then Just [[], []] else Nothing
[args] -> return $ Just [[], args]
[_,_] -> return $ Just formal
_ -> fail "Only one invocant list allowed"
where
f = case wantParens of
ParensOptional -> maybeParensBool
ParensMandatory -> \x -> do rv <- parens x; return (rv, True)
invColon = do
string ":"
-- Compare:
-- sub foo (: $a) # vs.
-- sub foo (:$a)
lookAhead $ (many1 space <|> string ")")
whiteSpace
return ":"
maybeParensBool :: RuleParser a -> RuleParser (a, Bool)
maybeParensBool p = choice
[ do rv <- parens p; return (rv, True)
, do rv <- p; return (rv, False)
]
isOperatorName :: String -> Bool
isOperatorName ('&':name) = any hasOperatorPrefix [name, tail name]
where
hasOperatorPrefix :: String -> Bool
hasOperatorPrefix name = any (`isPrefixOf` name) fixities
isOperatorName _ = False
{-| Wraps a call to @&Pugs::Internals::check_for_io_leak@ around the input
expression. @&Pugs::Internals::check_for_io_leak@ should @die()@ if the
expression returned an IO handle. -}
-- Please remember to edit Prelude.pm, too, if you rename the name of the
-- checker function.
checkForIOLeak :: Exp -> Exp
checkForIOLeak exp =
App (Var "&Pugs::Internals::check_for_io_leak") Nothing
[ Val $ VCode mkSub { subBody = exp } ]
defaultParamFor :: SubType -> [Param]
defaultParamFor SubBlock = [defaultScalarParam]
defaultParamFor SubPointy = []
defaultParamFor _ = [defaultArrayParam]
doExtract :: SubType -> Maybe [Param] -> Exp -> (Exp, [String], [Param])
doExtract SubBlock formal body = (fun, names', params)
where
(fun, names) = extractPlaceholderVars body []
names' | isJust formal
= filter (/= "$_") names
| otherwise
= names
params = map nameToParam (sort names') ++ (maybe [] id formal)
doExtract SubPointy formal body = (body, [], maybe [] id formal)
doExtract SubMethod formal body = (body, [], maybe [] id formal)
doExtract _ formal body = (body, names', params)
where
(_, names) = extractPlaceholderVars body []
names' | isJust formal
= filter (/= "$_") names
| otherwise
= filter (== "$_") names
params = map nameToParam (sort names') ++ (maybe [] id formal)
nameToParam :: String -> Param
nameToParam name = MkParam
{ isInvocant = False
, isOptional = False
, isNamed = False
, isLValue = True
, isWritable = (name == "$_")
, isLazy = False
, paramName = name
, paramContext = case name of
-- "$_" -> CxtSlurpy $ typeOfSigil (head name)
_ -> CxtItem $ typeOfSigil (head name)
, paramDefault = Noop
}
paramsFor :: SubType -> Maybe [Param] -> [Param] -> [Param]
paramsFor SubMethod formal params
| isNothing (find (("%_" ==) . paramName) params)
= paramsFor SubRoutine formal params ++ [defaultHashParam]
paramsFor styp Nothing [] = defaultParamFor styp
paramsFor _ _ params = params
processFormals :: Monad m => [[Exp]] -> m (Maybe Exp, [Exp])
processFormals formal = case formal of
[] -> return (Nothing, [])
[args] -> return (Nothing, unwind args)
[invs,args] | [inv] <- unwind invs -> return (Just inv, unwind args)
_ -> fail "Only one invocant allowed"
where
unwind :: [Exp] -> [Exp]
unwind [] = []
unwind ((Syn "," list):xs) = unwind list ++ unwind xs
unwind x = x
-- | A Param representing the default (unnamed) invocant of a method on the given type.
selfParam :: String -> Param
selfParam typ = MkParam
{ isInvocant = True
, isOptional = False
, isNamed = False
, isLValue = True
, isWritable = True
, isLazy = False
, paramName = "$?SELF"
, paramContext = CxtItem (mkType typ)
, paramDefault = Noop
}
extractHash :: Exp -> Maybe Exp
extractHash exp = extractHash' (possiblyUnwrap exp)
where
possiblyUnwrap (Syn "block" [exp]) = exp
possiblyUnwrap (App (Val (VCode (MkCode { subType = SubBlock, subBody = fun }))) Nothing []) = fun
possiblyUnwrap x = x
isHashOrPair (Ann _ exp) = isHashOrPair exp
isHashOrPair (App (Var "&pair") _ _) = True
isHashOrPair (App (Var "&infix:=>") _ _) = True
isHashOrPair (Var ('%':_)) = True
isHashOrPair (Syn "%{}" _) = True
isHashOrPair _ = False
extractHash' (Ann _ exp) = extractHash' exp
extractHash' exp | isHashOrPair exp = Just exp
extractHash' exp@(Syn "," (subexp:_)) | isHashOrPair subexp = Just exp
extractHash' exp@Noop = Just exp
extractHash' _ = Nothing