{
module Lexer (
- Token(..), Token__(..), lexer, ExtFlags(..), mkPState, showPFailed,
- P(..), ParseResult(..), setSrcLocFor, getSrcLoc,
- failMsgP, failLocMsgP, srcParseFail,
- popContext, pushCurrentContext,
+ Token(..), lexer, mkPState, PState(..),
+ P(..), ParseResult(..), getSrcLoc,
+ failLocMsgP, failSpanMsgP, srcParseFail,
+ popContext, pushCurrentContext, setLastToken, setSrcLoc,
+ getLexState, popLexState, pushLexState
) where
#include "HsVersions.h"
-import ForeignCall ( Safety(..) )
import ErrUtils ( Message )
import Outputable
import StringBuffer
import FastTypes
import SrcLoc
import UniqFM
+import DynFlags
import Ctype
-import Util ( maybePrefixMatch )
+import Util ( maybePrefixMatch, readRational )
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
$ascdigit = 0-9
-- have to exclude those.
-- The regex says: "munch all the characters after the dashes, as long as
-- the first one is not a symbol".
-"--"\-* ([^$symbol] .*)? ;
+"--"\-* [^$symbol :] .* ;
+"--"\-* / { atEOL } ;
-- 'bol' state: beginning of a line. Slurp up all the whitespace (including
-- blank lines) until we find a non-whitespace character, then do layout
<bol> {
\n ;
^\# (line)? { begin line_prag1 }
+ ^\# pragma .* \n ; -- GCC 3.3 CPP generated, apparently
+ ^\# \! .* \n ; -- #!, for scripts
() { do_bol }
}
-- single-line line pragmas, of the form
-- # <line> "<file>" <extra-stuff> \n
-<line_prag1> $digit+ { set_line line_prag1a }
-<line_prag1a> \" [$graphic \ ]* \" { set_file line_prag1b }
+<line_prag1> $digit+ { setLine line_prag1a }
+<line_prag1a> \" [$graphic \ ]* \" { setFile line_prag1b }
<line_prag1b> .* { pop }
-- Haskell-style line pragmas, of the form
-- {-# LINE <line> "<file>" #-}
-<line_prag2> $digit+ { set_line line_prag2a }
-<line_prag2a> \" $graphic* \" { set_file line_prag2b }
-<line_prag2b> "#-}" { pop }
+<line_prag2> $digit+ { setLine line_prag2a }
+<line_prag2a> \" [$graphic \ ]* \" { setFile line_prag2b }
+<line_prag2b> "#-}"|"-}" { pop }
+ -- NOTE: accept -} at the end of a LINE pragma, for compatibility
+ -- with older versions of GHC which generated these.
+
+-- We only want RULES pragmas to be picked up when -fglasgow-exts
+-- is on, because the contents of the pragma is always written using
+-- glasgow-exts syntax (using forall etc.), so if glasgow exts are not
+-- enabled, we're sure to get a parse error.
+-- (ToDo: we should really emit a warning when ignoring pragmas)
+<glaexts>
+ "{-#" $whitechar* (RULES|rules) { token ITrules_prag }
<0,glaexts> {
+ "{-#" $whitechar* (INLINE|inline) { token (ITinline_prag True) }
+ "{-#" $whitechar* (NO(T?)INLINE|no(t?)inline)
+ { token (ITinline_prag False) }
+ "{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e)
+ { token ITspec_prag }
+ "{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e)
+ $whitechar* (INLINE|inline) { token (ITspec_inline_prag True) }
"{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e)
- { token ITspecialise_prag }
+ $whitechar* (NO(T?)INLINE|no(t?)inline)
+ { token (ITspec_inline_prag False) }
"{-#" $whitechar* (SOURCE|source) { token ITsource_prag }
- "{-#" $whitechar* (INLINE|inline) { token ITinline_prag }
- "{-#" $whitechar* (NO(T?)INLINE|no(t?)inline)
- { token ITnoinline_prag }
- "{-#" $whitechar* (RULES|rules) { token ITrules_prag }
"{-#" $whitechar* (DEPRECATED|deprecated)
{ token ITdeprecated_prag }
"{-#" $whitechar* (SCC|scc) { token ITscc_prag }
"{-#" $whitechar* (CORE|core) { token ITcore_prag }
+ "{-#" $whitechar* (UNPACK|unpack) { token ITunpack_prag }
"{-#" { nested_comment }
-- "special" symbols
+<0,glaexts> {
+ "[:" / { ifExtension parrEnabled } { token ITopabrack }
+ ":]" / { ifExtension parrEnabled } { token ITcpabrack }
+}
+
+<0,glaexts> {
+ "[|" / { ifExtension thEnabled } { token ITopenExpQuote }
+ "[e|" / { ifExtension thEnabled } { token ITopenExpQuote }
+ "[p|" / { ifExtension thEnabled } { token ITopenPatQuote }
+ "[d|" / { ifExtension thEnabled } { layout_token ITopenDecQuote }
+ "[t|" / { ifExtension thEnabled } { token ITopenTypQuote }
+ "|]" / { ifExtension thEnabled } { token ITcloseQuote }
+ \$ @varid / { ifExtension thEnabled } { skip_one_varid ITidEscape }
+ "$(" / { ifExtension thEnabled } { token ITparenEscape }
+}
+
+<0,glaexts> {
+ "(|" / { ifExtension arrowsEnabled `alexAndPred` notFollowedBySymbol }
+ { special IToparenbar }
+ "|)" / { ifExtension arrowsEnabled } { special ITcparenbar }
+}
+
+<0,glaexts> {
+ \? @varid / { ifExtension ipEnabled } { skip_one_varid ITdupipvarid }
+ \% @varid / { ifExtension ipEnabled } { skip_one_varid ITsplitipvarid }
+}
+
<glaexts> {
- "(#" { token IToubxparen }
+ "(#" / { notFollowedBySymbol } { token IToubxparen }
"#)" { token ITcubxparen }
-
- "[:" { token ITopabrack }
- ":]" { token ITcpabrack }
-
"{|" { token ITocurlybar }
"|}" { token ITccurlybar }
-
- "[|" { token ITopenExpQuote }
- "[e|" { token ITopenExpQuote }
- "[p|" { token ITopenPatQuote }
- "[d|" { layout_token ITopenDecQuote }
- "[t|" { token ITopenTypQuote }
- "|]" { token ITcloseQuote }
}
<0,glaexts> {
- "(|" / { \b _ _ _ -> arrowsEnabled b} { special IToparenbar }
- "|)" / { \b _ _ _ -> arrowsEnabled b} { special ITcparenbar }
\( { special IToparen }
\) { special ITcparen }
\[ { special ITobrack }
\} { close_brace }
}
-<glaexts> {
- \? @varid { skip_one_varid ITdupipvarid }
- \% @varid { skip_one_varid ITsplitipvarid }
- \$ @varid { skip_one_varid ITidEscape }
- "$(" { token ITparenEscape }
-}
-
<0,glaexts> {
@qual @varid { check_qvarid }
@qual @conid { idtoken qconid }
\" { lex_string_tok }
}
-<glaexts> "``" (([$graphic $whitechar] # \') | \' ([$graphic $whitechar] # \'))*
- "''" { clitlit }
-
{
-- work around bug in Alex 2.0
#if __GLASGOW_HASKELL__ < 503
-- -----------------------------------------------------------------------------
-- The token type
-data Token = T SrcLoc{-start-} SrcLoc{-end-} Token__
-
-data Token__
+data Token
= ITas -- Haskell keywords
| ITcase
| ITclass
| ITsafe
| ITthreadsafe
| ITunsafe
- | ITwith
| ITstdcallconv
| ITccallconv
| ITdotnet
- | ITccall (Bool,Bool,Safety) -- (is_dyn, is_casm, may_gc)
| ITmdo
- | ITspecialise_prag -- Pragmas
+ -- Pragmas
+ | ITinline_prag Bool -- True <=> INLINE, False <=> NOINLINE
+ | ITspec_prag -- SPECIALISE
+ | ITspec_inline_prag Bool -- SPECIALISE INLINE (or NOINLINE)
| ITsource_prag
- | ITinline_prag
- | ITnoinline_prag
| ITrules_prag
| ITdeprecated_prag
| ITline_prag
| ITscc_prag
| ITcore_prag -- hdaume: core annotations
+ | ITunpack_prag
| ITclose_prag
| ITdotdot -- reserved symbols
| ITprimint Integer
| ITprimfloat Rational
| ITprimdouble Rational
- | ITlitlit FastString
-- MetaHaskell extension tokens
- | ITopenExpQuote -- [| or [e|
- | ITopenPatQuote -- [p|
- | ITopenDecQuote -- [d|
- | ITopenTypQuote -- [t|
- | ITcloseQuote -- |]
- | ITidEscape FastString -- $x
- | ITparenEscape -- $(
- | ITreifyType
- | ITreifyDecl
- | ITreifyFixity
+ | ITopenExpQuote -- [| or [e|
+ | ITopenPatQuote -- [p|
+ | ITopenDecQuote -- [d|
+ | ITopenTypQuote -- [t|
+ | ITcloseQuote -- |]
+ | ITidEscape FastString -- $x
+ | ITparenEscape -- $(
+ | ITvarQuote -- '
+ | ITtyQuote -- ''
-- Arrow notation extension
| ITproc
| ITrec
- | IToparenbar -- (|
- | ITcparenbar -- |)
- | ITlarrowtail -- -<
- | ITrarrowtail -- >-
- | ITLarrowtail -- -<<
- | ITRarrowtail -- >>-
+ | IToparenbar -- (|
+ | ITcparenbar -- |)
+ | ITlarrowtail -- -<
+ | ITrarrowtail -- >-
+ | ITLarrowtail -- -<<
+ | ITRarrowtail -- >>-
| ITunknown String -- Used when the lexer can't make sense of it
| ITeof -- end of file token
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.
isSpecial ITsafe = True
isSpecial ITthreadsafe = True
isSpecial ITunsafe = True
-isSpecial ITwith = True
isSpecial ITccallconv = True
isSpecial ITstdcallconv = True
isSpecial ITmdo = True
( "where", ITwhere, 0 ),
( "_scc_", ITscc, 0 ), -- ToDo: remove
- ( "forall", ITforall, bit glaExtsBit),
+ ( "forall", ITforall, bit tvBit),
( "mdo", ITmdo, bit glaExtsBit),
- ( "reifyDecl", ITreifyDecl, bit glaExtsBit),
- ( "reifyType", ITreifyType, bit glaExtsBit),
- ( "reifyFixity",ITreifyFixity, bit glaExtsBit),
( "foreign", ITforeign, bit ffiBit),
( "export", ITexport, bit ffiBit),
( "ccall", ITccallconv, bit ffiBit),
( "dotnet", ITdotnet, bit ffiBit),
- ( "with", ITwith, bit withBit),
-
( "rec", ITrec, bit arrowsBit),
- ( "proc", ITproc, bit arrowsBit),
-
- -- On death row
- ("_ccall_", ITccall (False, False, PlayRisky),
- bit glaExtsBit),
- ("_ccall_GC_", ITccall (False, False, PlaySafe False),
- bit glaExtsBit),
- ("_casm_", ITccall (False, True, PlayRisky),
- bit glaExtsBit),
- ("_casm_GC_", ITccall (False, True, PlaySafe False),
- bit glaExtsBit)
+ ( "proc", ITproc, bit arrowsBit)
]
reservedSymsFM = listToUFM $
,("!", ITbang, 0)
,("*", ITstar, bit glaExtsBit) -- For data T (a::*) = MkT
- ,(".", ITdot, bit glaExtsBit) -- For 'forall a . t'
+ ,(".", ITdot, bit tvBit) -- For 'forall a . t'
,("-<", ITlarrowtail, bit arrowsBit)
,(">-", ITrarrowtail, bit arrowsBit)
-- -----------------------------------------------------------------------------
-- 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 $! lexemeToString buf (len-drop)))
begin :: Int -> Action
-begin code _loc _end _str _len = do pushLexState code; lexToken
+begin code _span _str _len = do pushLexState code; lexToken
pop :: Action
-pop _loc _end _buf _len = do popLexState; lexToken
+pop _span _buf _len = do popLexState; lexToken
pop_and :: Action -> Action
-pop_and act loc end buf len = do popLexState; act loc end buf len
+pop_and act span buf len = do popLexState; act span buf len
+
+notFollowedBy char _ _ _ (AI _ _ buf) = atEnd buf || currentChar buf /= char
+
+notFollowedBySymbol _ _ _ (AI _ _ buf)
+ = atEnd buf || currentChar buf `notElem` "!#$%&*+./<=>?@\\^|-~"
+
+atEOL _ _ _ (AI _ _ buf) = atEnd buf || currentChar buf == '\n'
-notFollowedBy char _ _ _ (_,buf) = atEnd buf || currentChar buf /= char
+ifExtension pred bits _ _ _ = pred bits
{-
nested comments require traversing by hand, they can't be parsed
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 (AI end _ _) = failLocMsgP (srcSpanStart span) end "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)
+ (AI _ offs _) <- getInput
+ setInput (AI (srcSpanStart span) (offs-len) 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 octDecDigit))
-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 octDecDigit))
-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 hexDigit))
-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 octDecDigit))
-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 octDecDigit))
-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 hexDigit))
-tok_float str = ITrational $! readRational__ str
-prim_float str = ITprimfloat $! readRational__ str
-prim_double str = ITprimdouble $! readRational__ str
-
-parseInteger :: StringBuffer -> Int -> Integer -> (Char->Int) -> Integer
-parseInteger buf len radix to_int
- = go 0 0
- where go i x | i == len = x
- | otherwise = go (i+1) (x * radix + toInteger (to_int (lookAhead buf i)))
-
-clitlit :: Action
-clitlit loc end buf len =
- return (T loc end (ITlitlit $! lexemeToFastString (stepOnBy 2 buf) (len-4)))
+tok_float str = ITrational $! readRational str
+prim_float str = ITprimfloat $! readRational str
+prim_double str = ITprimdouble $! readRational str
-- -----------------------------------------------------------------------------
-- Layout processing
-- 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
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
+ (AI _ offset _) <- getInput
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
- let line = parseInteger buf len 10 oct_or_dec
- setSrcLoc (mkSrcLoc (srcLocFile end) (fromIntegral line - 1) 0)
+setLine :: Int -> Action
+setLine code span buf len = do
+ let line = parseInteger buf len 10 octDecDigit
+ 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
+setFile :: Int -> Action
+setFile 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
- Just ('#',i@(end,_)) -> do
+-- 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@(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
+
+ Just ('\\', i2@(AI 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@(AI 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
+ let (AI end _ _) = i1
+ if th_exts then return (L (mkSrcSpan loc end) 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@(AI end _ _) <- getInput
+ if glaexts then do
+ case alexGetChar i of
+ Just ('#',i@(AI 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
then return (chr (ord c - ord '@'))
else lit_error
- 'x' -> readNum is_hexdigit 16 hex
- 'o' -> readNum is_octdigit 8 oct_or_dec
- x | is_digit x -> readNum2 is_digit 10 oct_or_dec (oct_or_dec x)
+ 'x' -> readNum is_hexdigit 16 hexDigit
+ 'o' -> readNum is_octdigit 8 octDecDigit
+ x | is_digit x -> readNum2 is_digit 10 octDecDigit (octDecDigit x)
c1 -> do
i <- getInput
then return (chr i)
else lit_error
-is_hexdigit c
- = is_digit c
- || (c >= 'a' && c <= 'f')
- || (c >= 'A' && c <= 'F')
-
-hex c | is_digit c = ord c - ord '0'
- | otherwise = ord (to_lower c) - ord 'a' + 10
-
-oct_or_dec c = ord c - ord '0'
-
-is_octdigit c = c >= '0' && c <= '7'
-
-to_lower c
- | c >= 'A' && c <= 'Z' = chr (ord c - (ord 'A' - ord 'a'))
- | otherwise = c
-
silly_escape_chars = [
("NUL", '\NUL'),
("SOH", '\SOH'),
Just (c,i) -> do setInput i; return c
-- -----------------------------------------------------------------------------
--- Floats
-
-readRational :: ReadS Rational -- NB: doesn't handle leading "-"
-readRational r = do
- (n,d,s) <- readFix r
- (k,t) <- readExp s
- return ((n%1)*10^^(k-d), t)
- where
- readFix r = do
- (ds,s) <- lexDecDigits r
- (ds',t) <- lexDotDigits s
- return (read (ds++ds'), length ds', t)
-
- readExp (e:s) | e `elem` "eE" = readExp' s
- readExp s = return (0,s)
-
- readExp' ('+':s) = readDec s
- readExp' ('-':s) = do
- (k,t) <- readDec s
- return (-k,t)
- readExp' s = readDec s
-
- readDec s = do
- (ds,r) <- nonnull isDigit s
- return (foldl1 (\n d -> n * 10 + d) [ ord d - ord '0' | d <- ds ],
- r)
-
- lexDecDigits = nonnull isDigit
-
- lexDotDigits ('.':s) = return (span isDigit s)
- lexDotDigits s = return ("",s)
-
- nonnull p s = do (cs@(_:_),t) <- return (span p s)
- return (cs,t)
-
-readRational__ :: String -> Rational -- NB: *does* handle a leading "-"
-readRational__ top_s
- = case top_s of
- '-' : xs -> - (read_me xs)
- xs -> read_me xs
- where
- read_me s
- = case (do { (x,"") <- readRational s ; return x }) of
- [x] -> x
- [] -> error ("readRational__: no parse:" ++ top_s)
- _ -> error ("readRational__: ambiguous parse:" ++ top_s)
-
--- -----------------------------------------------------------------------------
-- The Parse Monad
data LayoutContext
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
- = showSDoc (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_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
loc :: SrcLoc, -- current loc (end of prev token + 1)
extsBitmap :: !Int, -- bitmap that determines permitted extensions
context :: [LayoutContext],
lex_state :: [Int]
}
-- last_loc and last_len are used when generating error messages,
- -- and in pushCurrentContext only.
+ -- and in pushCurrentContext only. Sigh, if only Happy passed the
+ -- current token to happyError, we could at least get rid of last_len.
+ -- Getting rid of last_loc would require finding another way to
+ -- implement pushCurrentContext (which is only called from one place).
newtype P a = P { unP :: PState -> ParseResult a }
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)
+data AlexInput = AI SrcLoc {-#UNPACK#-}!Int StringBuffer
alexInputPrevChar :: AlexInput -> Char
-alexInputPrevChar (_,s) = prevChar s '\n'
+alexInputPrevChar (AI _ _ s) = prevChar s '\n'
alexGetChar :: AlexInput -> Maybe (Char,AlexInput)
-alexGetChar (loc,s)
+alexGetChar (AI loc ofs s)
| atEnd s = Nothing
- | otherwise = c `seq` loc' `seq` s' `seq` Just (c, (loc', s'))
- where c = currentChar s
+ | otherwise = c `seq` loc' `seq` ofs' `seq` s' `seq` Just (c, (AI loc' ofs' s'))
+ where c = currentChar s
loc' = advanceSrcLoc loc c
+ ofs' = advanceOffs c ofs
s' = stepOn s
+ advanceOffs :: Char -> Int -> Int
+ advanceOffs '\n' offs = 0
+ advanceOffs '\t' offs = (offs `quot` 8 + 1) * 8
+ advanceOffs _ offs = offs + 1
+
getInput :: P AlexInput
-getInput = P $ \s@PState{ loc=l, buffer=b } -> POk s (l,b)
+getInput = P $ \s@PState{ loc=l, last_offs=o, buffer=b } -> POk s (AI l o b)
setInput :: AlexInput -> P ()
-setInput (l,b) = P $ \s -> POk s{ loc=l, buffer=b } ()
+setInput (AI l o b) = P $ \s -> POk s{ loc=l, last_offs=o, buffer=b } ()
pushLexState :: Int -> P ()
pushLexState ls = P $ \s@PState{ lex_state=l } -> POk s{lex_state=ls:l} ()
glaExtsBit = 0
ffiBit = 1
parrBit = 2
-withBit = 3
arrowsBit = 4
+thBit = 5
+ipBit = 6
+tvBit = 7 -- Scoped type variables enables 'forall' keyword
glaExtsEnabled, ffiEnabled, parrEnabled :: Int -> Bool
glaExtsEnabled flags = testBit flags glaExtsBit
ffiEnabled flags = testBit flags ffiBit
-withEnabled flags = testBit flags withBit
parrEnabled flags = testBit flags parrBit
arrowsEnabled flags = testBit flags arrowsBit
-
--- convenient record-based bitmap for the interface to the rest of the world
---
--- NB: `glasgowExtsEF' implies `ffiEF' (see `mkPState' below)
---
-data ExtFlags = ExtFlags {
- glasgowExtsEF :: Bool,
- ffiEF :: Bool,
- withEF :: Bool,
- parrEF :: Bool,
- arrowsEF :: Bool
- }
+thEnabled flags = testBit flags thBit
+ipEnabled flags = testBit flags ipBit
+tvEnabled flags = testBit flags tvBit
-- create a parse state
--
-mkPState :: StringBuffer -> SrcLoc -> ExtFlags -> PState
-mkPState buf loc exts =
+mkPState :: StringBuffer -> SrcLoc -> DynFlags -> PState
+mkPState buf loc flags =
PState {
buffer = buf,
- last_loc = loc,
+ last_loc = mkSrcSpan loc loc,
+ last_offs = 0,
last_len = 0,
loc = loc,
extsBitmap = fromIntegral bitmap,
-- we begin in the layout state if toplev_layout is set
}
where
- bitmap = glaExtsBit `setBitIf` glasgowExtsEF exts
- .|. ffiBit `setBitIf` (ffiEF exts
- || glasgowExtsEF exts)
- .|. withBit `setBitIf` withEF exts
- .|. parrBit `setBitIf` parrEF exts
- .|. arrowsBit `setBitIf` arrowsEF exts
+ bitmap = glaExtsBit `setBitIf` dopt Opt_GlasgowExts flags
+ .|. ffiBit `setBitIf` dopt Opt_FFI flags
+ .|. parrBit `setBitIf` dopt Opt_PArr flags
+ .|. arrowsBit `setBitIf` dopt Opt_Arrows flags
+ .|. thBit `setBitIf` dopt Opt_TH flags
+ .|. ipBit `setBitIf` dopt Opt_ImplicitParams flags
+ .|. tvBit `setBitIf` dopt Opt_ScopedTypeVariables flags
--
setBitIf :: Int -> Bool -> Int
b `setBitIf` cond | cond = bit b
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} ()
+pushCurrentContext = P $ \ s@PState{ last_offs=offs, last_len=len, context=ctx } ->
+ POk s{context = Layout (offs-len) : ctx} ()
-getOffside :: SrcLoc -> P Ordering
-getOffside loc = P $ \s@PState{context=stk} ->
+getOffside :: P Ordering
+getOffside = P $ \s@PState{last_offs=offs, context=stk} ->
let ord = case stk of
- (Layout n:_) -> compare (srcLocCol loc) n
+ (Layout n:_) -> compare offs n
_ -> GT
in POk s ord
-- detected during parsing.
srcParseFail :: P a
srcParseFail = P $ \PState{ buffer = buf, last_len = len,
- last_loc = last_loc, loc = loc } ->
- PFailed last_loc loc (srcParseErr buf len)
+ last_loc = last_loc } ->
+ 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@(AI 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
- --trace ("token: " ++ show tok__) $ do
+ tok@(L _ tok__) <- lexToken
+ -- trace ("token: " ++ show tok__) $ do
cont tok
-lexToken :: P Token
+lexToken :: P (Located Token)
lexToken = do
- inp@(loc1,buf) <- getInput
+ inp@(AI loc1 _ buf) <- getInput
sc <- getLexState
exts <- getExts
case alexScanUser exts inp sc of
- AlexEOF -> do setLastToken loc1 0
- return (T loc1 loc1 ITeof)
- AlexError (loc2,_) -> do failLocMsgP loc1 loc2 "lexical error"
+ AlexEOF -> do let span = mkSrcSpan loc1 loc1
+ setLastToken span 0
+ return (L span ITeof)
+ AlexError (AI loc2 _ _) -> do failLocMsgP loc1 loc2 "lexical error"
AlexSkip inp2 _ -> do
setInput inp2
lexToken
- AlexToken inp2@(end,buf2) len t -> do
+ AlexToken inp2@(AI 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
}