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Diffstat (limited to 'src/HsLexer.lhs')
| -rw-r--r-- | src/HsLexer.lhs | 713 |
1 files changed, 0 insertions, 713 deletions
diff --git a/src/HsLexer.lhs b/src/HsLexer.lhs deleted file mode 100644 index 93baa6aa..00000000 --- a/src/HsLexer.lhs +++ /dev/null @@ -1,713 +0,0 @@ ------------------------------------------------------------------------------ --- $Id: HsLexer.lhs,v 1.18 2005/03/09 08:28:39 wolfgang Exp $ --- --- (c) The GHC Team, 1997-2000 --- --- Lexer for Haskell. --- ------------------------------------------------------------------------------ - -ToDo: Parsing floats is a *real* hack... -ToDo: Introduce different tokens for decimal, octal and hexadecimal (?) -ToDo: FloatTok should have three parts (integer part, fraction, exponent) -ToDo: Use a lexical analyser generator (lx?) - -\begin{code} -module HsLexer (Token(..), lexer, parseError,isSymbol) where - -import HsParseMonad -import HsParseUtils -import HsSyn2 - -import Numeric ( readHex, readOct ) -import Char -import List ( isPrefixOf ) -\end{code} - -\begin{code} -data Token - = VarId String - | IPVarId String - | QVarId (String,String) - | ConId String - | QConId (String,String) - | VarSym String - | ConSym String - | QVarSym (String,String) - | QConSym (String,String) - --- Literals - - | IntTok Integer - | FloatTok String - | Character Char - | StringTok String - | PrimChar Char -- GHC extension - | PrimInt Integer -- GHC extension - | PrimString String -- GHC extension - | PrimFloat String -- GHC extension - | PrimDouble String -- GHC extension - --- Symbols - - | LeftParen - | RightParen - | SemiColon - | LeftCurly - | RightCurly - | VRightCurly -- a virtual close brace - | LeftSquare - | RightSquare - | Comma - | Underscore - | BackQuote - | LeftUT -- GHC Extension: (# - | RightUT -- GHC Extension: #) - --- Documentation annotations - - | DocCommentNext String -- something beginning '-- |' - | DocCommentPrev String -- something beginning '-- ^' - | DocCommentNamed String -- something beginning '-- $' - | DocSection Int String -- a section heading - | DocOptions String -- attributes '-- #' - --- Reserved operators - - | Dot -- GHC extension - | DotDot - | DoubleColon - | Equals - | Backslash - | Bar - | LeftArrow - | RightArrow - | At - | Tilde - | DoubleArrow - | Minus - | Exclamation - --- Reserved Ids - - | KW_As - | KW_Case - | KW_CCall - | KW_Class - | KW_Data - | KW_Default - | KW_Deriving - | KW_Do - | KW_DotNet - | KW_Else - | KW_Export - | KW_Forall - | KW_Foreign - | KW_Hiding - | KW_If - | KW_Import - | KW_In - | KW_Infix - | KW_InfixL - | KW_InfixR - | KW_Instance - | KW_Let - | KW_Module - | KW_NewType - | KW_Of - | KW_Safe - | KW_StdCall - | KW_Then - | KW_ThreadSafe - | KW_Type - | KW_Unsafe - | KW_Where - | KW_Qualified - - | EOF - deriving (Eq,Show) - -reserved_ops :: [(String,Token)] -reserved_ops = [ - ( ".", Dot ), -- GHC extension - ( "..", DotDot ), - ( "::", DoubleColon ), - ( "=", Equals ), - ( "\\", Backslash ), - ( "|", Bar ), - ( "<-", LeftArrow ), - ( "->", RightArrow ), - ( "@", At ), - ( "~", Tilde ), - ( "=>", DoubleArrow ), - ( "-", Minus ), --ToDo: shouldn't be here - ( "!", Exclamation ) --ditto - ] - -reserved_ids :: [(String,Token)] -reserved_ids = [ - ( "_", Underscore ), - ( "case", KW_Case ), - ( "ccall", KW_CCall ), - ( "class", KW_Class ), - ( "data", KW_Data ), - ( "default", KW_Default ), - ( "deriving", KW_Deriving ), - ( "do", KW_Do ), - ( "dotnet", KW_DotNet ), - ( "else", KW_Else ), - ( "export", KW_Export ), - ( "forall", KW_Forall ), - ( "foreign", KW_Foreign ), - ( "if", KW_If ), - ( "import", KW_Import ), - ( "in", KW_In ), - ( "infix", KW_Infix ), - ( "infixl", KW_InfixL ), - ( "infixr", KW_InfixR ), - ( "instance", KW_Instance ), - ( "let", KW_Let ), - ( "mdo", KW_Do ), -- pretend mdo is do, for now. - ( "module", KW_Module ), - ( "newtype", KW_NewType ), - ( "of", KW_Of ), - ( "safe", KW_Safe ), - ( "then", KW_Then ), - ( "threadsafe",KW_ThreadSafe ), - ( "type", KW_Type ), - ( "unsafe", KW_Unsafe ), - ( "where", KW_Where ), - ( "as", KW_As ), - ( "qualified", KW_Qualified ), - ( "hiding", KW_Hiding ), - ( "stdcall", KW_StdCall ) - ] - -specialIds = [ - KW_As, - KW_Unsafe, - KW_Safe, - KW_ThreadSafe, - KW_Qualified, - KW_Hiding, - KW_Export, - KW_StdCall, - KW_CCall, - KW_DotNet - ] - -isIdent, isSymbol, isWhite :: Char -> Bool -isIdent c = isAlpha c || isDigit c || c == '\'' || c == '_' -isSymbol c = elem c ":!#$%&*+./<=>?@\\^|-~" -isWhite c = elem c " \n\r\t\v\f" - -isIdentInitial :: Char -> Bool -isIdentInitial ch = isLower ch || ch == '_' - -tAB_LENGTH :: Int -tAB_LENGTH = 8 - --- The source location, (y,x), is the coordinates of the previous token. --- col is the current column in the source file. If col is 0, we are --- somewhere at the beginning of the line before the first token. - --- Setting col to 0 is used in two places: just after emitting a virtual --- close brace due to layout, so that next time through we check whether --- we also need to emit a semi-colon, and at the beginning of the file, --- to kick off the lexer. - - -lexer :: (Token -> P a) -> P a -lexer cont input (SrcLoc _ x0 _) y0 col f = - if col == 0 - then tab y0 x0 f True input - else tab y0 col f False input -- throw away old x - where - -- move past whitespace and comments - tab y x f _ [] = - cont EOF [] (SrcLoc y x f) y col f - tab y x f bol ('\t':s) = - tab y (nextTab x) f bol s - tab y _ f _ ('\n':s) = - newLine cont s y f - - tab y _ f True ('#':s) - | "pragma GCC set_debug_pwd" `isPrefixOf` s - = newLine cont (tail $ dropWhile (/= '\n') s) y f - - tab y x f True ('#':' ':s@(d:_)) - | isDigit d = parseLinePragma tab y f s - - -- single-line comments - tab y x f bol s@('-':'-':' ':c:_) | doc c = - is_a_token bol s y x f - tab y _ f _ ('-':'-':s) | null s || not (isSymbol (head (dropWhile (== '-') s))) = - newLine cont (drop 1 (dropWhile (/= '\n') s)) y f - - -- multi-line nested comments and pragmas - tab y x f bol ('{':'-':'#':s) = pragma tab y (x+3) f bol s - tab y x f bol s@('{':'-':c:_) | doc c = - is_a_token bol s y x f - tab y x f bol s@('{':'-':' ':c:_) | doc c = - is_a_token bol s y x f - tab y x f bol ('{':'-':s) = nestedComment (\y x -> tab y x f) y (x+2) bol s - - tab y x f bol (c:s) - | isWhite c = tab y (x+1) f bol s - | otherwise = is_a_token bol (c:s) y x f - - is_a_token bol s y x f - | bol = lexBOL cont s (SrcLoc y x f) y x f - | otherwise = lexToken cont s (SrcLoc y x f) y x f - - newLine _ s y f = tab (y+1) 1 f True s - - doc '|' = True - doc '/' = True - doc '^' = True - doc '*' = True - doc '$' = True - doc '#' = True - doc _ = False - -nextTab :: Int -> Int -nextTab x = x + (tAB_LENGTH - (x-1) `mod` tAB_LENGTH) - --- When we are lexing the first token of a line, check whether we need to --- insert virtual semicolons or close braces due to layout. - -lexBOL :: (Token -> P a) -> P a -lexBOL cont s loc y x f context = - if need_close_curly then - -- trace "layout: inserting '}'\n" $ - -- Set col to 0, indicating that we're still at the - -- beginning of the line, in case we need a semi-colon too. - -- Also pop the context here, so that we don't insert - -- another close brace before the parser can pop it. - cont VRightCurly s loc y 0 f (tail context) - else if need_semi_colon then - --trace "layout: inserting ';'\n" $ - cont SemiColon s loc y x f context - else - lexToken cont s loc y x f context - where - need_close_curly = - case context of - [] -> False - (i:_) -> case i of - NoLayout -> False - Layout n -> x < n - need_semi_colon = - case context of - [] -> False - (i:_) -> case i of - NoLayout -> False - Layout n -> x == n - -lexToken :: (Token -> P a) -> P a ---lexToken _ [] loc _ _ = --- error $ "Internal error: empty input in lexToken at " ++ show loc -lexToken cont s0 loc y x f = - -- trace ("lexer: y="++show y++" x="++show x++"\n") $ - case s0 of - [] -> error $ "Internal error: empty input in lexToken at " - ++ show loc - -- First the doc comments - '-':'-':' ':s -> do_doc s False - '{':'-':' ':s -> do_doc s True - '{':'-':s -> do_doc s True - - -- Next the special symbols - '(':'#':s -> forward 2 LeftUT s - '(':s -> forward 1 LeftParen s - '#':')':s -> forward 2 RightUT s - ')':s -> forward 1 RightParen s - ',':s -> forward 1 Comma s - ';':s -> forward 1 SemiColon s - '[':s -> forward 1 LeftSquare s - ']':s -> forward 1 RightSquare s - '`':s -> forward 1 BackQuote s - '{':s -> \ctxt -> forward 1 LeftCurly s (NoLayout : ctxt) - '}':s -> \ctxt0 -> case ctxt0 of - (_:ctxt) -> forward 1 RightCurly s ctxt - -- pop context on '}' - [] -> error "Internal error: empty context in lexToken" - - '?':s:ss - | isIdentInitial s -> lexToken ( \ (VarId x) -> cont (IPVarId x)) (s:ss) loc y x f - '\'':s -> lexChar cont s loc y (x+1) f - '\"':s{-"-} -> lexString cont s loc y (x+1) f - - '0':'x':c:s | isHexDigit c -> - let (num, rest) = span isHexDigit (c:s) - [(i,_)] = readHex num - in - afterNum cont i rest loc y (x+length num) f - '0':'o':c:s | isOctDigit c -> - let (num, rest) = span isOctDigit (c:s) - [(i,_)] = readOct num - in - afterNum cont i rest loc y (x+length num) f - - c:s | isIdentInitial c -> - let - (idtail, rest) = slurpIdent s - id0 = c:idtail - l_id = 1 + length idtail - in - case lookup id0 reserved_ids of - Just keyword -> forward l_id keyword rest - Nothing -> forward l_id (VarId id0) rest - - | isUpper c -> lexCon "" cont (c:s) loc y x f - | isSymbol c -> - let - (symtail, rest) = span isSymbol s - sym = c : symtail - l_sym = 1 + length symtail - in - case lookup sym reserved_ops of - Just t -> forward l_sym t rest - Nothing -> case c of - ':' -> forward l_sym (ConSym sym) rest - _ -> forward l_sym (VarSym sym) rest - - | isDigit c -> lexNum cont c s loc y x f - - | otherwise -> - parseError ("illegal character \'" ++ show c ++ "\'\n") - s loc y x f - - where forward n t str = cont t str loc y (x+n) f - - -- this is all terribly ugly, sorry :( - do_doc ('|':s) nested = multi nested DocCommentNext cont s loc y x f - do_doc ('/':s) nested = multi nested DocCommentNext cont s loc y x f - do_doc ('^':s) nested = multi nested DocCommentPrev cont s loc y x f - do_doc ('$':s) nested = multi nested DocCommentNamed cont s loc y x f - do_doc ('#':s) nested = multi nested DocOptions cont s loc y x f - do_doc ('*':s) nested = section 1 s - where section n ('*':s1) = section (n+1) s1 - section n s1 - | nested = nestedDocComment (DocSection n) cont s1 loc y x f - | otherwise = oneLineDocComment (DocSection n) cont s1 loc y x f - do_doc _ _ = error "Internal error: HsLexer.do_doc" - - -multi :: Bool -> ([Char] -> b) - -> (b -> [Char] -> c -> Int -> Int -> d) - -> [Char] -> c -> Int -> Int -> d -multi True = nestedDocComment -multi False = multiLineDocComment - -afterNum :: Num a => (Token -> [Char] -> b -> c -> a -> d -> e) - -> Integer -> [Char] -> b -> c -> a -> d -> e -afterNum cont i ('#':s) loc y x f = cont (PrimInt i) s loc y (x+1) f -afterNum cont i s loc y x f = cont (IntTok i) s loc y x f - -lexNum :: (Token -> [Char] -> a -> b -> Int -> c -> d) - -> Char -> [Char] -> a -> b -> Int -> c -> d -lexNum cont c0 s0 loc y x fname = - let (num, after_num) = span isDigit (c0:s0) - in - case after_num of - '.':c1:s1 | isDigit c1 -> - let (frac,after_frac) = span isDigit s1 - in - let float = num ++ '.':frac - (f, after_exp) - = case after_frac of - 'E':s -> do_exponent s - 'e':s -> do_exponent s - _ -> (float, after_frac) - - do_exponent s2 = - case s2 of - '-':c:s | isDigit c -> - let (exp0,rest) = span isDigit (c:s) in - (float ++ 'e':'-':exp0, rest) - '+':c:s | isDigit c -> - let (exp0,rest) = span isDigit (c:s) in - (float ++ 'e':'+':exp0, rest) - c:s | isDigit c -> - let (exp0,rest) = span isDigit (c:s) in - (float ++ 'e':exp0, rest) - _ -> (float, after_frac) - - x' = x + length f - - in case after_exp of -- glasgow exts only - '#':'#':s -> cont (PrimDouble f) s loc y x' fname - '#':s -> cont (PrimFloat f) s loc y x' fname - s -> cont (FloatTok f) s loc y x' fname - - _ -> afterNum cont (parseInteger 10 num) after_num loc y (x + length num) fname - - --- GHC extension: allow trailing '#'s in an identifier. -slurpIdent :: String -> (String, String) -slurpIdent s = slurp' s [] - where - slurp' [] i = (reverse i, []) - slurp' (c:cs) i - | isIdent c = slurp' cs (c:i) - | c == '#' = slurphashes cs (c:i) - slurp' cs i = (reverse i, cs) - -slurphashes :: String -> String -> (String, String) -slurphashes [] i = (reverse i, []) -slurphashes ('#':cs) i = slurphashes cs ('#':i) -slurphashes s i = (reverse i, s) - -lexCon :: [Char] -> (Token -> String -> a -> b -> Int -> c -> d) - -> String -> a -> b -> Int -> c -> d -lexCon qual cont s0 loc y x f = - let - forward n t s = cont t s loc y (x+n) f - - (con, rest) = slurpIdent s0 - l_con = length con - - just_a_conid - | null qual = forward l_con (ConId con) rest - | otherwise = forward l_con (QConId (qual,con)) rest - - qual' | null qual = con - | otherwise = qual ++ '.':con - in - case rest of - '.':c1:s1 - | isIdentInitial c1 -> -- qualified varid? - let - (idtail, rest1) = slurpIdent s1 - id0 = c1:idtail - l_id = 1 + length idtail - in - case lookup id0 reserved_ids of - -- cannot qualify a reserved word - Just id | id `notElem` specialIds -> just_a_conid - _ -> forward (l_con+1+l_id) (QVarId (qual', id0)) rest1 - - | isUpper c1 -> -- qualified conid? - lexCon qual' cont (c1:s1) loc y (x+l_con+1) f - - | isSymbol c1 -> -- qualified symbol? - let - (symtail, rest1) = span isSymbol s1 - sym = c1 : symtail - l_sym = 1 + length symtail - in - case lookup sym reserved_ops of - -- cannot qualify a reserved operator - Just _ -> just_a_conid - Nothing -> - case c1 of - ':' -> forward (l_con+1+l_sym) (QConSym (qual', sym)) rest1 - _ -> forward (l_con+1+l_sym) (QVarSym (qual', sym)) rest1 - - _ -> just_a_conid -- not a qualified thing - - -lexChar :: (Token -> P a) -> P a -lexChar cont s0 loc0 y x f = case s0 of - '\\':s1 -> (escapeChar s1 `thenP` \(e,s,i) _ _ _ _ _ -> - charEnd e s loc0 y (x+i) f) s1 loc0 y x f - c:s -> charEnd c s loc0 y (x+1) f - [] -> char_err [] loc0 y x f - - where charEnd c ('\'':'#':s) = \loc y0 x0 f0 -> cont (PrimChar c) s loc y0 (x0+2) f0 - charEnd c ('\'':s) = \loc y0 x0 f0 -> cont (Character c) s loc y0 (x0+1) f0 - charEnd c s = char_err s - - char_err s = parseError "Improperly terminated character constant" s - -lexString :: (Token -> P a) -> P a -lexString cont s0 loc y0 x0 f0 = loop "" s0 x0 y0 f0 - where - loop e s1 x y f = case s1 of - '\\':'&':s -> loop e s (x+2) y f - '\\':c:s | isSpace c -> stringGap e s (x+2) y f - | otherwise -> (escapeChar (c:s) `thenP` \(e',s2,i) _ _ _ _ -> - loop (e':e) s2 (x+i) y) s loc y x f - '\"':'#':s -> cont (PrimString (reverse e)) s loc y (x+2) f - '\"':s{-"-} -> cont (StringTok (reverse e)) s loc y (x+1) f - c:s -> loop (c:e) s (x+1) y f - [] -> parseError "Improperly terminated string" s1 loc y x f - - stringGap e s1 x y = case s1 of - '\n':s -> stringGap e s 1 (y+1) - '\\':s -> loop e s (x+1) y - c:s | isSpace c -> stringGap e s (x+1) y - | otherwise -> - parseError "Illegal character in string gap" s1 loc y x - [] -> error "Internal error: stringGap" - --- ToDo: \o, \x, \<octal> things. - -escapeChar :: String -> P (Char,String,Int) -escapeChar s0 = case s0 of - - 'x':c:s | isHexDigit c -> - let (num,rest) = span isHexDigit (c:s) in - returnP (chr (fromIntegral (parseInteger 16 num)), rest, length num) - - 'o':c:s | isOctDigit c -> - let (num,rest) = span isOctDigit (c:s) in - returnP (chr (fromIntegral (parseInteger 8 num)), rest, length num) - - c:s | isDigit c -> let (num,rest) = span isDigit (c:s) in - returnP (chr (read num), rest, length num) - --- Production charesc from section B.2 (Note: \& is handled by caller) - - 'a':s -> returnP ('\a',s,2) - 'b':s -> returnP ('\b',s,2) - 'f':s -> returnP ('\f',s,2) - 'n':s -> returnP ('\n',s,2) - 'r':s -> returnP ('\r',s,2) - 't':s -> returnP ('\t',s,2) - 'v':s -> returnP ('\v',s,2) - '\\':s -> returnP ('\\',s,2) - '"':s -> returnP ('\"',s,2) - '\'':s -> returnP ('\'',s,2) - --- Production ascii from section B.2 - - '^':x@(_:_) -> cntrl x - 'N':'U':'L':s -> returnP ('\NUL',s,4) - 'S':'O':'H':s -> returnP ('\SOH',s,4) - 'S':'T':'X':s -> returnP ('\STX',s,4) - 'E':'T':'X':s -> returnP ('\ETX',s,4) - 'E':'O':'T':s -> returnP ('\EOT',s,4) - 'E':'N':'Q':s -> returnP ('\ENQ',s,4) - 'A':'C':'K':s -> returnP ('\ACK',s,4) - 'B':'E':'L':s -> returnP ('\BEL',s,4) - 'B':'S':s -> returnP ('\BS', s,3) - 'H':'T':s -> returnP ('\HT', s,3) - 'L':'F':s -> returnP ('\LF', s,3) - 'V':'T':s -> returnP ('\VT', s,3) - 'F':'F':s -> returnP ('\FF', s,3) - 'C':'R':s -> returnP ('\CR', s,3) - 'S':'O':s -> returnP ('\SO', s,3) - 'S':'I':s -> returnP ('\SI', s,3) - 'D':'L':'E':s -> returnP ('\DLE',s,4) - 'D':'C':'1':s -> returnP ('\DC1',s,4) - 'D':'C':'2':s -> returnP ('\DC2',s,4) - 'D':'C':'3':s -> returnP ('\DC3',s,4) - 'D':'C':'4':s -> returnP ('\DC4',s,4) - 'N':'A':'K':s -> returnP ('\NAK',s,4) - 'S':'Y':'N':s -> returnP ('\SYN',s,4) - 'E':'T':'B':s -> returnP ('\ETB',s,4) - 'C':'A':'N':s -> returnP ('\CAN',s,4) - 'E':'M':s -> returnP ('\EM', s,3) - 'S':'U':'B':s -> returnP ('\SUB',s,4) - 'E':'S':'C':s -> returnP ('\ESC',s,4) - 'F':'S':s -> returnP ('\FS', s,3) - 'G':'S':s -> returnP ('\GS', s,3) - 'R':'S':s -> returnP ('\RS', s,3) - 'U':'S':s -> returnP ('\US', s,3) - 'S':'P':s -> returnP ('\SP', s,3) - 'D':'E':'L':s -> returnP ('\DEL',s,4) - - _ -> parseError "Illegal escape sequence" - - --- Stolen from Hugs's Prelude -parseInteger :: Integer -> String -> Integer -parseInteger radix ds = - foldl1 (\n d -> n * radix + d) (map (toInteger . digitToInt) ds) - --- Production cntrl from section B.2 - -cntrl :: String -> P (Char,String,Int) -cntrl (c:s) | c >= '@' && c <= '_' = returnP (chr (ord c - ord '@'), s,2) -cntrl _ = parseError "Illegal control character" - - -pragma :: (Int -> Int -> FilePath -> Bool -> [Char] -> b) - -> Int -> Int -> FilePath -> Bool -> [Char] -> b -pragma cont y x f bol s0 = - case span (==' ') s0 of - (_, 'L':'I':'N':'E':' ':s) -> parseLinePragma cont y f s - (_, 'l':'i':'n':'e':' ':s) -> parseLinePragma cont y f s - (sp,s) -> nestedComment (\y x -> cont y x f) y (x+length sp) bol s - -parseLinePragma :: (Int -> Int -> FilePath -> Bool -> [Char] -> b) - -> Int -> FilePath -> [Char] -> b -parseLinePragma cont y fname s0 = - cont y' 1 fname' True (drop 1 (dropWhile (/= '\n') s0)) - - where s1 = dropWhite s0 - (lineStr, s2) = span isDigit s1 - y' = case reads lineStr of - ((y',_):_) -> y' - _ -> y - s3 = dropWhite s2 - fnameStr = takeWhile (\c -> c /= '"' && c/='\n') (tail s3) - fname' | null s3 || head s3 /= '"' = fname - -- try and get more sharing of file name strings - | fnameStr == fname = fname - | otherwise = fnameStr - dropWhite = dropWhile (\c -> c == ' ' || c == '\t') - -nestedComment :: (Int -> Int -> Bool -> [Char] -> b) - -> Int -> Int -> Bool -> [Char] -> b -nestedComment cont y x bol s0 = - case s0 of - '-':'}':s -> cont y (x+2) bol s - '{':'-':s -> nestedComment (nestedComment cont) y (x+2) bol s - '\t':s -> nestedComment cont y (nextTab x) bol s - '\n':s -> nestedComment cont (y+1) 1 True s - _:s -> nestedComment cont y (x+1) bol s - [] -> error "Internal error: nestedComment" - -nestedDocComment :: ([Char] -> b) - -> (b -> [Char] -> c -> Int -> Int -> d) - -> [Char] -> c -> Int -> Int -> d -nestedDocComment f0 cont0 s0 loc y0 x0 = go f0 cont0 "" y0 x0 s0 - where - go f cont acc y1 x1 s1 = - case s1 of - '-':'}':s -> cont (f (reverse acc)) s loc y1 (x1+2) - '{':'-':s -> nestedComment (\y x _ s2 -> go f cont acc y x s2) - y1 (x1+2) False s - '\t':s -> go f cont ('\t':acc) y1 (nextTab x1) s - '\n':s -> go f cont ('\n':acc) (y1+1) 1 s - c:s -> go f cont (c:acc) y1 (x1+1) s - [] -> error "Internal error: nestedComment" - -oneLineDocComment :: ([Char] -> a) - -> (a -> [Char] -> b -> c -> d -> e) - -> [Char] -> b -> c -> d -> e -oneLineDocComment f cont s loc y x - = cont (f line) rest loc y x -- continue with the newline char - where (line, rest) = break (== '\n') s - -multiLineDocComment :: Num a => ([Char] -> b) - -> (b -> [Char] -> c -> a -> d -> e) - -> [Char] -> c -> a -> d -> e -multiLineDocComment f cont s loc y x - = cont (f comment) s' loc y' x -- continue with the newline char - where (s', comment, y') = slurpExtraCommentLines s [] y - -slurpExtraCommentLines :: Num a => [Char] -> [[Char]] -> a - -> ([Char], [Char], a) -slurpExtraCommentLines s0 lines0 y - = case rest of - '\n':nextline -> - case dropWhile nonNewlineSpace nextline of - -- stop slurping if we see a string of more than two '-'; - -- strings of dashes are useful as separators but we don't - -- want them in the doc. - '-':'-':c:s | c /= '-' - -> slurpExtraCommentLines (c:s) - ((line++"\n"):lines0) (y+1) - _ -> (rest, finished, y) - _ -> (rest, finished, y) - where - (line, rest) = break (== '\n') s0 - finished = concat (reverse (line:lines0)) - -nonNewlineSpace :: Char -> Bool -nonNewlineSpace c = isSpace c && c /= '\n' -\end{code} |