{
module Lexer (
- Token(..), Token__(..), lexer, mkPState, showPFailed,
- P(..), ParseResult(..), setSrcLocFor, getSrcLoc,
- failMsgP, failLocMsgP, srcParseFail,
+ Token(..), lexer, mkPState,
+ P(..), ParseResult(..), getSrcLoc,
+ failMsgP, failLocMsgP, failSpanMsgP, srcParseFail,
popContext, pushCurrentContext,
) where
#include "HsVersions.h"
-import ForeignCall ( Safety(..) )
import ErrUtils ( Message )
import Outputable
import StringBuffer
import DATA_BITS
import Char
import Ratio
-import TRACE
+--import TRACE
}
-$whitechar = [\ \t\n\r\f\v]
+$whitechar = [\ \t\n\r\f\v\xa0]
$white_no_nl = $whitechar # \n
$ascdigit = 0-9
-- {-# LINE <line> "<file>" #-}
<line_prag2> $digit+ { set_line line_prag2a }
<line_prag2a> \" [$graphic \ ]* \" { set_file line_prag2b }
-<line_prag2b> "#-}" { pop }
+<line_prag2b> "#-}"|"-}" { pop }
+ -- NOTE: accept -} at the end of a LINE pragma, for compatibility
+ -- with older versions of GHC which generated these.
<0,glaexts> {
"{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e)
{ token ITdeprecated_prag }
"{-#" $whitechar* (SCC|scc) { token ITscc_prag }
"{-#" $whitechar* (CORE|core) { token ITcore_prag }
+ "{-#" $whitechar* (UNPACK|unpack) { token ITunpack_prag }
"{-#" { nested_comment }
}
<0,glaexts> {
- "(|" / { ifExtension arrowsEnabled } { special IToparenbar }
+ "(|" / { ifExtension arrowsEnabled `alexAndPred` notFollowedBySymbol }
+ { special IToparenbar }
"|)" / { ifExtension arrowsEnabled } { special ITcparenbar }
}
}
<glaexts> {
- "(#" { token IToubxparen }
+ "(#" / { notFollowedBySymbol } { token IToubxparen }
"#)" { token ITcubxparen }
"{|" { token ITocurlybar }
"|}" { token ITccurlybar }
-- -----------------------------------------------------------------------------
-- The token type
-data Token = T SrcLoc{-start-} SrcLoc{-end-} Token__
-
-data Token__
+data Token
= ITas -- Haskell keywords
| ITcase
| ITclass
| ITline_prag
| ITscc_prag
| ITcore_prag -- hdaume: core annotations
+ | ITunpack_prag
| ITclose_prag
| ITdotdot -- reserved symbols
| ITcloseQuote -- |]
| ITidEscape FastString -- $x
| ITparenEscape -- $(
- | ITreifyType
- | ITreifyDecl
- | ITreifyFixity
+ | ITvarQuote -- '
+ | ITtyQuote -- ''
-- Arrow notation extension
| ITproc
deriving Show -- debugging
#endif
-isSpecial :: Token__ -> Bool
+isSpecial :: Token -> Bool
-- If we see M.x, where x is a keyword, but
-- is special, we treat is as just plain M.x,
-- not as a keyword.
( "forall", ITforall, bit glaExtsBit),
( "mdo", ITmdo, bit glaExtsBit),
- ( "reifyDecl", ITreifyDecl, bit thBit),
- ( "reifyType", ITreifyType, bit thBit),
- ( "reifyFixity",ITreifyFixity, bit thBit),
( "foreign", ITforeign, bit ffiBit),
( "export", ITexport, bit ffiBit),
-- -----------------------------------------------------------------------------
-- Lexer actions
-type Action = SrcLoc -> SrcLoc -> StringBuffer -> Int -> P Token
+type Action = SrcSpan -> StringBuffer -> Int -> P (Located Token)
-special :: Token__ -> Action
-special tok loc end _buf len = return (T loc end tok)
+special :: Token -> Action
+special tok span _buf len = return (L span tok)
-token, layout_token :: Token__ -> Action
-token t loc end buf len = return (T loc end t)
-layout_token t loc end buf len = pushLexState layout >> return (T loc end t)
+token, layout_token :: Token -> Action
+token t span buf len = return (L span t)
+layout_token t span buf len = pushLexState layout >> return (L span t)
-idtoken :: (StringBuffer -> Int -> Token__) -> Action
-idtoken f loc end buf len = return (T loc end $! (f buf len))
+idtoken :: (StringBuffer -> Int -> Token) -> Action
+idtoken f span buf len = return (L span $! (f buf len))
-skip_one_varid :: (FastString -> Token__) -> Action
-skip_one_varid f loc end buf len
- = return (T loc end $! f (lexemeToFastString (stepOn buf) (len-1)))
+skip_one_varid :: (FastString -> Token) -> Action
+skip_one_varid f span buf len
+ = return (L span $! f (lexemeToFastString (stepOn buf) (len-1)))
-strtoken :: (String -> Token__) -> Action
-strtoken f loc end buf len =
- return (T loc end $! (f $! lexemeToString buf len))
+strtoken :: (String -> Token) -> Action
+strtoken f span buf len =
+ return (L span $! (f $! lexemeToString buf len))
-init_strtoken :: Int -> (String -> Token__) -> Action
+init_strtoken :: Int -> (String -> Token) -> Action
-- like strtoken, but drops the last N character(s)
-init_strtoken drop f loc end buf len =
- return (T loc end $! (f $! lexemeToString buf (len-drop)))
+init_strtoken drop f span buf len =
+ return (L span $! (f $! lexemeToString buf (len-drop)))
begin :: Int -> Action
-begin code _loc _end _str _len = do pushLexState code; lexToken
+begin code _span _str _len = do pushLexState code; lexToken
pop :: Action
-pop _loc _end _buf _len = do popLexState; lexToken
+pop _span _buf _len = do popLexState; lexToken
pop_and :: Action -> Action
-pop_and act loc end buf len = do popLexState; act loc end buf len
+pop_and act span buf len = do popLexState; act span buf len
notFollowedBy char _ _ _ (_,buf) = atEnd buf || currentChar buf /= char
+notFollowedBySymbol _ _ _ (_,buf)
+ = atEnd buf || currentChar buf `notElem` "!#$%&*+./<=>?@\\^|-~"
+
ifExtension pred bits _ _ _ = pred bits
{-
using regular expressions.
-}
nested_comment :: Action
-nested_comment loc _end _str _len = do
+nested_comment span _str _len = do
input <- getInput
go 1 input
where go 0 input = do setInput input; lexToken
Just (c,input) -> go n input
c -> go n input
- err input = do failLocMsgP loc (fst input) "unterminated `{-'"
+ err input = do failLocMsgP (srcSpanStart span) (fst input)
+ "unterminated `{-'"
open_brace, close_brace :: Action
-open_brace loc end _str _len = do
+open_brace span _str _len = do
ctx <- getContext
setContext (NoLayout:ctx)
- return (T loc end ITocurly)
-close_brace loc end _str _len = do
+ return (L span ITocurly)
+close_brace span _str _len = do
popContext
- return (T loc end ITccurly)
+ return (L span ITccurly)
-- We have to be careful not to count M.<varid> as a qualified name
-- when <varid> is a keyword. We hack around this by catching
-- the offending tokens afterward, and re-lexing in a different state.
-check_qvarid loc end buf len = do
+check_qvarid span buf len = do
case lookupUFM reservedWordsFM var of
Just (keyword,exts)
| not (isSpecial keyword) ->
_other -> return token
where
(mod,var) = splitQualName buf len
- token = T loc end (ITqvarid (mod,var))
+ token = L span (ITqvarid (mod,var))
try_again = do
- setInput (loc,buf)
+ setInput (srcSpanStart span,buf)
pushLexState bad_qvarid
lexToken
(lexemeToFastString orig_buf dot_off,
lexemeToFastString (stepOnBy (dot_off+1) orig_buf) (len - dot_off -1))
-varid loc end buf len =
+varid span buf len =
case lookupUFM reservedWordsFM fs of
Just (keyword,0) -> do
maybe_layout keyword
- return (T loc end keyword)
+ return (L span keyword)
Just (keyword,exts) -> do
b <- extension (\i -> exts .&. i /= 0)
if b then do maybe_layout keyword
- return (T loc end keyword)
- else return (T loc end (ITvarid fs))
- _other -> return (T loc end (ITvarid fs))
+ return (L span keyword)
+ else return (L span (ITvarid fs))
+ _other -> return (L span (ITvarid fs))
where
fs = lexemeToFastString buf len
varsym = sym ITvarsym
consym = sym ITconsym
-sym con loc end buf len =
+sym con span buf len =
case lookupUFM reservedSymsFM fs of
- Just (keyword,0) -> return (T loc end keyword)
+ Just (keyword,0) -> return (L span keyword)
Just (keyword,exts) -> do
b <- extension (\i -> exts .&. i /= 0)
- if b then return (T loc end keyword)
- else return (T loc end $! con fs)
- _other -> return (T loc end $! con fs)
+ if b then return (L span keyword)
+ else return (L span $! con fs)
+ _other -> return (L span $! con fs)
where
fs = lexemeToFastString buf len
-tok_decimal loc end buf len
- = return (T loc end (ITinteger $! parseInteger buf len 10 oct_or_dec))
+tok_decimal span buf len
+ = return (L span (ITinteger $! parseInteger buf len 10 oct_or_dec))
-tok_octal loc end buf len
- = return (T loc end (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 8 oct_or_dec))
+tok_octal span buf len
+ = return (L span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 8 oct_or_dec))
-tok_hexadecimal loc end buf len
- = return (T loc end (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 16 hex))
+tok_hexadecimal span buf len
+ = return (L span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 16 hex))
-prim_decimal loc end buf len
- = return (T loc end (ITprimint $! parseInteger buf (len-1) 10 oct_or_dec))
+prim_decimal span buf len
+ = return (L span (ITprimint $! parseInteger buf (len-1) 10 oct_or_dec))
-prim_octal loc end buf len
- = return (T loc end (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 8 oct_or_dec))
+prim_octal span buf len
+ = return (L span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 8 oct_or_dec))
-prim_hexadecimal loc end buf len
- = return (T loc end (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 16 hex))
+prim_hexadecimal span buf len
+ = return (L span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 16 hex))
tok_float str = ITrational $! readRational__ str
prim_float str = ITprimfloat $! readRational__ str
-- we're at the first token on a line, insert layout tokens if necessary
do_bol :: Action
-do_bol loc end _str _len = do
- pos <- getOffside end
+do_bol span _str _len = do
+ pos <- getOffside (srcSpanEnd span)
case pos of
LT -> do
--trace "layout: inserting '}'" $ do
popContext
-- do NOT pop the lex state, we might have a ';' to insert
- return (T loc end ITvccurly)
+ return (L span ITvccurly)
EQ -> do
--trace "layout: inserting ';'" $ do
popLexState
- return (T loc end ITsemi)
+ return (L span ITsemi)
GT -> do
popLexState
lexToken
-- 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 strict loc end _buf _len = do
+new_layout_context strict span _buf _len = do
popLexState
- let offset = srcLocCol loc
+ let offset = srcSpanStartCol span
ctx <- getContext
case ctx of
Layout prev_off : _ |
-- token is indented to the left of the previous context.
-- we must generate a {} sequence now.
pushLexState layout_left
- return (T loc end ITvocurly)
+ return (L span ITvocurly)
other -> do
setContext (Layout offset : ctx)
- return (T loc end ITvocurly)
+ return (L span ITvocurly)
-do_layout_left loc end _buf _len = do
+do_layout_left span _buf _len = do
popLexState
pushLexState bol -- we must be at the start of a line
- return (T loc end ITvccurly)
+ return (L span ITvccurly)
-- -----------------------------------------------------------------------------
-- LINE pragmas
set_line :: Int -> Action
-set_line code loc end buf len = do
+set_line code span buf len = do
let line = parseInteger buf len 10 oct_or_dec
- setSrcLoc (mkSrcLoc (srcLocFile end) (fromIntegral line - 1) 0)
+ setSrcLoc (mkSrcLoc (srcSpanFile span) (fromIntegral line - 1) 0)
-- subtract one: the line number refers to the *following* line
popLexState
pushLexState code
lexToken
set_file :: Int -> Action
-set_file code loc end buf len = do
+set_file code span buf len = do
let file = lexemeToFastString (stepOn buf) (len-2)
- setSrcLoc (mkSrcLoc file (srcLocLine end) (srcLocCol end))
+ setSrcLoc (mkSrcLoc file (srcSpanEndLine span) (srcSpanEndCol span))
popLexState
pushLexState code
lexToken
-- This stuff is horrible. I hates it.
lex_string_tok :: Action
-lex_string_tok loc end buf len = do
+lex_string_tok span buf len = do
tok <- lex_string ""
end <- getSrcLoc
- return (T loc end tok)
+ return (L (mkSrcSpan (srcSpanStart span) end) tok)
-lex_string :: String -> P Token__
+lex_string :: String -> P Token
lex_string s = do
i <- getInput
case alexGetChar i of
c <- lex_char
lex_string (c:s)
-
lex_stringgap s = do
c <- getCharOrFail
case c of
lex_char_tok :: Action
-lex_char_tok loc _end buf len = do
- c <- lex_char
- mc <- getCharOrFail
- case mc of
- '\'' -> do
- glaexts <- extension glaExtsEnabled
- if glaexts
- then do
- i@(end,_) <- getInput
- case alexGetChar i of
+-- 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).
+-- 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
+
+ Just ('\'', i2@(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
+
+ Just ('\\', i2@(end2,_)) -> do -- We've seen 'backslash
+ setInput i2
+ lit_ch <- lex_escape
+ mc <- getCharOrFail -- Trailing quote
+ if mc == '\'' then finish_char_tok loc lit_ch
+ else lit_error
+
+ Just (c, i2@(end2,_)) | not (is_any c) -> lit_error
+ | otherwise ->
+
+ -- We've seen 'x, where x is a valid character
+ -- (i.e. not newline etc) but not a quote or backslash
+ case alexGetChar i2 of -- Look ahead one more character
+ Nothing -> lit_error
+ Just ('\'', i3) -> do -- We've seen 'x'
+ setInput i3
+ finish_char_tok loc c
+ _other -> do -- We've seen 'x not followed by quote
+ -- If TH is on, just parse the quote only
+ th_exts <- extension thEnabled
+ if th_exts then return (L (mkSrcSpan loc (fst i1)) ITvarQuote)
+ else lit_error
+
+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 glaexts <- extension glaExtsEnabled
+ i@(end,_) <- getInput
+ if glaexts then do
+ case alexGetChar i of
Just ('#',i@(end,_)) -> do
setInput i
- return (T loc end (ITprimchar c))
+ return (L (mkSrcSpan loc end) (ITprimchar ch))
_other ->
- return (T loc end (ITchar c))
+ return (L (mkSrcSpan loc end) (ITchar ch))
else do
- end <- getSrcLoc
- return (T loc end (ITchar c))
-
- _other -> lit_error
+ return (L (mkSrcSpan loc end) (ITchar ch))
lex_char :: P Char
lex_char = do
data ParseResult a
= POk PState a
| PFailed
- SrcLoc SrcLoc -- The start and end of the text span related to
+ SrcSpan -- The start and end of the text span related to
-- the error. Might be used in environments which can
-- show this span, e.g. by highlighting it.
Message -- The error message
-showPFailed loc1 loc2 err = hcat [ppr loc1, text ": ", err]
-
data PState = PState {
buffer :: StringBuffer,
- last_loc :: SrcLoc, -- pos of previous token
- last_len :: !Int, -- len of previous token
+ last_loc :: SrcSpan, -- pos of previous token
+ last_len :: !Int, -- len of previous token
loc :: SrcLoc, -- current loc (end of prev token + 1)
extsBitmap :: !Int, -- bitmap that determines permitted extensions
context :: [LayoutContext],
thenP :: P a -> (a -> P b) -> P b
(P m) `thenP` k = P $ \ s ->
case m s of
- POk s1 a -> (unP (k a)) s1
- PFailed l1 l2 err -> PFailed l1 l2 err
+ POk s1 a -> (unP (k a)) s1
+ PFailed span err -> PFailed span err
failP :: String -> P a
-failP msg = P $ \s -> PFailed (last_loc s) (loc s) (text msg)
+failP msg = P $ \s -> PFailed (last_loc s) (text msg)
failMsgP :: String -> P a
-failMsgP msg = P $ \s -> PFailed (last_loc s) (loc s) (text msg)
+failMsgP msg = P $ \s -> PFailed (last_loc s) (text msg)
failLocMsgP :: SrcLoc -> SrcLoc -> String -> P a
-failLocMsgP loc1 loc2 str = P $ \s -> PFailed loc1 loc2 (text str)
+failLocMsgP loc1 loc2 str = P $ \s -> PFailed (mkSrcSpan loc1 loc2) (text str)
+
+failSpanMsgP :: SrcSpan -> String -> P a
+failSpanMsgP span msg = P $ \s -> PFailed span (text msg)
extension :: (Int -> Bool) -> P Bool
extension p = P $ \s -> POk s (p $! extsBitmap s)
setSrcLoc :: SrcLoc -> P ()
setSrcLoc new_loc = P $ \s -> POk s{loc=new_loc} ()
--- tmp, for supporting stuff in RdrHsSyn. The scope better not include
--- any calls to the lexer, because it assumes things about the SrcLoc.
-setSrcLocFor :: SrcLoc -> P a -> P a
-setSrcLocFor new_loc scope = P $ \s@PState{ loc = old_loc } ->
- case unP scope s{loc=new_loc} of
- PFailed l1 l2 msg -> PFailed l1 l2 msg
- POk _ r -> POk s r
-
getSrcLoc :: P SrcLoc
getSrcLoc = P $ \s@(PState{ loc=loc }) -> POk s loc
-setLastToken :: SrcLoc -> Int -> P ()
+setLastToken :: SrcSpan -> Int -> P ()
setLastToken loc len = P $ \s -> POk s{ last_loc=loc, last_len=len } ()
type AlexInput = (SrcLoc,StringBuffer)
mkPState buf loc flags =
PState {
buffer = buf,
- last_loc = loc,
+ last_loc = mkSrcSpan loc loc,
last_len = 0,
loc = loc,
extsBitmap = fromIntegral bitmap,
loc = loc, last_len = len, last_loc = last_loc }) ->
case ctx of
(_:tl) -> POk s{ context = tl } ()
- [] -> PFailed last_loc loc (srcParseErr buf len)
+ [] -> PFailed last_loc (srcParseErr buf len)
-- Push a new layout context at the indentation of the last token read.
-- This is only used at the outer level of a module when the 'module'
-- keyword is missing.
pushCurrentContext :: P ()
pushCurrentContext = P $ \ s@PState{ last_loc=loc, context=ctx } ->
- POk s{ context = Layout (srcLocCol loc) : ctx} ()
+ POk s{ context = Layout (srcSpanStartCol loc) : ctx} ()
getOffside :: SrcLoc -> P Ordering
getOffside loc = P $ \s@PState{context=stk} ->
srcParseFail :: P a
srcParseFail = P $ \PState{ buffer = buf, last_len = len,
last_loc = last_loc, loc = loc } ->
- PFailed last_loc loc (srcParseErr buf len)
+ PFailed last_loc (srcParseErr buf len)
-- A lexical error is reported at a particular position in the source file,
-- not over a token range. TODO: this is slightly wrong, because we record
lexError :: String -> P a
lexError str = do
loc <- getSrcLoc
- failLocMsgP loc loc str
+ i@(end,_) <- getInput
+ failLocMsgP loc end str
-- -----------------------------------------------------------------------------
-- This is the top-level function: called from the parser each time a
-- new token is to be read from the input.
-lexer :: (Token -> P a) -> P a
+lexer :: (Located Token -> P a) -> P a
lexer cont = do
- tok@(T _ _ tok__) <- lexToken
+ tok@(L _ tok__) <- lexToken
--trace ("token: " ++ show tok__) $ do
cont tok
-lexToken :: P Token
+lexToken :: P (Located Token)
lexToken = do
inp@(loc1,buf) <- getInput
sc <- getLexState
exts <- getExts
case alexScanUser exts inp sc of
- AlexEOF -> do setLastToken loc1 0
- return (T loc1 loc1 ITeof)
+ AlexEOF -> do let span = mkSrcSpan loc1 loc1
+ setLastToken span 0
+ return (L span ITeof)
AlexError (loc2,_) -> do failLocMsgP loc1 loc2 "lexical error"
AlexSkip inp2 _ -> do
setInput inp2
lexToken
AlexToken inp2@(end,buf2) len t -> do
setInput inp2
- setLastToken loc1 len
- t loc1 end buf len
+ let span = mkSrcSpan loc1 end
+ span `seq` setLastToken span len
+ t span buf len
}
projects / ghc-hetmet.git / blobdiff