Commit ff374b57 authored by simonmar's avatar simonmar
Browse files

[project @ 2003-11-12 14:54:32 by simonmar]

oops, committed wrong version of this file
parent 2b3f006b
......@@ -30,6 +30,7 @@ module Lexer (
#include "HsVersions.h"
import ForeignCall ( Safety(..) )
import ErrUtils ( Message )
import Outputable
import StringBuffer
......@@ -44,7 +45,7 @@ import Util ( maybePrefixMatch )
import DATA_BITS
import Char
import Ratio
--import TRACE
import TRACE
}
$whitechar = [\ \t\n\r\f\v\xa0]
......@@ -297,7 +298,7 @@ unsafeAt arr i = arr ! i
-- -----------------------------------------------------------------------------
-- The token type
data Token = T SrcSpan Token__
data Token = T SrcLoc{-start-} SrcLoc{-end-} Token__
data Token__
= ITas -- Haskell keywords
......@@ -541,39 +542,39 @@ reservedSymsFM = listToUFM $
-- -----------------------------------------------------------------------------
-- Lexer actions
type Action = SrcSpan -> StringBuffer -> Int -> P Token
type Action = SrcLoc -> SrcLoc -> StringBuffer -> Int -> P Token
special :: Token__ -> Action
special tok span _buf len = return (T span tok)
special tok loc end _buf len = return (T loc end tok)
token, layout_token :: Token__ -> Action
token t span buf len = return (T span t)
layout_token t span buf len = pushLexState layout >> return (T span t)
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)
idtoken :: (StringBuffer -> Int -> Token__) -> Action
idtoken f span buf len = return (T span $! (f buf len))
idtoken f loc end buf len = return (T loc end $! (f buf len))
skip_one_varid :: (FastString -> Token__) -> Action
skip_one_varid f span buf len
= return (T span $! f (lexemeToFastString (stepOn buf) (len-1)))
skip_one_varid f loc end buf len
= return (T loc end $! f (lexemeToFastString (stepOn buf) (len-1)))
strtoken :: (String -> Token__) -> Action
strtoken f span buf len =
return (T span $! (f $! lexemeToString buf len))
strtoken f loc end buf len =
return (T loc end $! (f $! lexemeToString buf len))
init_strtoken :: Int -> (String -> Token__) -> Action
-- like strtoken, but drops the last N character(s)
init_strtoken drop f span buf len =
return (T span $! (f $! lexemeToString buf (len-drop)))
init_strtoken drop f loc end buf len =
return (T loc end $! (f $! lexemeToString buf (len-drop)))
begin :: Int -> Action
begin code _span _str _len = do pushLexState code; lexToken
begin code _loc _end _str _len = do pushLexState code; lexToken
pop :: Action
pop _span _buf _len = do popLexState; lexToken
pop _loc _end _buf _len = do popLexState; lexToken
pop_and :: Action -> Action
pop_and act span buf len = do popLexState; act span buf len
pop_and act loc end buf len = do popLexState; act loc end buf len
notFollowedBy char _ _ _ (_,buf) = atEnd buf || currentChar buf /= char
......@@ -587,7 +588,7 @@ ifExtension pred bits _ _ _ = pred bits
using regular expressions.
-}
nested_comment :: Action
nested_comment span _str _len = do
nested_comment loc _end _str _len = do
input <- getInput
go 1 input
where go 0 input = do setInput input; lexToken
......@@ -608,21 +609,21 @@ nested_comment span _str _len = do
Just (c,input) -> go n input
c -> go n input
err input = do failLocMsgP (srcSpanStart span) (fst input) "unterminated `{-'"
err input = do failLocMsgP loc (fst input) "unterminated `{-'"
open_brace, close_brace :: Action
open_brace span _str _len = do
open_brace loc end _str _len = do
ctx <- getContext
setContext (NoLayout:ctx)
return (T span ITocurly)
close_brace span _str _len = do
return (T loc end ITocurly)
close_brace loc end _str _len = do
popContext
return (T span ITccurly)
return (T loc end 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 span buf len = do
check_qvarid loc end buf len = do
case lookupUFM reservedWordsFM var of
Just (keyword,exts)
| not (isSpecial keyword) ->
......@@ -635,10 +636,10 @@ check_qvarid span buf len = do
_other -> return token
where
(mod,var) = splitQualName buf len
token = T span (ITqvarid (mod,var))
token = T loc end (ITqvarid (mod,var))
try_again = do
setInput (srcSpanStart span,buf)
setInput (loc,buf)
pushLexState bad_qvarid
lexToken
......@@ -667,17 +668,17 @@ splitQualName orig_buf len = split orig_buf 0 0
(lexemeToFastString orig_buf dot_off,
lexemeToFastString (stepOnBy (dot_off+1) orig_buf) (len - dot_off -1))
varid span buf len =
varid loc end buf len =
case lookupUFM reservedWordsFM fs of
Just (keyword,0) -> do
maybe_layout keyword
return (T span keyword)
return (T loc end keyword)
Just (keyword,exts) -> do
b <- extension (\i -> exts .&. i /= 0)
if b then do maybe_layout keyword
return (T span keyword)
else return (T span (ITvarid fs))
_other -> return (T span (ITvarid fs))
return (T loc end keyword)
else return (T loc end (ITvarid fs))
_other -> return (T loc end (ITvarid fs))
where
fs = lexemeToFastString buf len
......@@ -690,34 +691,34 @@ qconsym buf len = ITqconsym $! splitQualName buf len
varsym = sym ITvarsym
consym = sym ITconsym
sym con span buf len =
sym con loc end buf len =
case lookupUFM reservedSymsFM fs of
Just (keyword,0) -> return (T span keyword)
Just (keyword,0) -> return (T loc end keyword)
Just (keyword,exts) -> do
b <- extension (\i -> exts .&. i /= 0)
if b then return (T span keyword)
else return (T span $! con fs)
_other -> return (T span $! con fs)
if b then return (T loc end keyword)
else return (T loc end $! con fs)
_other -> return (T loc end $! con fs)
where
fs = lexemeToFastString buf len
tok_decimal span buf len
= return (T span (ITinteger $! parseInteger buf len 10 oct_or_dec))
tok_decimal loc end buf len
= return (T loc end (ITinteger $! parseInteger buf len 10 oct_or_dec))
tok_octal span buf len
= return (T span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 8 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_hexadecimal span buf len
= return (T span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 16 hex))
tok_hexadecimal loc end buf len
= return (T loc end (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 16 hex))
prim_decimal span buf len
= return (T span (ITprimint $! parseInteger buf (len-1) 10 oct_or_dec))
prim_decimal loc end buf len
= return (T loc end (ITprimint $! parseInteger buf (len-1) 10 oct_or_dec))
prim_octal span buf len
= return (T span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 8 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_hexadecimal span buf len
= return (T span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 16 hex))
prim_hexadecimal loc end buf len
= return (T loc end (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 16 hex))
tok_float str = ITrational $! readRational__ str
prim_float str = ITprimfloat $! readRational__ str
......@@ -734,18 +735,18 @@ parseInteger buf len radix to_int
-- we're at the first token on a line, insert layout tokens if necessary
do_bol :: Action
do_bol span _str _len = do
pos <- getOffside (srcSpanEndCol span)
do_bol loc end _str _len = do
pos <- getOffside end
case pos of
LT -> do
--trace "layout: inserting '}'" $ do
popContext
-- do NOT pop the lex state, we might have a ';' to insert
return (T span ITvccurly)
return (T loc end ITvccurly)
EQ -> do
--trace "layout: inserting ';'" $ do
popLexState
return (T span ITsemi)
return (T loc end ITsemi)
GT -> do
popLexState
lexToken
......@@ -769,9 +770,9 @@ 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 strict span _buf _len = do
new_layout_context strict loc end _buf _len = do
popLexState
let offset = srcSpanStartCol span
let offset = srcLocCol loc
ctx <- getContext
case ctx of
Layout prev_off : _ |
......@@ -780,32 +781,32 @@ new_layout_context strict span _buf _len = do
-- token is indented to the left of the previous context.
-- we must generate a {} sequence now.
pushLexState layout_left
return (T span ITvocurly)
return (T loc end ITvocurly)
other -> do
setContext (Layout offset : ctx)
return (T span ITvocurly)
return (T loc end ITvocurly)
do_layout_left span _buf _len = do
do_layout_left loc end _buf _len = do
popLexState
pushLexState bol -- we must be at the start of a line
return (T span ITvccurly)
return (T loc end ITvccurly)
-- -----------------------------------------------------------------------------
-- LINE pragmas
set_line :: Int -> Action
set_line code span buf len = do
set_line code loc end buf len = do
let line = parseInteger buf len 10 oct_or_dec
setSrcLoc (mkSrcLoc (srcSpanFile span) (fromIntegral line - 1) 0)
setSrcLoc (mkSrcLoc (srcLocFile end) (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 span buf len = do
set_file code loc end buf len = do
let file = lexemeToFastString (stepOn buf) (len-2)
setSrcLoc (mkSrcLoc file (srcSpanEndLine span) (srcSpanEndCol span))
setSrcLoc (mkSrcLoc file (srcLocLine end) (srcLocCol end))
popLexState
pushLexState code
lexToken
......@@ -816,10 +817,10 @@ set_file code span buf len = do
-- This stuff is horrible. I hates it.
lex_string_tok :: Action
lex_string_tok span buf len = do
lex_string_tok loc end buf len = do
tok <- lex_string ""
end <- getSrcLoc
return (T (mkSrcSpan (srcSpanStart span) end) tok)
return (T loc end tok)
lex_string :: String -> P Token__
lex_string s = do
......@@ -857,6 +858,14 @@ lex_string s = do
c <- lex_char
lex_string (c:s)
lex_char :: P Char
lex_char = do
mc <- getCharOrFail
case mc of
'\\' -> lex_escape
c | is_any c -> return c
_other -> lit_error
lex_stringgap s = do
c <- getCharOrFail
case c of
......@@ -872,9 +881,8 @@ lex_char_tok :: Action
-- 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 '
lex_char_tok loc _end buf len = do -- We've seen '
i1 <- getInput -- Look ahead to first character
let loc = srcSpanStart span
case alexGetChar i1 of
Nothing -> lit_error
......@@ -882,7 +890,7 @@ lex_char_tok span buf len = do -- We've seen '
th_exts <- extension thEnabled
if th_exts then do
setInput i2
return (T (mkSrcSpan loc end2) ITtyQuote)
return (T loc end2 ITtyQuote)
else lit_error
Just ('\\', i2@(end2,_)) -> do -- We've seen 'backslash
......@@ -905,7 +913,7 @@ lex_char_tok span buf len = do -- We've seen '
_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 (T (mkSrcSpan loc (fst i1)) ITvarQuote)
if th_exts then return (T loc (fst i1) ITvarQuote)
else lit_error
finish_char_tok :: SrcLoc -> Char -> P Token
......@@ -917,20 +925,11 @@ finish_char_tok loc ch -- We've already seen the closing quote
case alexGetChar i of
Just ('#',i@(end,_)) -> do
setInput i
return (T (mkSrcSpan loc end) (ITprimchar ch))
return (T loc end (ITprimchar ch))
_other ->
return (T (mkSrcSpan loc end) (ITchar ch))
else do
end <- getSrcLoc
return (T (mkSrcSpan loc end) (ITchar ch))
lex_char :: P Char
lex_char = do
mc <- getCharOrFail
case mc of
'\\' -> lex_escape
c | is_any c -> return c
_other -> lit_error
return (T loc end (ITchar ch))
else do end <- getSrcLoc
return (T loc end (ITchar ch))
lex_escape :: P Char
lex_escape = do
......@@ -1114,26 +1113,24 @@ data LayoutContext
data ParseResult a
= POk PState a
| PFailed
SrcSpan -- The spam the error. Might be used in environments
-- which can show this span, e.g. by highlighting it.
SrcLoc SrcLoc -- 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 span err = hcat [ppr span, text ": ", err]
showPFailed loc1 loc2 err = hcat [ppr loc1, text ": ", err]
data PState = PState {
buffer :: StringBuffer,
last_span :: SrcSpan, -- span of previous token
last_len :: !Int,
last_loc :: SrcLoc, -- 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],
lex_state :: [Int]
}
-- last_span is used when generating error messages,
-- last_loc and last_len are used when generating error messages,
-- and in pushCurrentContext only.
-- last_len is used when generating error messages, and is
-- needed because we need to back up the buffer pointer by that
-- number of characters for outputing the token in the error message.
newtype P a = P { unP :: PState -> ParseResult a }
......@@ -1148,17 +1145,17 @@ returnP a = P $ \s -> POk s 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 span err -> PFailed span err
POk s1 a -> (unP (k a)) s1
PFailed l1 l2 err -> PFailed l1 l2 err
failP :: String -> P a
failP msg = P $ \s -> PFailed (last_span s) (text msg)
failP msg = P $ \s -> PFailed (last_loc s) (loc s) (text msg)
failMsgP :: String -> P a
failMsgP msg = P $ \s -> PFailed (last_span s) (text msg)
failMsgP msg = P $ \s -> PFailed (last_loc s) (loc s) (text msg)
failLocMsgP :: SrcLoc -> SrcLoc -> String -> P a
failLocMsgP loc1 loc2 str = P $ \s -> PFailed (mkSrcSpan loc1 loc2) (text str)
failLocMsgP loc1 loc2 str = P $ \s -> PFailed loc1 loc2 (text str)
extension :: (Int -> Bool) -> P Bool
extension p = P $ \s -> POk s (p $! extsBitmap s)
......@@ -1174,14 +1171,14 @@ setSrcLoc new_loc = P $ \s -> POk s{loc=new_loc} ()
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 span msg -> PFailed span msg
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 :: SrcSpan -> Int -> P ()
setLastToken span len = P $ \s -> POk s{ last_span=span, last_len=len } ()
setLastToken :: SrcLoc -> Int -> P ()
setLastToken loc len = P $ \s -> POk s{ last_loc=loc, last_len=len } ()
type AlexInput = (SrcLoc,StringBuffer)
......@@ -1237,7 +1234,7 @@ mkPState :: StringBuffer -> SrcLoc -> DynFlags -> PState
mkPState buf loc flags =
PState {
buffer = buf,
last_span = mkSrcSpan loc loc,
last_loc = loc,
last_len = 0,
loc = loc,
extsBitmap = fromIntegral bitmap,
......@@ -1265,24 +1262,24 @@ setContext ctx = P $ \s -> POk s{context=ctx} ()
popContext :: P ()
popContext = P $ \ s@(PState{ buffer = buf, context = ctx,
loc = loc, last_len = len, last_span = last_span }) ->
loc = loc, last_len = len, last_loc = last_loc }) ->
case ctx of
(_:tl) -> POk s{ context = tl } ()
[] -> PFailed last_span (srcParseErr buf len)
[] -> PFailed last_loc 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_span=span, context=ctx } ->
POk s{ context = Layout (srcSpanStartCol span) : ctx} ()
pushCurrentContext = P $ \ s@PState{ last_loc=loc, context=ctx } ->
POk s{ context = Layout (srcLocCol loc) : ctx} ()
getOffside :: Int -> P Ordering
getOffside col = P $ \s@PState{context=stk} ->
getOffside :: SrcLoc -> P Ordering
getOffside loc = P $ \s@PState{context=stk} ->
let ord = case stk of
(Layout n:_) -> compare col n
(Layout n:_) -> compare (srcLocCol loc) n
_ -> GT
in POk s $! ord
in POk s ord
-- ---------------------------------------------------------------------------
-- Construct a parse error
......@@ -1304,8 +1301,8 @@ srcParseErr buf len
-- detected during parsing.
srcParseFail :: P a
srcParseFail = P $ \PState{ buffer = buf, last_len = len,
last_span = last_span, loc = loc } ->
PFailed last_span (srcParseErr buf len)
last_loc = last_loc, loc = loc } ->
PFailed last_loc 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
......@@ -1322,7 +1319,7 @@ lexError str = do
lexer :: (Token -> P a) -> P a
lexer cont = do
tok@(T _ tok__) <- lexToken
tok@(T _ _ tok__) <- lexToken
--trace ("token: " ++ show tok__) $ do
cont tok
......@@ -1332,16 +1329,14 @@ lexToken = do
sc <- getLexState
exts <- getExts
case alexScanUser exts inp sc of
AlexEOF -> do let span = mkSrcSpan loc1 loc1
setLastToken span 0
return (T span ITeof)
AlexEOF -> do setLastToken loc1 0
return (T loc1 loc1 ITeof)
AlexError (loc2,_) -> do failLocMsgP loc1 loc2 "lexical error"
AlexSkip inp2 _ -> do
setInput inp2
lexToken
AlexToken inp2@(end,buf2) len t -> do
setInput inp2
let span = mkSrcSpan loc1 end
(setLastToken $! span) $! len
t span buf len
setLastToken loc1 len
t loc1 end buf len
}
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