GHC.Parser.Lexer

Documentation

data Token

Constructors

ITas

ITcase

ITclass

ITdata

ITdefault

ITderiving

ITdo (Maybe FastString)

ITelse

IThiding

ITforeign

ITif

ITimport

ITin

ITinfix

ITinfixl

ITinfixr

ITinstance

ITlet

ITmodule

ITnewtype

ITof

ITqualified

ITthen

ITtype

ITwhere

ITforall IsUnicodeSyntax

ITexport

ITlabel

ITdynamic

ITsafe

ITinterruptible

ITunsafe

ITstdcallconv

ITccallconv

ITcapiconv

ITprimcallconv

ITjavascriptcallconv

ITmdo (Maybe FastString)

ITfamily

ITrole

ITgroup

ITby

ITusing

ITpattern

ITstatic

ITstock

ITanyclass

ITvia

ITunit

ITsignature

ITdependency

ITrequires

ITinline_prag SourceText InlineSpec RuleMatchInfo

ITopaque_prag SourceText

ITspec_prag SourceText

ITspec_inline_prag SourceText Bool

ITsource_prag SourceText

ITrules_prag SourceText

ITwarning_prag SourceText

ITdeprecated_prag SourceText

ITline_prag SourceText

ITcolumn_prag SourceText

ITscc_prag SourceText

ITunpack_prag SourceText

ITnounpack_prag SourceText

ITann_prag SourceText

ITcomplete_prag SourceText

ITclose_prag

IToptions_prag String

ITinclude_prag String

ITlanguage_prag

ITminimal_prag SourceText

IToverlappable_prag SourceText

IToverlapping_prag SourceText

IToverlaps_prag SourceText

ITincoherent_prag SourceText

ITctype SourceText

ITcomment_line_prag

ITdotdot

ITcolon

ITdcolon IsUnicodeSyntax

ITequal

ITlam

ITlcase

ITlcases

ITvbar

ITlarrow IsUnicodeSyntax

ITrarrow IsUnicodeSyntax

ITdarrow IsUnicodeSyntax

ITlolly

ITminus

ITprefixminus

ITbang

ITtilde

ITat

ITtypeApp

ITpercent

ITstar IsUnicodeSyntax

ITdot

ITproj Bool

ITbiglam

ITocurly

ITccurly

ITvocurly

ITvccurly

ITobrack

ITopabrack

ITcpabrack

ITcbrack

IToparen

ITcparen

IToubxparen

ITcubxparen

ITsemi

ITcomma

ITunderscore

ITbackquote

ITsimpleQuote

ITvarid FastString

ITconid FastString

ITvarsym FastString

ITconsym FastString

ITqvarid (FastString, FastString)

ITqconid (FastString, FastString)

ITqvarsym (FastString, FastString)

ITqconsym (FastString, FastString)

ITdupipvarid FastString

ITlabelvarid FastString

ITchar SourceText Char

ITstring SourceText FastString

ITinteger IntegralLit

ITrational FractionalLit

ITprimchar SourceText Char

ITprimstring SourceText ByteString

ITprimint SourceText Integer

ITprimword SourceText Integer

ITprimfloat FractionalLit

ITprimdouble FractionalLit

ITopenExpQuote HasE IsUnicodeSyntax

ITopenPatQuote

ITopenDecQuote

ITopenTypQuote

ITcloseQuote IsUnicodeSyntax

ITopenTExpQuote HasE

ITcloseTExpQuote

ITdollar

ITdollardollar

ITtyQuote

ITquasiQuote (FastString, FastString, PsSpan)

ITqQuasiQuote (FastString, FastString, FastString, PsSpan)

ITproc

ITrec

IToparenbar IsUnicodeSyntax

(|

ITcparenbar IsUnicodeSyntax

|)

ITlarrowtail IsUnicodeSyntax

-<

ITrarrowtail IsUnicodeSyntax

>-

ITLarrowtail IsUnicodeSyntax

-<<

ITRarrowtail IsUnicodeSyntax

>>-

ITunknown String

Used when the lexer can't make sense of it

ITeof

end of file token

ITdocComment HsDocString PsSpan

The HsDocString contains more details about what this is and how to pretty print it

ITdocOptions String PsSpan

doc options (prune, ignore-exports, etc)

ITlineComment String PsSpan

comment starting by "--"

ITblockComment String PsSpan

comment in {- -}

Instances

Show Token

Defined in GHC.Parser.Lexer

Methods

showsPrec :: Int -> Token -> ShowS

show :: Token -> String

showList :: [Token] -> ShowS

Outputable Token

Defined in GHC.Parser.Lexer

Methods

ppr :: Token -> SDoc

lexer :: Bool -> (Located Token -> P a) -> P a

lexerDbg :: Bool -> (Located Token -> P a) -> P a

data ParserOpts

Parser options.

See mkParserOpts to construct this.

Constructors

ParserOpts

Fields

• pExtsBitmap :: !ExtsBitmap

  bitmap of permitted extensions

• pDiagOpts :: !DiagOpts

  Options to construct diagnostic messages.

• pSupportedExts :: [String]

  supported extensions (only used for suggestions in error messages)

mkParserOpts

Arguments

:: EnumSet Extension

permitted language extensions enabled

-> DiagOpts

diagnostic options

-> [String]

Supported Languages and Extensions

-> Bool

are safe imports on?

-> Bool

keeping Haddock comment tokens

-> Bool

keep regular comment tokens

-> Bool

If this is enabled, '{-# LINE ... -#}' and '{-# COLUMN ... #-}' update the internal position kept by the parser. Otherwise, those pragmas are lexed as ITline_prag and ITcolumn_prag tokens.

-> ParserOpts

Given exactly the information needed, set up the ParserOpts

data PState

Constructors

PState

Fields

• buffer :: StringBuffer
• options :: ParserOpts
• warnings :: Messages PsMessage
• errors :: Messages PsMessage
• tab_first :: Maybe RealSrcSpan
• tab_count :: !Word
• last_tk :: Maybe (PsLocated Token)
• prev_loc :: PsSpan
• prev_loc2 :: PsSpan
• last_loc :: PsSpan
• last_len :: !Int
• loc :: PsLoc
• context :: [LayoutContext]
• lex_state :: [Int]
• srcfiles :: [FastString]
• alr_pending_implicit_tokens :: [PsLocated Token]
• alr_next_token :: Maybe (PsLocated Token)
• alr_last_loc :: PsSpan
• alr_context :: [ALRContext]
• alr_expecting_ocurly :: Maybe ALRLayout
• alr_justClosedExplicitLetBlock :: Bool
• eof_pos :: Maybe (Pair RealSrcSpan RealSrcSpan)
• header_comments :: Maybe [LEpaComment]
• comment_q :: [LEpaComment]
• hdk_comments :: OrdList (PsLocated HdkComment)

initParserState :: ParserOpts -> StringBuffer -> RealSrcLoc -> PState

Creates a parse state from a ParserOpts value

initPragState :: ParserOpts -> StringBuffer -> RealSrcLoc -> PState

Set parser options for parsing OPTIONS pragmas

newtype P a

The parsing monad, isomorphic to StateT PState Maybe.

Constructors

P

Fields

• unP :: PState -> ParseResult a

Instances

Applicative P

Defined in GHC.Parser.Lexer

Methods

pure :: a -> P a

(<*>) :: P (a -> b) -> P a -> P b

liftA2 :: (a -> b -> c) -> P a -> P b -> P c

(*>) :: P a -> P b -> P b

(<*) :: P a -> P b -> P a

Functor P

Defined in GHC.Parser.Lexer

Methods

fmap :: (a -> b) -> P a -> P b

(<$) :: a -> P b -> P a

Monad P

Defined in GHC.Parser.Lexer

Methods

(>>=) :: P a -> (a -> P b) -> P b

(>>) :: P a -> P b -> P b

return :: a -> P a

MonadP P

Defined in GHC.Parser.Lexer

Methods

addError :: MsgEnvelope PsMessage -> P ()

addWarning :: MsgEnvelope PsMessage -> P ()

addFatalError :: MsgEnvelope PsMessage -> P a

getBit :: ExtBits -> P Bool

allocateCommentsP :: RealSrcSpan -> P EpAnnComments

allocatePriorCommentsP :: RealSrcSpan -> P EpAnnComments

allocateFinalCommentsP :: RealSrcSpan -> P EpAnnComments

data ParseResult a where

The result of running a parser.

Bundled Patterns

pattern POk :: PState -> a -> ParseResult a

The parser has consumed a (possibly empty) prefix of the input and produced a result. Use getPsMessages to check for accumulated warnings and non-fatal errors.

The carried parsing state can be used to resume parsing.

pattern PFailed :: PState -> ParseResult a

The parser has consumed a (possibly empty) prefix of the input and failed.

The carried parsing state can be used to resume parsing. It is the state right before failure, including the fatal parse error. getPsMessages and getPsErrorMessages must return a non-empty bag of errors.

allocateComments :: RealSrcSpan -> [LEpaComment] -> ([LEpaComment], [LEpaComment])

allocatePriorComments :: RealSrcSpan -> [LEpaComment] -> Maybe [LEpaComment] -> (Maybe [LEpaComment], [LEpaComment], [LEpaComment])

allocateFinalComments :: RealSrcSpan -> [LEpaComment] -> Maybe [LEpaComment] -> (Maybe [LEpaComment], [LEpaComment], [LEpaComment])

class Monad m => MonadP m where

An mtl-style class for monads that support parsing-related operations. For example, sometimes we make a second pass over the parsing results to validate, disambiguate, or rearrange them, and we do so in the PV monad which cannot consume input but can report parsing errors, check for extension bits, and accumulate parsing annotations. Both P and PV are instances of MonadP.

MonadP grants us convenient overloading. The other option is to have separate operations for each monad: addErrorP vs addErrorPV, getBitP vs getBitPV, and so on.

Methods

addError :: MsgEnvelope PsMessage -> m ()

Add a non-fatal error. Use this when the parser can produce a result despite the error.

For example, when GHC encounters a forall in a type, but -XExplicitForAll is disabled, the parser constructs ForAllTy as if -XExplicitForAll was enabled, adding a non-fatal error to the accumulator.

Control flow wise, non-fatal errors act like warnings: they are added to the accumulator and parsing continues. This allows GHC to report more than one parse error per file.

addWarning :: MsgEnvelope PsMessage -> m ()

Add a warning to the accumulator. Use getPsMessages to get the accumulated warnings.

addFatalError :: MsgEnvelope PsMessage -> m a

Add a fatal error. This will be the last error reported by the parser, and the parser will not produce any result, ending in a PFailed state.

getBit :: ExtBits -> m Bool

Check if a given flag is currently set in the bitmap.

allocateCommentsP :: RealSrcSpan -> m EpAnnComments

Go through the comment_q in PState and remove all comments that belong within the given span

allocatePriorCommentsP :: RealSrcSpan -> m EpAnnComments

Go through the comment_q in PState and remove all comments that come before or within the given span

allocateFinalCommentsP :: RealSrcSpan -> m EpAnnComments

Go through the comment_q in PState and remove all comments that come after the given span

Instances

MonadP P

Defined in GHC.Parser.Lexer

Methods

addError :: MsgEnvelope PsMessage -> P ()

addWarning :: MsgEnvelope PsMessage -> P ()

addFatalError :: MsgEnvelope PsMessage -> P a

getBit :: ExtBits -> P Bool

allocateCommentsP :: RealSrcSpan -> P EpAnnComments

allocatePriorCommentsP :: RealSrcSpan -> P EpAnnComments

allocateFinalCommentsP :: RealSrcSpan -> P EpAnnComments

MonadP PV

Defined in GHC.Parser.PostProcess

Methods

addError :: MsgEnvelope PsMessage -> PV ()

addWarning :: MsgEnvelope PsMessage -> PV ()

addFatalError :: MsgEnvelope PsMessage -> PV a

getBit :: ExtBits -> PV Bool

allocateCommentsP :: RealSrcSpan -> PV EpAnnComments

allocatePriorCommentsP :: RealSrcSpan -> PV EpAnnComments

allocateFinalCommentsP :: RealSrcSpan -> PV EpAnnComments

getRealSrcLoc :: P RealSrcLoc

getPState :: P PState

failMsgP :: (SrcSpan -> MsgEnvelope PsMessage) -> P a

failLocMsgP :: RealSrcLoc -> RealSrcLoc -> (SrcSpan -> MsgEnvelope PsMessage) -> P a

srcParseFail :: P a

getPsErrorMessages :: PState -> Messages PsMessage

Get a bag of the errors that have been accumulated so far. Does not take -Werror into account.

getPsMessages :: PState -> (Messages PsMessage, Messages PsMessage)

Get the warnings and errors accumulated so far. Does not take -Werror into account.

popContext :: P ()

pushModuleContext :: P ()

setLastToken :: PsSpan -> Int -> P ()

setSrcLoc :: RealSrcLoc -> P ()

activeContext :: P Bool

nextIsEOF :: P Bool

getLexState :: P Int

popLexState :: P Int

pushLexState :: Int -> P ()

data ExtBits

Various boolean flags, mostly language extensions, that impact lexing and parsing. Note that a handful of these can change during lexing/parsing.

Constructors

FfiBit

InterruptibleFfiBit

CApiFfiBit

ArrowsBit

ThBit

ThQuotesBit

IpBit

OverloadedLabelsBit

ExplicitForallBit

BangPatBit

PatternSynonymsBit

HaddockBit

MagicHashBit

RecursiveDoBit

QualifiedDoBit

UnicodeSyntaxBit

UnboxedParensBit

DatatypeContextsBit

MonadComprehensionsBit

TransformComprehensionsBit

QqBit

RawTokenStreamBit

AlternativeLayoutRuleBit

ALRTransitionalBit

RelaxedLayoutBit

NondecreasingIndentationBit

SafeHaskellBit

TraditionalRecordSyntaxBit

ExplicitNamespacesBit

LambdaCaseBit

BinaryLiteralsBit

NegativeLiteralsBit

HexFloatLiteralsBit

StaticPointersBit

NumericUnderscoresBit

StarIsTypeBit

BlockArgumentsBit

NPlusKPatternsBit

DoAndIfThenElseBit

MultiWayIfBit

GadtSyntaxBit

ImportQualifiedPostBit

LinearTypesBit

NoLexicalNegationBit

OverloadedRecordDotBit

OverloadedRecordUpdateBit

InRulePragBit

InNestedCommentBit

UsePosPragsBit

If this is enabled, '{-# LINE ... -#}' and '{-# COLUMN ... #-}' update the internal position. Otherwise, those pragmas are lexed as tokens of their own.

Instances

Enum ExtBits

Defined in GHC.Parser.Lexer

Methods

succ :: ExtBits -> ExtBits

pred :: ExtBits -> ExtBits

toEnum :: Int -> ExtBits

fromEnum :: ExtBits -> Int

enumFrom :: ExtBits -> [ExtBits]

enumFromThen :: ExtBits -> ExtBits -> [ExtBits]

enumFromTo :: ExtBits -> ExtBits -> [ExtBits]

enumFromThenTo :: ExtBits -> ExtBits -> ExtBits -> [ExtBits]

xtest :: ExtBits -> ExtsBitmap -> Bool

xunset :: ExtBits -> ExtsBitmap -> ExtsBitmap

xset :: ExtBits -> ExtsBitmap -> ExtsBitmap

disableHaddock :: ParserOpts -> ParserOpts

lexTokenStream :: ParserOpts -> StringBuffer -> RealSrcLoc -> ParseResult [Located Token]

mkParensEpAnn :: RealSrcSpan -> (AddEpAnn, AddEpAnn)

Given a RealSrcSpan that surrounds a HsPar or HsParTy, generate AddEpAnn values for the opening and closing bordering on the start and end of the span

getCommentsFor :: MonadP m => SrcSpan -> m EpAnnComments

getPriorCommentsFor :: MonadP m => SrcSpan -> m EpAnnComments

getFinalCommentsFor :: MonadP m => SrcSpan -> m EpAnnComments

getEofPos :: P (Maybe (Pair RealSrcSpan RealSrcSpan))

commentToAnnotation :: RealLocated Token -> LEpaComment

data HdkComment

Haddock comment as produced by the lexer. These are accumulated in PState and then processed in GHC.Parser.PostProcess.Haddock. The location of the HsDocStrings spans over the contents of the docstring - i.e. it does not include the decorator ("-- |", "{-|" etc.)

Constructors

HdkCommentNext HsDocString

HdkCommentPrev HsDocString

HdkCommentNamed String HsDocString

HdkCommentSection Int HsDocString

Instances

Show HdkComment

Defined in GHC.Parser.Lexer

Methods

showsPrec :: Int -> HdkComment -> ShowS

show :: HdkComment -> String

showList :: [HdkComment] -> ShowS

warnopt :: WarningFlag -> ParserOpts -> Bool

Test whether a WarningFlag is set

adjustChar :: Char -> Word8

addPsMessage :: SrcSpan -> PsMessage -> P ()