X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fparser%2FLexer.x;h=6651333dc4b709821e6a2163afcfd534ba0c295d;hp=edfbecdc91735a8d3c14f3ab96379317c86a9ef6;hb=26f164e5759e9eca73deb0531ddec422d36a6924;hpb=831a35dd00faff195cf938659c2dd736192b865f diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x index edfbecd..6651333 100644 --- a/compiler/parser/Lexer.x +++ b/compiler/parser/Lexer.x @@ -12,7 +12,6 @@ ----------------------------------------------------------------------------- -- ToDo / known bugs: --- - Unicode -- - parsing integers is a bit slow -- - readRational is a bit slow -- @@ -32,23 +31,24 @@ -- qualified varids. { -{-# OPTIONS -Wwarn #-} --- The above warning supression flag is a temporary kludge. --- While working on this module you are encouraged to remove it and fix --- any warnings in the module. See --- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings --- for details --- --- Note that Alex itself generates code with with some unused bindings and --- without type signatures, so removing the flag might not be possible. +-- XXX The above flags turn off warnings in the generated code: +{-# OPTIONS_GHC -fno-warn-unused-matches #-} +{-# OPTIONS_GHC -fno-warn-unused-binds #-} +{-# OPTIONS_GHC -fno-warn-unused-imports #-} +{-# OPTIONS_GHC -fno-warn-missing-signatures #-} +-- But alex still generates some code that causes the "lazy unlifted bindings" +-- warning, and old compilers don't know about it so we can't easily turn +-- it off, so for now we use the sledge hammer: +{-# OPTIONS_GHC -w #-} {-# OPTIONS_GHC -funbox-strict-fields #-} module Lexer ( Token(..), lexer, pragState, mkPState, PState(..), P(..), ParseResult(..), getSrcLoc, + getPState, getDynFlags, withThisPackage, failLocMsgP, failSpanMsgP, srcParseFail, - getMessages, + getMessages, popContext, pushCurrentContext, setLastToken, setSrcLoc, getLexState, popLexState, pushLexState, extension, standaloneDerivingEnabled, bangPatEnabled, @@ -61,18 +61,21 @@ import ErrUtils import Outputable import StringBuffer import FastString -import FastTypes import SrcLoc import UniqFM import DynFlags +import Module import Ctype -import Util ( maybePrefixMatch, readRational ) +import Util ( readRational ) import Control.Monad import Data.Bits import Data.Char +import Data.List +import Data.Maybe +import Data.Map (Map) +import qualified Data.Map as Map import Data.Ratio -import Debug.Trace } $unispace = \x05 -- Trick Alex into handling Unicode. See alexGetChar. @@ -107,6 +110,8 @@ $symchar = [$symbol \:] $nl = [\n\r] $idchar = [$small $large $digit \'] +$pragmachar = [$small $large $digit] + $docsym = [\| \^ \* \$] @varid = $small $idchar* @@ -221,8 +226,8 @@ $tab+ { warn Opt_WarnTabs (text "Tab character") } <0,option_prags> \n { begin bol } -"{-#" $whitechar* (line|LINE) / { notFollowedByPragmaChar } - { begin line_prag2 } +"{-#" $whitechar* $pragmachar+ / { known_pragma linePrags } + { dispatch_pragmas linePrags } -- single-line line pragmas, of the form -- # "" \n @@ -239,69 +244,31 @@ $tab+ { warn Opt_WarnTabs (text "Tab character") } -- with older versions of GHC which generated these. <0,option_prags> { - "{-#" $whitechar* (RULES|rules) / { notFollowedByPragmaChar } { rulePrag } - "{-#" $whitechar* (INLINE|inline) / { notFollowedByPragmaChar } - { token (ITinline_prag True) } - "{-#" $whitechar* (NO(T?)INLINE|no(t?)inline) / { notFollowedByPragmaChar } - { token (ITinline_prag False) } - "{-#" $whitechar* (INLINE|inline) - $whitechar+ (CONLIKE|conlike) / { notFollowedByPragmaChar } - { token (ITinline_conlike_prag True) } - "{-#" $whitechar* (NO(T)?INLINE|no(t?)inline) - $whitechar+ (CONLIKE|constructorlike) / { notFollowedByPragmaChar } - { token (ITinline_conlike_prag False) } - "{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e) / { notFollowedByPragmaChar } - { token ITspec_prag } - "{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e) - $whitechar+ (INLINE|inline) / { notFollowedByPragmaChar } - { token (ITspec_inline_prag True) } - "{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e) - $whitechar+ (NO(T?)INLINE|no(t?)inline) / { notFollowedByPragmaChar } - { token (ITspec_inline_prag False) } - "{-#" $whitechar* (SOURCE|source) / { notFollowedByPragmaChar } - { token ITsource_prag } - "{-#" $whitechar* (WARNING|warning) / { notFollowedByPragmaChar } - { token ITwarning_prag } - "{-#" $whitechar* (DEPRECATED|deprecated) / { notFollowedByPragmaChar } - { token ITdeprecated_prag } - "{-#" $whitechar* (SCC|scc) / { notFollowedByPragmaChar } - { token ITscc_prag } - "{-#" $whitechar* (GENERATED|generated) / { notFollowedByPragmaChar } - { token ITgenerated_prag } - "{-#" $whitechar* (CORE|core) / { notFollowedByPragmaChar } - { token ITcore_prag } - "{-#" $whitechar* (UNPACK|unpack) / { notFollowedByPragmaChar } - { token ITunpack_prag } - "{-#" $whitechar* (ANN|ann) / { notFollowedByPragmaChar } - { token ITann_prag } + "{-#" $whitechar* $pragmachar+ + $whitechar+ $pragmachar+ / { known_pragma twoWordPrags } + { dispatch_pragmas twoWordPrags } + + "{-#" $whitechar* $pragmachar+ / { known_pragma oneWordPrags } + { dispatch_pragmas oneWordPrags } -- We ignore all these pragmas, but don't generate a warning for them - -- CFILES is a hugs-only thing. - "{-#" $whitechar* (OPTIONS_(HUGS|hugs|NHC98|nhc98|JHC|jhc|YHC|yhc|CATCH|catch|DERIVE|derive)|CFILES|cfiles|CONTRACT|contract) / { notFollowedByPragmaChar } - { nested_comment lexToken } + "{-#" $whitechar* $pragmachar+ / { known_pragma ignoredPrags } + { dispatch_pragmas ignoredPrags } -- ToDo: should only be valid inside a pragma: "#-}" { endPrag } } { - "{-#" $whitechar* (OPTIONS|options) / { notFollowedByPragmaChar } - { lex_string_prag IToptions_prag } - "{-#" $whitechar* (OPTIONS_GHC|options_ghc) / { notFollowedByPragmaChar } - { lex_string_prag IToptions_prag } - "{-#" $whitechar* (OPTIONS_HADDOCK|options_haddock) - / { notFollowedByPragmaChar } - { lex_string_prag ITdocOptions } + "{-#" $whitechar* $pragmachar+ / { known_pragma fileHeaderPrags } + { dispatch_pragmas fileHeaderPrags } + "-- #" { multiline_doc_comment } - "{-#" $whitechar* (LANGUAGE|language) / { notFollowedByPragmaChar } - { token ITlanguage_prag } - "{-#" $whitechar* (INCLUDE|include) / { notFollowedByPragmaChar } - { lex_string_prag ITinclude_prag } } <0> { -- In the "0" mode we ignore these pragmas - "{-#" $whitechar* (OPTIONS|options|OPTIONS_GHC|options_ghc|OPTIONS_HADDOCK|options_haddock|LANGUAGE|language|INCLUDE|include) / { notFollowedByPragmaChar } + "{-#" $whitechar* $pragmachar+ / { known_pragma fileHeaderPrags } { nested_comment lexToken } } @@ -340,7 +307,7 @@ $tab+ { warn Opt_WarnTabs (text "Tab character") } \$ @varid / { ifExtension thEnabled } { skip_one_varid ITidEscape } "$(" / { ifExtension thEnabled } { token ITparenEscape } - "[$" @varid "|" / { ifExtension qqEnabled } + "[" @varid "|" / { ifExtension qqEnabled } { lex_quasiquote_tok } } @@ -487,7 +454,7 @@ data Token | ITunsafe | ITstdcallconv | ITccallconv - | ITdotnet + | ITprimcallconv | ITmdo | ITfamily | ITgroup @@ -564,8 +531,6 @@ data Token | ITdupipvarid FastString -- GHC extension: implicit param: ?x - | ITpragma StringBuffer - | ITchar Char | ITstring FastString | ITinteger Integer @@ -578,7 +543,7 @@ data Token | ITprimfloat Rational | ITprimdouble Rational - -- MetaHaskell extension tokens + -- Template Haskell extension tokens | ITopenExpQuote -- [| or [e| | ITopenPatQuote -- [p| | ITopenDecQuote -- [d| @@ -634,6 +599,7 @@ isSpecial ITthreadsafe = True isSpecial ITunsafe = True isSpecial ITccallconv = True isSpecial ITstdcallconv = True +isSpecial ITprimcallconv = True isSpecial ITmdo = True isSpecial ITfamily = True isSpecial ITgroup = True @@ -649,6 +615,7 @@ isSpecial _ = False -- facilitates using a keyword in two different extensions that can be -- activated independently) -- +reservedWordsFM :: UniqFM (Token, Int) reservedWordsFM = listToUFM $ map (\(x, y, z) -> (mkFastString x, (y, z))) [( "_", ITunderscore, 0 ), @@ -690,13 +657,13 @@ reservedWordsFM = listToUFM $ ( "label", ITlabel, bit ffiBit), ( "dynamic", ITdynamic, bit ffiBit), ( "safe", ITsafe, bit ffiBit), - ( "threadsafe", ITthreadsafe, bit ffiBit), + ( "threadsafe", ITthreadsafe, bit ffiBit), -- ToDo: remove ( "unsafe", ITunsafe, bit ffiBit), ( "stdcall", ITstdcallconv, bit ffiBit), ( "ccall", ITccallconv, bit ffiBit), - ( "dotnet", ITdotnet, bit ffiBit), + ( "prim", ITprimcallconv, bit ffiBit), - ( "rec", ITrec, bit arrowsBit), + ( "rec", ITrec, bit recBit), ( "proc", ITproc, bit arrowsBit) ] @@ -735,6 +702,14 @@ reservedSymsFM = listToUFM $ ,("→", ITrarrow, unicodeSyntaxEnabled) ,("←", ITlarrow, unicodeSyntaxEnabled) ,("⋯", ITdotdot, unicodeSyntaxEnabled) + + ,("⤙", ITlarrowtail, \i -> unicodeSyntaxEnabled i && arrowsEnabled i) + ,("⤚", ITrarrowtail, \i -> unicodeSyntaxEnabled i && arrowsEnabled i) + ,("⤛", ITLarrowtail, \i -> unicodeSyntaxEnabled i && arrowsEnabled i) + ,("⤜", ITRarrowtail, \i -> unicodeSyntaxEnabled i && arrowsEnabled i) + + ,("★", ITstar, unicodeSyntaxEnabled) + -- ToDo: ideally, → and ∷ should be "specials", so that they cannot -- form part of a large operator. This would let us have a better -- syntax for kinds: ɑ∷*→* would be a legal kind signature. (maybe). @@ -772,44 +747,50 @@ begin :: Int -> Action begin code _span _str _len = do pushLexState code; lexToken pop :: Action -pop _span _buf _len = do popLexState; lexToken +pop _span _buf _len = do _ <- popLexState + lexToken pop_and :: Action -> Action -pop_and act span buf len = do popLexState; act span buf len +pop_and act span buf len = do _ <- popLexState + act span buf len {-# INLINE nextCharIs #-} +nextCharIs :: StringBuffer -> (Char -> Bool) -> Bool nextCharIs buf p = not (atEnd buf) && p (currentChar buf) -notFollowedBy char _ _ _ (AI _ _ buf) +notFollowedBy :: Char -> AlexAccPred Int +notFollowedBy char _ _ _ (AI _ buf) = nextCharIs buf (/=char) -notFollowedBySymbol _ _ _ (AI _ _ buf) +notFollowedBySymbol :: AlexAccPred Int +notFollowedBySymbol _ _ _ (AI _ buf) = nextCharIs buf (`notElem` "!#$%&*+./<=>?@\\^|-~") -notFollowedByPragmaChar _ _ _ (AI _ _ buf) - = nextCharIs buf (\c -> not (isAlphaNum c || c == '_')) - -- We must reject doc comments as being ordinary comments everywhere. -- In some cases the doc comment will be selected as the lexeme due to -- maximal munch, but not always, because the nested comment rule is -- valid in all states, but the doc-comment rules are only valid in -- the non-layout states. -isNormalComment bits _ _ (AI _ _ buf) +isNormalComment :: AlexAccPred Int +isNormalComment bits _ _ (AI _ buf) | haddockEnabled bits = notFollowedByDocOrPragma | otherwise = nextCharIs buf (/='#') where notFollowedByDocOrPragma = not $ spaceAndP buf (`nextCharIs` (`elem` "|^*$#")) +spaceAndP :: StringBuffer -> (StringBuffer -> Bool) -> Bool spaceAndP buf p = p buf || nextCharIs buf (==' ') && p (snd (nextChar buf)) {- -haddockDisabledAnd p bits _ _ (AI _ _ buf) +haddockDisabledAnd p bits _ _ (AI _ buf) = if haddockEnabled bits then False else (p buf) -} -atEOL _ _ _ (AI _ _ buf) = atEnd buf || currentChar buf == '\n' +atEOL :: AlexAccPred Int +atEOL _ _ _ (AI _ buf) = atEnd buf || currentChar buf == '\n' +ifExtension :: (Int -> Bool) -> AlexAccPred Int ifExtension pred bits _ _ _ = pred bits multiline_doc_comment :: Action @@ -890,14 +871,17 @@ nested_doc_comment span buf _len = withLexedDocType (go "") Just (_,_) -> go ('\123':commentAcc) input docType False Just (c,input) -> go (c:commentAcc) input docType False +withLexedDocType :: (AlexInput -> (String -> Token) -> Bool -> P (Located Token)) + -> P (Located Token) withLexedDocType lexDocComment = do - input@(AI _ _ buf) <- getInput + input@(AI _ buf) <- getInput case prevChar buf ' ' of '|' -> lexDocComment input ITdocCommentNext False '^' -> lexDocComment input ITdocCommentPrev False '$' -> lexDocComment input ITdocCommentNamed False '*' -> lexDocSection 1 input '#' -> lexDocComment input ITdocOptionsOld False + _ -> panic "withLexedDocType: Bad doc type" where lexDocSection n input = case alexGetChar input of Just ('*', input) -> lexDocSection (n+1) input @@ -907,12 +891,12 @@ withLexedDocType lexDocComment = do -- RULES pragmas turn on the forall and '.' keywords, and we turn them -- off again at the end of the pragma. rulePrag :: Action -rulePrag span buf len = do +rulePrag span _buf _len = do setExts (.|. bit inRulePragBit) return (L span ITrules_prag) endPrag :: Action -endPrag span buf len = do +endPrag span _buf _len = do setExts (.&. complement (bit inRulePragBit)) return (L span ITclose_prag) @@ -924,32 +908,21 @@ endPrag span buf len = do -- it writes the wrong token length to the parser state. This function is -- called afterwards, so it can just update the state. --- This is complicated by the fact that Haddock tokens can span multiple lines, --- which is something that the original lexer didn't account for. --- I have added last_line_len in the parser state which represents the length --- of the part of the token that is on the last line. It is now used for layout --- calculation in pushCurrentContext instead of last_len. last_len is, like it --- was before, the full length of the token, and it is now only used for error --- messages. /Waern - docCommentEnd :: AlexInput -> String -> (String -> Token) -> StringBuffer -> SrcSpan -> P (Located Token) docCommentEnd input commentAcc docType buf span = do setInput input - let (AI loc last_offs nextBuf) = input + let (AI loc nextBuf) = input comment = reverse commentAcc span' = mkSrcSpan (srcSpanStart span) loc last_len = byteDiff buf nextBuf - last_line_len = if (last_offs - last_len < 0) - then last_offs - else last_len - - span `seq` setLastToken span' last_len last_line_len + span `seq` setLastToken span' last_len return (L span' (docType comment)) -errBrace (AI end _ _) span = failLocMsgP (srcSpanStart span) end "unterminated `{-'" - +errBrace :: AlexInput -> SrcSpan -> P a +errBrace (AI end _) span = failLocMsgP (srcSpanStart span) end "unterminated `{-'" + open_brace, close_brace :: Action open_brace span _str _len = do ctx <- getContext @@ -959,6 +932,7 @@ close_brace span _str _len = do popContext return (L span ITccurly) +qvarid, qconid :: StringBuffer -> Int -> Token qvarid buf len = ITqvarid $! splitQualName buf len False qconid buf len = ITqconid $! splitQualName buf len False @@ -992,7 +966,8 @@ splitQualName orig_buf len parens = split orig_buf orig_buf where qual_size = orig_buf `byteDiff` dot_buf -varid span buf len = +varid :: Action +varid span buf len = fs `seq` case lookupUFM reservedWordsFM fs of Just (keyword,0) -> do @@ -1007,17 +982,22 @@ varid span buf len = where fs = lexemeToFastString buf len +conid :: StringBuffer -> Int -> Token conid buf len = ITconid fs where fs = lexemeToFastString buf len +qvarsym, qconsym, prefixqvarsym, prefixqconsym :: StringBuffer -> Int -> Token qvarsym buf len = ITqvarsym $! splitQualName buf len False qconsym buf len = ITqconsym $! splitQualName buf len False prefixqvarsym buf len = ITprefixqvarsym $! splitQualName buf len True prefixqconsym buf len = ITprefixqconsym $! splitQualName buf len True +varsym, consym :: Action varsym = sym ITvarsym consym = sym ITconsym +sym :: (FastString -> Token) -> SrcSpan -> StringBuffer -> Int + -> P (Located Token) sym con span buf len = case lookupUFM reservedSymsFM fs of Just (keyword,exts) -> do @@ -1039,16 +1019,27 @@ tok_integral itint transint transbuf translen (radix,char_to_int) span buf len = (offsetBytes transbuf buf) (subtract translen len) radix char_to_int -- some conveniences for use with tok_integral +tok_num :: (Integer -> Integer) + -> Int -> Int + -> (Integer, (Char->Int)) -> Action tok_num = tok_integral ITinteger +tok_primint :: (Integer -> Integer) + -> Int -> Int + -> (Integer, (Char->Int)) -> Action tok_primint = tok_integral ITprimint +tok_primword :: Int -> Int + -> (Integer, (Char->Int)) -> Action tok_primword = tok_integral ITprimword positive +positive, negative :: (Integer -> Integer) positive = id negative = negate +decimal, octal, hexadecimal :: (Integer, Char -> Int) decimal = (10,octDecDigit) octal = (8,octDecDigit) hexadecimal = (16,hexDigit) -- readRational can understand negative rationals, exponents, everything. +tok_float, tok_primfloat, tok_primdouble :: String -> Token tok_float str = ITrational $! readRational str tok_primfloat str = ITprimfloat $! readRational str tok_primdouble str = ITprimdouble $! readRational str @@ -1068,21 +1059,31 @@ do_bol span _str _len = do return (L span ITvccurly) EQ -> do --trace "layout: inserting ';'" $ do - popLexState + _ <- popLexState return (L span ITsemi) GT -> do - popLexState + _ <- popLexState lexToken -- certain keywords put us in the "layout" state, where we might -- add an opening curly brace. -maybe_layout ITdo = pushLexState layout_do -maybe_layout ITmdo = pushLexState layout_do -maybe_layout ITof = pushLexState layout -maybe_layout ITlet = pushLexState layout -maybe_layout ITwhere = pushLexState layout -maybe_layout ITrec = pushLexState layout -maybe_layout _ = return () +maybe_layout :: Token -> P () +maybe_layout t = do -- If the alternative layout rule is enabled then + -- we never create an implicit layout context here. + -- Layout is handled XXX instead. + -- The code for closing implicit contexts, or + -- inserting implicit semi-colons, is therefore + -- irrelevant as it only applies in an implicit + -- context. + alr <- extension alternativeLayoutRule + unless alr $ f t + where f ITdo = pushLexState layout_do + f ITmdo = pushLexState layout_do + f ITof = pushLexState layout + f ITlet = pushLexState layout + f ITwhere = pushLexState layout + f ITrec = pushLexState layout + f _ = return () -- Pushing a new implicit layout context. If the indentation of the -- next token is not greater than the previous layout context, then @@ -1093,9 +1094,11 @@ maybe_layout _ = return () -- by a 'do', then we allow the new context to be at the same indentation as -- the previous context. This is what the 'strict' argument is for. -- +new_layout_context :: Bool -> Action new_layout_context strict span _buf _len = do - popLexState - (AI _ offset _) <- getInput + _ <- popLexState + (AI l _) <- getInput + let offset = srcLocCol l ctx <- getContext case ctx of Layout prev_off : _ | @@ -1109,8 +1112,9 @@ new_layout_context strict span _buf _len = do setContext (Layout offset : ctx) return (L span ITvocurly) +do_layout_left :: Action do_layout_left span _buf _len = do - popLexState + _ <- popLexState pushLexState bol -- we must be at the start of a line return (L span ITvccurly) @@ -1120,17 +1124,18 @@ do_layout_left span _buf _len = do setLine :: Int -> Action setLine code span buf len = do let line = parseUnsignedInteger buf len 10 octDecDigit - setSrcLoc (mkSrcLoc (srcSpanFile span) (fromIntegral line - 1) 0) + setSrcLoc (mkSrcLoc (srcSpanFile span) (fromIntegral line - 1) 1) -- subtract one: the line number refers to the *following* line - popLexState + _ <- popLexState pushLexState code lexToken setFile :: Int -> Action setFile code span buf len = do let file = lexemeToFastString (stepOn buf) (len-2) + setAlrLastLoc noSrcSpan setSrcLoc (mkSrcLoc file (srcSpanEndLine span) (srcSpanEndCol span)) - popLexState + _ <- popLexState pushLexState code lexToken @@ -1157,7 +1162,7 @@ lex_string_prag mkTok span _buf _len = case alexGetChar i of Just (c,i') | c == x -> isString i' xs _other -> False - err (AI end _ _) = failLocMsgP (srcSpanStart span) end "unterminated options pragma" + err (AI end _) = failLocMsgP (srcSpanStart span) end "unterminated options pragma" -- ----------------------------------------------------------------------------- @@ -1175,7 +1180,7 @@ lex_string :: String -> P Token lex_string s = do i <- getInput case alexGetChar' i of - Nothing -> lit_error + Nothing -> lit_error i Just ('"',i) -> do setInput i @@ -1200,51 +1205,57 @@ lex_string s = do Just ('\\',i) | Just ('&',i) <- next -> do setInput i; lex_string s - | Just (c,i) <- next, is_space c -> do + | Just (c,i) <- next, c <= '\x7f' && is_space c -> do + -- is_space only works for <= '\x7f' (#3751) setInput i; lex_stringgap s where next = alexGetChar' i - Just (c, i) -> do - c' <- lex_char c i - lex_string (c':s) + Just (c, i1) -> do + case c of + '\\' -> do setInput i1; c' <- lex_escape; lex_string (c':s) + c | isAny c -> do setInput i1; lex_string (c:s) + _other -> lit_error i +lex_stringgap :: String -> P Token lex_stringgap s = do - c <- getCharOrFail + i <- getInput + c <- getCharOrFail i case c of '\\' -> lex_string s c | is_space c -> lex_stringgap s - _other -> lit_error + _other -> lit_error i lex_char_tok :: Action -- Here we are basically parsing character literals, such as 'x' or '\n' -- but, when Template Haskell is on, we additionally spot -- 'x and ''T, returning ITvarQuote and ITtyQuote respectively, --- but WIHTOUT CONSUMING the x or T part (the parser does that). +-- but WITHOUT CONSUMING the x or T part (the parser does that). -- So we have to do two characters of lookahead: when we see 'x we need to -- see if there's a trailing quote lex_char_tok span _buf _len = do -- We've seen ' i1 <- getInput -- Look ahead to first character let loc = srcSpanStart span case alexGetChar' i1 of - Nothing -> lit_error + Nothing -> lit_error i1 - Just ('\'', i2@(AI end2 _ _)) -> do -- We've seen '' + Just ('\'', i2@(AI end2 _)) -> do -- We've seen '' th_exts <- extension thEnabled if th_exts then do setInput i2 return (L (mkSrcSpan loc end2) ITtyQuote) - else lit_error + else lit_error i1 - Just ('\\', i2@(AI _end2 _ _)) -> do -- We've seen 'backslash + Just ('\\', i2@(AI _end2 _)) -> do -- We've seen 'backslash setInput i2 lit_ch <- lex_escape - mc <- getCharOrFail -- Trailing quote + i3 <- getInput + mc <- getCharOrFail i3 -- Trailing quote if mc == '\'' then finish_char_tok loc lit_ch - else do setInput i2; lit_error + else lit_error i3 - Just (c, i2@(AI _end2 _ _)) - | not (isAny c) -> lit_error + Just (c, i2@(AI _end2 _)) + | not (isAny c) -> lit_error i1 | otherwise -> -- We've seen 'x, where x is a valid character @@ -1257,38 +1268,33 @@ lex_char_tok span _buf _len = do -- We've seen ' -- (including the possibility of EOF) -- If TH is on, just parse the quote only th_exts <- extension thEnabled - let (AI end _ _) = i1 + let (AI end _) = i1 if th_exts then return (L (mkSrcSpan loc end) ITvarQuote) - else do setInput i2; lit_error + else lit_error i2 finish_char_tok :: SrcLoc -> Char -> P (Located Token) finish_char_tok loc ch -- We've already seen the closing quote -- Just need to check for trailing # = do magicHash <- extension magicHashEnabled - i@(AI end _ _) <- getInput + i@(AI end _) <- getInput if magicHash then do case alexGetChar' i of - Just ('#',i@(AI end _ _)) -> do + Just ('#',i@(AI end _)) -> do setInput i return (L (mkSrcSpan loc end) (ITprimchar ch)) _other -> return (L (mkSrcSpan loc end) (ITchar ch)) - else do + else do return (L (mkSrcSpan loc end) (ITchar ch)) -lex_char :: Char -> AlexInput -> P Char -lex_char c inp = do - case c of - '\\' -> do setInput inp; lex_escape - c | isAny c -> do setInput inp; return c - _other -> lit_error - +isAny :: Char -> Bool isAny c | c > '\x7f' = isPrint c | otherwise = is_any c lex_escape :: P Char lex_escape = do - c <- getCharOrFail + i0 <- getInput + c <- getCharOrFail i0 case c of 'a' -> return '\a' 'b' -> return '\b' @@ -1300,10 +1306,11 @@ lex_escape = do '\\' -> return '\\' '"' -> return '\"' '\'' -> return '\'' - '^' -> do c <- getCharOrFail + '^' -> do i1 <- getInput + c <- getCharOrFail i1 if c >= '@' && c <= '_' then return (chr (ord c - ord '@')) - else lit_error + else lit_error i1 'x' -> readNum is_hexdigit 16 hexDigit 'o' -> readNum is_octdigit 8 octDecDigit @@ -1312,30 +1319,31 @@ lex_escape = do c1 -> do i <- getInput case alexGetChar' i of - Nothing -> lit_error + Nothing -> lit_error i0 Just (c2,i2) -> case alexGetChar' i2 of - Nothing -> do setInput i2; lit_error + Nothing -> do lit_error i0 Just (c3,i3) -> let str = [c1,c2,c3] in case [ (c,rest) | (p,c) <- silly_escape_chars, - Just rest <- [maybePrefixMatch p str] ] of + Just rest <- [stripPrefix p str] ] of (escape_char,[]):_ -> do setInput i3 return escape_char (escape_char,_:_):_ -> do setInput i2 return escape_char - [] -> lit_error + [] -> lit_error i0 readNum :: (Char -> Bool) -> Int -> (Char -> Int) -> P Char readNum is_digit base conv = do i <- getInput - c <- getCharOrFail + c <- getCharOrFail i if is_digit c then readNum2 is_digit base conv (conv c) - else do setInput i; lit_error + else lit_error i +readNum2 :: (Char -> Bool) -> Int -> (Char -> Int) -> Int -> P Char readNum2 is_digit base conv i = do input <- getInput read i input @@ -1346,8 +1354,9 @@ readNum2 is_digit base conv i = do _other -> do if i >= 0 && i <= 0x10FFFF then do setInput input; return (chr i) - else lit_error + else lit_error input +silly_escape_chars :: [(String, Char)] silly_escape_chars = [ ("NUL", '\NUL'), ("SOH", '\SOH'), @@ -1389,11 +1398,11 @@ silly_escape_chars = [ -- the position of the error in the buffer. This is so that we can report -- a correct location to the user, but also so we can detect UTF-8 decoding -- errors if they occur. -lit_error = lexError "lexical error in string/character literal" +lit_error :: AlexInput -> P a +lit_error i = do setInput i; lexError "lexical error in string/character literal" -getCharOrFail :: P Char -getCharOrFail = do - i <- getInput +getCharOrFail :: AlexInput -> P Char +getCharOrFail i = do case alexGetChar' i of Nothing -> lexError "unexpected end-of-file in string/character literal" Just (c,i) -> do setInput i; return c @@ -1403,8 +1412,9 @@ getCharOrFail = do lex_quasiquote_tok :: Action lex_quasiquote_tok span buf len = do - let quoter = reverse $ takeWhile (/= '$') - $ reverse $ lexemeToString buf (len - 1) + let quoter = tail (lexemeToString buf (len - 1)) + -- 'tail' drops the initial '[', + -- while the -1 drops the trailing '|' quoteStart <- getSrcLoc quote <- lex_quasiquote "" end <- getSrcLoc @@ -1417,7 +1427,7 @@ lex_quasiquote :: String -> P String lex_quasiquote s = do i <- getInput case alexGetChar' i of - Nothing -> lit_error + Nothing -> lit_error i Just ('\\',i) | Just ('|',i) <- next -> do @@ -1465,18 +1475,29 @@ data ParseResult a data PState = PState { buffer :: StringBuffer, - dflags :: DynFlags, - messages :: Messages, + dflags :: DynFlags, + messages :: Messages, last_loc :: SrcSpan, -- pos of previous token - last_offs :: !Int, -- offset of the previous token from the - -- beginning of the current line. - -- \t is equal to 8 spaces. last_len :: !Int, -- len of previous token - last_line_len :: !Int, loc :: SrcLoc, -- current loc (end of prev token + 1) extsBitmap :: !Int, -- bitmap that determines permitted extensions context :: [LayoutContext], - lex_state :: [Int] + lex_state :: [Int], + -- Used in the alternative layout rule: + -- These tokens are the next ones to be sent out. They are + -- just blindly emitted, without the rule looking at them again: + alr_pending_implicit_tokens :: [Located Token], + -- This is the next token to be considered or, if it is Nothing, + -- we need to get the next token from the input stream: + alr_next_token :: Maybe (Located Token), + -- This is what we consider to be the locatino of the last token + -- emitted: + alr_last_loc :: SrcSpan, + -- The stack of layout contexts: + alr_context :: [ALRContext], + -- Are we expecting a '{'? If it's Just, then the ALRLayout tells + -- us what sort of layout the '{' will open: + alr_expecting_ocurly :: Maybe ALRLayout } -- last_loc and last_len are used when generating error messages, -- and in pushCurrentContext only. Sigh, if only Happy passed the @@ -1484,6 +1505,13 @@ data PState = PState { -- Getting rid of last_loc would require finding another way to -- implement pushCurrentContext (which is only called from one place). +data ALRContext = ALRNoLayout Bool{- does it contain commas? -} + | ALRLayout ALRLayout Int +data ALRLayout = ALRLayoutLet + | ALRLayoutWhere + | ALRLayoutOf + | ALRLayoutDo + newtype P a = P { unP :: PState -> ParseResult a } instance Monad P where @@ -1512,6 +1540,17 @@ failLocMsgP loc1 loc2 str = P $ \_ -> PFailed (mkSrcSpan loc1 loc2) (text str) failSpanMsgP :: SrcSpan -> SDoc -> P a failSpanMsgP span msg = P $ \_ -> PFailed span msg +getPState :: P PState +getPState = P $ \s -> POk s s + +getDynFlags :: P DynFlags +getDynFlags = P $ \s -> POk s (dflags s) + +withThisPackage :: (PackageId -> a) -> P a +withThisPackage f + = do pkg <- liftM thisPackage getDynFlags + return $ f pkg + extension :: (Int -> Bool) -> P Bool extension p = P $ \s -> POk s (p $! extsBitmap s) @@ -1527,27 +1566,25 @@ setSrcLoc new_loc = P $ \s -> POk s{loc=new_loc} () getSrcLoc :: P SrcLoc getSrcLoc = P $ \s@(PState{ loc=loc }) -> POk s loc -setLastToken :: SrcSpan -> Int -> Int -> P () -setLastToken loc len line_len = P $ \s -> POk s { +setLastToken :: SrcSpan -> Int -> P () +setLastToken loc len = P $ \s -> POk s { last_loc=loc, - last_len=len, - last_line_len=line_len -} () + last_len=len + } () -data AlexInput = AI SrcLoc {-#UNPACK#-}!Int StringBuffer +data AlexInput = AI SrcLoc StringBuffer alexInputPrevChar :: AlexInput -> Char -alexInputPrevChar (AI _ _ buf) = prevChar buf '\n' +alexInputPrevChar (AI _ buf) = prevChar buf '\n' alexGetChar :: AlexInput -> Maybe (Char,AlexInput) -alexGetChar (AI loc ofs s) +alexGetChar (AI loc s) | atEnd s = Nothing - | otherwise = adj_c `seq` loc' `seq` ofs' `seq` s' `seq` + | otherwise = adj_c `seq` loc' `seq` s' `seq` --trace (show (ord c)) $ - Just (adj_c, (AI loc' ofs' s')) + Just (adj_c, (AI loc' s')) where (c,s') = nextChar s loc' = advanceSrcLoc loc c - ofs' = advanceOffs c ofs non_graphic = '\x0' upper = '\x1' @@ -1561,7 +1598,7 @@ alexGetChar (AI loc ofs s) | c <= '\x06' = non_graphic | c <= '\x7f' = c -- Alex doesn't handle Unicode, so when Unicode - -- character is encoutered we output these values + -- character is encountered we output these values -- with the actual character value hidden in the state. | otherwise = case generalCategory c of @@ -1593,25 +1630,19 @@ alexGetChar (AI loc ofs s) -- This version does not squash unicode characters, it is used when -- lexing strings. alexGetChar' :: AlexInput -> Maybe (Char,AlexInput) -alexGetChar' (AI loc ofs s) +alexGetChar' (AI loc s) | atEnd s = Nothing - | otherwise = c `seq` loc' `seq` ofs' `seq` s' `seq` + | otherwise = c `seq` loc' `seq` s' `seq` --trace (show (ord c)) $ - Just (c, (AI loc' ofs' s')) + Just (c, (AI loc' s')) where (c,s') = nextChar s loc' = advanceSrcLoc loc c - ofs' = advanceOffs c ofs - -advanceOffs :: Char -> Int -> Int -advanceOffs '\n' _ = 0 -advanceOffs '\t' offs = (offs `quot` 8 + 1) * 8 -advanceOffs _ offs = offs + 1 getInput :: P AlexInput -getInput = P $ \s@PState{ loc=l, last_offs=o, buffer=b } -> POk s (AI l o b) +getInput = P $ \s@PState{ loc=l, buffer=b } -> POk s (AI l b) setInput :: AlexInput -> P () -setInput (AI l o b) = P $ \s -> POk s{ loc=l, last_offs=o, buffer=b } () +setInput (AI l b) = P $ \s -> POk s{ loc=l, buffer=b } () pushLexState :: Int -> P () pushLexState ls = P $ \s@PState{ lex_state=l } -> POk s{lex_state=ls:l} () @@ -1622,58 +1653,136 @@ popLexState = P $ \s@PState{ lex_state=ls:l } -> POk s{ lex_state=l } ls getLexState :: P Int getLexState = P $ \s@PState{ lex_state=ls:_ } -> POk s ls +popNextToken :: P (Maybe (Located Token)) +popNextToken + = P $ \s@PState{ alr_next_token = m } -> + POk (s {alr_next_token = Nothing}) m + +setAlrLastLoc :: SrcSpan -> P () +setAlrLastLoc l = P $ \s -> POk (s {alr_last_loc = l}) () + +getAlrLastLoc :: P SrcSpan +getAlrLastLoc = P $ \s@(PState {alr_last_loc = l}) -> POk s l + +getALRContext :: P [ALRContext] +getALRContext = P $ \s@(PState {alr_context = cs}) -> POk s cs + +setALRContext :: [ALRContext] -> P () +setALRContext cs = P $ \s -> POk (s {alr_context = cs}) () + +setNextToken :: Located Token -> P () +setNextToken t = P $ \s -> POk (s {alr_next_token = Just t}) () + +popPendingImplicitToken :: P (Maybe (Located Token)) +popPendingImplicitToken + = P $ \s@PState{ alr_pending_implicit_tokens = ts } -> + case ts of + [] -> POk s Nothing + (t : ts') -> POk (s {alr_pending_implicit_tokens = ts'}) (Just t) + +setPendingImplicitTokens :: [Located Token] -> P () +setPendingImplicitTokens ts = P $ \s -> POk (s {alr_pending_implicit_tokens = ts}) () + +getAlrExpectingOCurly :: P (Maybe ALRLayout) +getAlrExpectingOCurly = P $ \s@(PState {alr_expecting_ocurly = b}) -> POk s b + +setAlrExpectingOCurly :: Maybe ALRLayout -> P () +setAlrExpectingOCurly b = P $ \s -> POk (s {alr_expecting_ocurly = b}) () + -- for reasons of efficiency, flags indicating language extensions (eg, -- -fglasgow-exts or -XParr) are represented by a bitmap stored in an unboxed -- integer -genericsBit, ffiBit, parrBit :: Int +genericsBit :: Int genericsBit = 0 -- {| and |} +ffiBit :: Int ffiBit = 1 +parrBit :: Int parrBit = 2 +arrowsBit :: Int arrowsBit = 4 +thBit :: Int thBit = 5 +ipBit :: Int ipBit = 6 +explicitForallBit :: Int explicitForallBit = 7 -- the 'forall' keyword and '.' symbol +bangPatBit :: Int bangPatBit = 8 -- Tells the parser to understand bang-patterns -- (doesn't affect the lexer) +tyFamBit :: Int tyFamBit = 9 -- indexed type families: 'family' keyword and kind sigs +haddockBit :: Int haddockBit = 10 -- Lex and parse Haddock comments +magicHashBit :: Int magicHashBit = 11 -- "#" in both functions and operators +kindSigsBit :: Int kindSigsBit = 12 -- Kind signatures on type variables +recursiveDoBit :: Int recursiveDoBit = 13 -- mdo +unicodeSyntaxBit :: Int unicodeSyntaxBit = 14 -- the forall symbol, arrow symbols, etc +unboxedTuplesBit :: Int unboxedTuplesBit = 15 -- (# and #) +standaloneDerivingBit :: Int standaloneDerivingBit = 16 -- standalone instance deriving declarations +transformComprehensionsBit :: Int transformComprehensionsBit = 17 +qqBit :: Int qqBit = 18 -- enable quasiquoting +inRulePragBit :: Int inRulePragBit = 19 +rawTokenStreamBit :: Int rawTokenStreamBit = 20 -- producing a token stream with all comments included +newQualOpsBit :: Int newQualOpsBit = 21 -- Haskell' qualified operator syntax, e.g. Prelude.(+) +recBit :: Int +recBit = 22 -- rec +alternativeLayoutRuleBit :: Int +alternativeLayoutRuleBit = 23 -genericsEnabled, ffiEnabled, parrEnabled :: Int -> Bool +always :: Int -> Bool always _ = True +genericsEnabled :: Int -> Bool genericsEnabled flags = testBit flags genericsBit -ffiEnabled flags = testBit flags ffiBit +parrEnabled :: Int -> Bool parrEnabled flags = testBit flags parrBit +arrowsEnabled :: Int -> Bool arrowsEnabled flags = testBit flags arrowsBit +thEnabled :: Int -> Bool thEnabled flags = testBit flags thBit +ipEnabled :: Int -> Bool ipEnabled flags = testBit flags ipBit +explicitForallEnabled :: Int -> Bool explicitForallEnabled flags = testBit flags explicitForallBit +bangPatEnabled :: Int -> Bool bangPatEnabled flags = testBit flags bangPatBit -tyFamEnabled flags = testBit flags tyFamBit +-- tyFamEnabled :: Int -> Bool +-- tyFamEnabled flags = testBit flags tyFamBit +haddockEnabled :: Int -> Bool haddockEnabled flags = testBit flags haddockBit +magicHashEnabled :: Int -> Bool magicHashEnabled flags = testBit flags magicHashBit -kindSigsEnabled flags = testBit flags kindSigsBit -recursiveDoEnabled flags = testBit flags recursiveDoBit +-- kindSigsEnabled :: Int -> Bool +-- kindSigsEnabled flags = testBit flags kindSigsBit +unicodeSyntaxEnabled :: Int -> Bool unicodeSyntaxEnabled flags = testBit flags unicodeSyntaxBit +unboxedTuplesEnabled :: Int -> Bool unboxedTuplesEnabled flags = testBit flags unboxedTuplesBit +standaloneDerivingEnabled :: Int -> Bool standaloneDerivingEnabled flags = testBit flags standaloneDerivingBit -transformComprehensionsEnabled flags = testBit flags transformComprehensionsBit +qqEnabled :: Int -> Bool qqEnabled flags = testBit flags qqBit -inRulePrag flags = testBit flags inRulePragBit +-- inRulePrag :: Int -> Bool +-- inRulePrag flags = testBit flags inRulePragBit +rawTokenStreamEnabled :: Int -> Bool rawTokenStreamEnabled flags = testBit flags rawTokenStreamBit +newQualOps :: Int -> Bool newQualOps flags = testBit flags newQualOpsBit +oldQualOps :: Int -> Bool oldQualOps flags = not (newQualOps flags) +alternativeLayoutRule :: Int -> Bool +alternativeLayoutRule flags = testBit flags alternativeLayoutRuleBit -- PState for parsing options pragmas -- @@ -1684,13 +1793,16 @@ pragState dynflags buf loc = messages = emptyMessages, dflags = dynflags, last_loc = mkSrcSpan loc loc, - last_offs = 0, last_len = 0, - last_line_len = 0, loc = loc, extsBitmap = 0, context = [], - lex_state = [bol, option_prags, 0] + lex_state = [bol, option_prags, 0], + alr_pending_implicit_tokens = [], + alr_next_token = Nothing, + alr_last_loc = noSrcSpan, + alr_context = [], + alr_expecting_ocurly = Nothing } @@ -1703,41 +1815,42 @@ mkPState buf loc flags = dflags = flags, messages = emptyMessages, last_loc = mkSrcSpan loc loc, - last_offs = 0, last_len = 0, - last_line_len = 0, loc = loc, extsBitmap = fromIntegral bitmap, context = [], - lex_state = [bol, 0] + lex_state = [bol, 0], -- we begin in the layout state if toplev_layout is set + alr_pending_implicit_tokens = [], + alr_next_token = Nothing, + alr_last_loc = noSrcSpan, + alr_context = [], + alr_expecting_ocurly = Nothing } where bitmap = genericsBit `setBitIf` dopt Opt_Generics flags - .|. ffiBit `setBitIf` dopt Opt_ForeignFunctionInterface flags - .|. parrBit `setBitIf` dopt Opt_PArr flags - .|. arrowsBit `setBitIf` dopt Opt_Arrows flags - .|. thBit `setBitIf` dopt Opt_TemplateHaskell flags - .|. qqBit `setBitIf` dopt Opt_QuasiQuotes flags - .|. ipBit `setBitIf` dopt Opt_ImplicitParams flags - .|. explicitForallBit `setBitIf` dopt Opt_ScopedTypeVariables flags - .|. explicitForallBit `setBitIf` dopt Opt_LiberalTypeSynonyms flags - .|. explicitForallBit `setBitIf` dopt Opt_PolymorphicComponents flags - .|. explicitForallBit `setBitIf` dopt Opt_ExistentialQuantification flags - .|. explicitForallBit `setBitIf` dopt Opt_Rank2Types flags - .|. explicitForallBit `setBitIf` dopt Opt_RankNTypes flags - .|. bangPatBit `setBitIf` dopt Opt_BangPatterns flags - .|. tyFamBit `setBitIf` dopt Opt_TypeFamilies flags - .|. haddockBit `setBitIf` dopt Opt_Haddock flags - .|. magicHashBit `setBitIf` dopt Opt_MagicHash flags - .|. kindSigsBit `setBitIf` dopt Opt_KindSignatures flags - .|. recursiveDoBit `setBitIf` dopt Opt_RecursiveDo flags - .|. unicodeSyntaxBit `setBitIf` dopt Opt_UnicodeSyntax flags - .|. unboxedTuplesBit `setBitIf` dopt Opt_UnboxedTuples flags + .|. ffiBit `setBitIf` dopt Opt_ForeignFunctionInterface flags + .|. parrBit `setBitIf` dopt Opt_PArr flags + .|. arrowsBit `setBitIf` dopt Opt_Arrows flags + .|. thBit `setBitIf` dopt Opt_TemplateHaskell flags + .|. qqBit `setBitIf` dopt Opt_QuasiQuotes flags + .|. ipBit `setBitIf` dopt Opt_ImplicitParams flags + .|. explicitForallBit `setBitIf` dopt Opt_ExplicitForAll flags + .|. bangPatBit `setBitIf` dopt Opt_BangPatterns flags + .|. tyFamBit `setBitIf` dopt Opt_TypeFamilies flags + .|. haddockBit `setBitIf` dopt Opt_Haddock flags + .|. magicHashBit `setBitIf` dopt Opt_MagicHash flags + .|. kindSigsBit `setBitIf` dopt Opt_KindSignatures flags + .|. recursiveDoBit `setBitIf` dopt Opt_RecursiveDo flags + .|. recBit `setBitIf` dopt Opt_DoRec flags + .|. recBit `setBitIf` dopt Opt_Arrows flags + .|. unicodeSyntaxBit `setBitIf` dopt Opt_UnicodeSyntax flags + .|. unboxedTuplesBit `setBitIf` dopt Opt_UnboxedTuples flags .|. standaloneDerivingBit `setBitIf` dopt Opt_StandaloneDeriving flags .|. transformComprehensionsBit `setBitIf` dopt Opt_TransformListComp flags .|. rawTokenStreamBit `setBitIf` dopt Opt_KeepRawTokenStream flags .|. newQualOpsBit `setBitIf` dopt Opt_NewQualifiedOperators flags + .|. alternativeLayoutRuleBit `setBitIf` dopt Opt_AlternativeLayoutRule flags -- setBitIf :: Int -> Bool -> Int b `setBitIf` cond | cond = bit b @@ -1770,14 +1883,15 @@ popContext = P $ \ s@(PState{ buffer = buf, context = ctx, -- This is only used at the outer level of a module when the 'module' -- keyword is missing. pushCurrentContext :: P () -pushCurrentContext = P $ \ s@PState{ last_offs=offs, last_line_len=len, context=ctx } -> - POk s{context = Layout (offs-len) : ctx} () ---trace ("off: " ++ show offs ++ ", len: " ++ show len) $ POk s{context = Layout (offs-len) : ctx} () +pushCurrentContext = P $ \ s@PState{ last_loc=loc, context=ctx } -> + POk s{context = Layout (srcSpanStartCol loc) : ctx} () getOffside :: P Ordering -getOffside = P $ \s@PState{last_offs=offs, context=stk} -> +getOffside = P $ \s@PState{last_loc=loc, context=stk} -> + let offs = srcSpanStartCol loc in let ord = case stk of - (Layout n:_) -> compare offs n + (Layout n:_) -> --trace ("layout: " ++ show n ++ ", offs: " ++ show offs) $ + compare offs n _ -> GT in POk s ord @@ -1809,7 +1923,7 @@ srcParseFail = P $ \PState{ buffer = buf, last_len = len, lexError :: String -> P a lexError str = do loc <- getSrcLoc - (AI end _ buf) <- getInput + (AI end buf) <- getInput reportLexError loc end buf str -- ----------------------------------------------------------------------------- @@ -1818,32 +1932,205 @@ lexError str = do lexer :: (Located Token -> P a) -> P a lexer cont = do - tok@(L _span _tok__) <- lexToken --- trace ("token: " ++ show tok__) $ do + alr <- extension alternativeLayoutRule + let lexTokenFun = if alr then lexTokenAlr else lexToken + tok@(L _span _tok__) <- lexTokenFun + --trace ("token: " ++ show _tok__) $ do cont tok +lexTokenAlr :: P (Located Token) +lexTokenAlr = do mPending <- popPendingImplicitToken + t <- case mPending of + Nothing -> + do mNext <- popNextToken + t <- case mNext of + Nothing -> lexToken + Just next -> return next + alternativeLayoutRuleToken t + Just t -> + return t + setAlrLastLoc (getLoc t) + case unLoc t of + ITwhere -> setAlrExpectingOCurly (Just ALRLayoutWhere) + ITlet -> setAlrExpectingOCurly (Just ALRLayoutLet) + ITof -> setAlrExpectingOCurly (Just ALRLayoutOf) + ITdo -> setAlrExpectingOCurly (Just ALRLayoutDo) + ITmdo -> setAlrExpectingOCurly (Just ALRLayoutDo) + ITrec -> setAlrExpectingOCurly (Just ALRLayoutDo) + _ -> return () + return t + +alternativeLayoutRuleToken :: Located Token -> P (Located Token) +alternativeLayoutRuleToken t + = do context <- getALRContext + lastLoc <- getAlrLastLoc + mExpectingOCurly <- getAlrExpectingOCurly + let thisLoc = getLoc t + thisCol = srcSpanStartCol thisLoc + newLine = (lastLoc == noSrcSpan) + || (srcSpanStartLine thisLoc > srcSpanEndLine lastLoc) + case (unLoc t, context, mExpectingOCurly) of + -- This case handles a GHC extension to the original H98 + -- layout rule... + (ITocurly, _, Just _) -> + do setAlrExpectingOCurly Nothing + setALRContext (ALRNoLayout (containsCommas ITocurly) : context) + return t + -- ...and makes this case unnecessary + {- + -- I think our implicit open-curly handling is slightly + -- different to John's, in how it interacts with newlines + -- and "in" + (ITocurly, _, Just _) -> + do setAlrExpectingOCurly Nothing + setNextToken t + lexTokenAlr + -} + (_, ALRLayout _ col : ls, Just expectingOCurly) + | (thisCol > col) || + (thisCol == col && + isNonDecreasingIntentation expectingOCurly) -> + do setAlrExpectingOCurly Nothing + setALRContext (ALRLayout expectingOCurly thisCol : context) + setNextToken t + return (L thisLoc ITocurly) + | otherwise -> + do setAlrExpectingOCurly Nothing + setPendingImplicitTokens [L lastLoc ITccurly] + setNextToken t + return (L lastLoc ITocurly) + (_, _, Just expectingOCurly) -> + do setAlrExpectingOCurly Nothing + setALRContext (ALRLayout expectingOCurly thisCol : context) + setNextToken t + return (L thisLoc ITocurly) + -- We do the [] cases earlier than in the spec, as we + -- have an actual EOF token + (ITeof, ALRLayout _ _ : ls, _) -> + do setALRContext ls + setNextToken t + return (L thisLoc ITccurly) + (ITeof, _, _) -> + return t + -- the other ITeof case omitted; general case below covers it + (ITin, ALRLayout ALRLayoutLet _ : ls, _) + | newLine -> + do setPendingImplicitTokens [t] + setALRContext ls + return (L thisLoc ITccurly) + (_, ALRLayout _ col : ls, _) + | newLine && thisCol == col -> + do setNextToken t + return (L thisLoc ITsemi) + | newLine && thisCol < col -> + do setALRContext ls + setNextToken t + -- Note that we use lastLoc, as we may need to close + -- more layouts, or give a semicolon + return (L lastLoc ITccurly) + (u, _, _) + | isALRopen u -> + do setALRContext (ALRNoLayout (containsCommas u) : context) + return t + (u, _, _) + | isALRclose u -> + case context of + ALRLayout _ _ : ls -> + do setALRContext ls + setNextToken t + return (L thisLoc ITccurly) + ALRNoLayout _ : ls -> + do setALRContext ls + return t + [] -> + -- XXX This is an error in John's code, but + -- it looks reachable to me at first glance + return t + (ITin, ALRLayout ALRLayoutLet _ : ls, _) -> + do setALRContext ls + setPendingImplicitTokens [t] + return (L thisLoc ITccurly) + (ITin, ALRLayout _ _ : ls, _) -> + do setALRContext ls + setNextToken t + return (L thisLoc ITccurly) + -- the other ITin case omitted; general case below covers it + (ITcomma, ALRLayout _ _ : ls, _) + | topNoLayoutContainsCommas ls -> + do setALRContext ls + setNextToken t + return (L thisLoc ITccurly) + (ITwhere, ALRLayout ALRLayoutDo _ : ls, _) -> + do setALRContext ls + setPendingImplicitTokens [t] + return (L thisLoc ITccurly) + -- the other ITwhere case omitted; general case below covers it + (_, _, _) -> return t + +isALRopen :: Token -> Bool +isALRopen ITcase = True +isALRopen ITif = True +isALRopen IToparen = True +isALRopen ITobrack = True +isALRopen ITocurly = True +-- GHC Extensions: +isALRopen IToubxparen = True +isALRopen ITparenEscape = True +isALRopen _ = False + +isALRclose :: Token -> Bool +isALRclose ITof = True +isALRclose ITthen = True +isALRclose ITcparen = True +isALRclose ITcbrack = True +isALRclose ITccurly = True +-- GHC Extensions: +isALRclose ITcubxparen = True +isALRclose _ = False + +isNonDecreasingIntentation :: ALRLayout -> Bool +isNonDecreasingIntentation ALRLayoutDo = True +isNonDecreasingIntentation _ = False + +containsCommas :: Token -> Bool +containsCommas IToparen = True +containsCommas ITobrack = True +-- John doesn't have {} as containing commas, but records contain them, +-- which caused a problem parsing Cabal's Distribution.Simple.InstallDirs +-- (defaultInstallDirs). +containsCommas ITocurly = True +-- GHC Extensions: +containsCommas IToubxparen = True +containsCommas _ = False + +topNoLayoutContainsCommas :: [ALRContext] -> Bool +topNoLayoutContainsCommas [] = False +topNoLayoutContainsCommas (ALRLayout _ _ : ls) = topNoLayoutContainsCommas ls +topNoLayoutContainsCommas (ALRNoLayout b : _) = b + lexToken :: P (Located Token) lexToken = do - inp@(AI loc1 _ buf) <- getInput + inp@(AI loc1 buf) <- getInput sc <- getLexState exts <- getExts case alexScanUser exts inp sc of AlexEOF -> do let span = mkSrcSpan loc1 loc1 - setLastToken span 0 0 + setLastToken span 0 return (L span ITeof) - AlexError (AI loc2 _ buf) -> + AlexError (AI loc2 buf) -> reportLexError loc1 loc2 buf "lexical error" AlexSkip inp2 _ -> do setInput inp2 lexToken - AlexToken inp2@(AI end _ buf2) _ t -> do + AlexToken inp2@(AI end buf2) _ t -> do setInput inp2 let span = mkSrcSpan loc1 end let bytes = byteDiff buf buf2 - span `seq` setLastToken span bytes bytes + span `seq` setLastToken span bytes t span buf bytes +reportLexError :: SrcLoc -> SrcLoc -> StringBuffer -> [Char] -> P a reportLexError loc1 loc2 buf str | atEnd buf = failLocMsgP loc1 loc2 (str ++ " at end of input") | otherwise = @@ -1862,4 +2149,59 @@ lexTokenStream buf loc dflags = unP go initState case ltok of L _ ITeof -> return [] _ -> liftM (ltok:) go + +linePrags = Map.singleton "line" (begin line_prag2) + +fileHeaderPrags = Map.fromList([("options", lex_string_prag IToptions_prag), + ("options_ghc", lex_string_prag IToptions_prag), + ("options_haddock", lex_string_prag ITdocOptions), + ("language", token ITlanguage_prag), + ("include", lex_string_prag ITinclude_prag)]) + +ignoredPrags = Map.fromList (map ignored pragmas) + where ignored opt = (opt, nested_comment lexToken) + impls = ["hugs", "nhc98", "jhc", "yhc", "catch", "derive"] + options_pragmas = map ("options_" ++) impls + -- CFILES is a hugs-only thing. + pragmas = options_pragmas ++ ["cfiles", "contract"] + +oneWordPrags = Map.fromList([("rules", rulePrag), + ("inline", token (ITinline_prag True)), + ("notinline", token (ITinline_prag False)), + ("specialize", token ITspec_prag), + ("source", token ITsource_prag), + ("warning", token ITwarning_prag), + ("deprecated", token ITdeprecated_prag), + ("scc", token ITscc_prag), + ("generated", token ITgenerated_prag), + ("core", token ITcore_prag), + ("unpack", token ITunpack_prag), + ("ann", token ITann_prag)]) + +twoWordPrags = Map.fromList([("inline conlike", token (ITinline_conlike_prag True)), + ("notinline conlike", token (ITinline_conlike_prag False)), + ("specialize inline", token (ITspec_inline_prag True)), + ("specialize notinline", token (ITspec_inline_prag False))]) + + +dispatch_pragmas :: Map String Action -> Action +dispatch_pragmas prags span buf len = case Map.lookup (clean_pragma (lexemeToString buf len)) prags of + Just found -> found span buf len + Nothing -> lexError "unknown pragma" + +known_pragma :: Map String Action -> AlexAccPred Int +known_pragma prags _ _ len (AI _ buf) = (isJust $ Map.lookup (clean_pragma (lexemeToString (offsetBytes (- len) buf) len)) prags) + && (nextCharIs buf (\c -> not (isAlphaNum c || c == '_'))) + +clean_pragma :: String -> String +clean_pragma prag = canon_ws (map toLower (unprefix prag)) + where unprefix prag' = case stripPrefix "{-#" prag' of + Just rest -> rest + Nothing -> prag' + canonical prag' = case prag' of + "noinline" -> "notinline" + "specialise" -> "specialize" + "constructorlike" -> "conlike" + _ -> prag' + canon_ws s = unwords (map canonical (words s)) }