{- BNF Converter: Alex 3.0 Generator Copyright (C) 2012 Author: Antti-Juhani Kaijanaho Copyright (C) 2004 Author: Peter Gammie (C)opyright 2003, {aarne,markus,peteg} at cs dot chalmers dot se This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA -} module BNFC.Backend.Haskell.CFtoAlex3 (cf2alex3) where import BNFC.CF import Data.List -- For BNFC.Backend.Haskell.RegToAlex, see below. import AbsBNF import Data.Char cf2alex3 :: String -> String -> String -> Bool -> Bool -> CF -> String cf2alex3 name errMod shareMod shareStrings byteStrings cf = unlines $ intercalate [""] [ prelude name errMod shareMod shareStrings byteStrings, cMacros, rMacros cf, restOfAlex shareMod shareStrings byteStrings cf ] prelude :: String -> String -> String -> Bool -> Bool -> [String] prelude name _ shareMod shareStrings byteStrings = [ "-- -*- haskell -*-", "-- This Alex file was machine-generated by the BNF converter", "{", "{-# OPTIONS -fno-warn-incomplete-patterns #-}", "{-# OPTIONS_GHC -w #-}", "module " ++ name ++ " where", "", -- "import " ++ errMod, if shareStrings then "import " ++ shareMod else "", if byteStrings then "import qualified Data.ByteString.Char8 as BS" else "", "import qualified Data.Bits", "import Data.Word (Word8)", "import Data.Char (ord)", "}", "" ] cMacros :: [String] cMacros = [ "$l = [a-zA-Z\\192 - \\255] # [\\215 \\247] -- isolatin1 letter FIXME", "$c = [A-Z\\192-\\221] # [\\215] -- capital isolatin1 letter FIXME", "$s = [a-z\\222-\\255] # [\\247] -- small isolatin1 letter FIXME", "$d = [0-9] -- digit", "$i = [$l $d _ '] -- identifier character", "$u = [\\0-\\255] -- universal: any character" ] rMacros :: CF -> [String] rMacros cf = let symbs = cfgSymbols cf in (if null symbs then [] else [ "@rsyms = -- symbols and non-identifier-like reserved words", " " ++ unwords (intersperse "|" (map mkEsc symbs)) ]) where mkEsc = unwords . esc esc s = if null a then rest else show a : rest where (a,r) = span isAlphaNum s rest = case r of [] -> [] (c:xs) -> s : esc xs where s = if isPrint c then ['\\',c] else '\\':show (ord c) restOfAlex :: String -> Bool -> Bool -> CF -> [String] restOfAlex _ shareStrings byteStrings cf = [ ":-", lexComments (comments cf), "$white+ ;", pTSpec (cfgSymbols cf), userDefTokenTypes, ident, ifC catString ("\\\" ([$u # [\\\" \\\\ \\n]] | (\\\\ (\\\" | \\\\ | \\' | n | t)))* \\\"" ++ "{ tok (\\p s -> PT p (TL $ share $ unescapeInitTail s)) }"), ifC catChar "\\\' ($u # [\\\' \\\\] | \\\\ [\\\\ \\\' n t]) \\' { tok (\\p s -> PT p (TC $ share s)) }", ifC catInteger "$d+ { tok (\\p s -> PT p (TI $ share s)) }", ifC catDouble "$d+ \\. $d+ (e (\\-)? $d+)? { tok (\\p s -> PT p (TD $ share s)) }", "", "{", "", "tok :: (Posn -> String -> Token) -> (Posn -> String -> Token)", "tok f p s = f p s", "", "share :: "++stringType++" -> "++stringType, "share = " ++ if shareStrings then "shareString" else "id", "", "data Tok =", " TS !"++stringType++" !Int -- reserved words and symbols", " | TL !"++stringType++" -- string literals", " | TI !"++stringType++" -- integer literals", " | TV !"++stringType++" -- identifiers", " | TD !"++stringType++" -- double precision float literals", " | TC !"++stringType++" -- character literals", userDefTokenConstrs, " deriving (Eq,Show,Ord)", "", "data Token =", " PT Posn Tok", " | Err Posn", " deriving (Eq,Show,Ord)", "", "printPosn :: Posn -> String", "printPosn (Pn _ l c) = \"line \" ++ show l ++ \", column \" ++ show c", "", "tokenPos :: [Token] -> String", "tokenPos (t:_) = printPosn (tokenPosn t)", "tokenPos [] = \"end of file\"", "", "tokenPosn :: Token -> Posn", "tokenPosn (PT p _) = p", "tokenPosn (Err p) = p", "", "tokenLineCol :: Token -> (Int, Int)", "tokenLineCol = posLineCol . tokenPosn", "", "posLineCol :: Posn -> (Int, Int)", "posLineCol (Pn _ l c) = (l,c)", "", "mkPosToken :: Token -> ((Int, Int), String)", "mkPosToken t@(PT p _) = (posLineCol p, prToken t)", "", "prToken :: Token -> String", "prToken t = case t of", " PT _ (TS s _) -> s", " PT _ (TL s) -> show s", " PT _ (TI s) -> s", " PT _ (TV s) -> s", " PT _ (TD s) -> s", " PT _ (TC s) -> s", " Err _ -> \"#error\"", userDefTokenPrint, "", "data BTree = N | B "++stringType++" Tok BTree BTree deriving (Show)", "", "eitherResIdent :: ("++stringType++" -> Tok) -> "++stringType++" -> Tok", "eitherResIdent tv s = treeFind resWords", " where", " treeFind N = tv s", " treeFind (B a t left right) | s < a = treeFind left", " | s > a = treeFind right", " | s == a = t", "", "resWords :: BTree", "resWords = " ++ show (sorted2tree $ cfTokens cf), " where b s n = let bs = "++stringPack++" s", " in B bs (TS bs n)", "", "unescapeInitTail :: "++stringType++" -> "++stringType++"", "unescapeInitTail = "++stringPack++" . unesc . tail . "++stringUnpack++" where", " unesc s = case s of", " '\\\\':c:cs | elem c ['\\\"', '\\\\', '\\\''] -> c : unesc cs", " '\\\\':'n':cs -> '\\n' : unesc cs", " '\\\\':'t':cs -> '\\t' : unesc cs", " '\"':[] -> []", " c:cs -> c : unesc cs", " _ -> []", "", "-------------------------------------------------------------------", "-- Alex wrapper code.", "-- A modified \"posn\" wrapper.", "-------------------------------------------------------------------", "", "data Posn = Pn !Int !Int !Int", " deriving (Eq, Show,Ord)", "", "alexStartPos :: Posn", "alexStartPos = Pn 0 1 1", "", "alexMove :: Posn -> Char -> Posn", "alexMove (Pn a l c) '\\t' = Pn (a+1) l (((c+7) `div` 8)*8+1)", "alexMove (Pn a l c) '\\n' = Pn (a+1) (l+1) 1", "alexMove (Pn a l c) _ = Pn (a+1) l (c+1)", "", "type Byte = Word8", "", "type AlexInput = (Posn, -- current position,", " Char, -- previous char", " [Byte], -- pending bytes on the current char", " "++stringType++") -- current input string", "", "tokens :: "++stringType++" -> [Token]", "tokens str = go (alexStartPos, '\\n', [], str)", " where", " go :: AlexInput -> [Token]", " go inp@(pos, _, _, str) =", " case alexScan inp 0 of", " AlexEOF -> []", " AlexError (pos, _, _, _) -> [Err pos]", " AlexSkip inp' len -> go inp'", " AlexToken inp' len act -> act pos ("++stringTake++" len str) : (go inp')", "", "alexGetByte :: AlexInput -> Maybe (Byte,AlexInput)", "alexGetByte (p, c, (b:bs), s) = Just (b, (p, c, bs, s))", "alexGetByte (p, _, [], s) =", " case "++stringUncons++" s of", " "++stringNilP++" -> Nothing", " "++stringConsP++" ->", " let p' = alexMove p c", " (b:bs) = utf8Encode c", " in p' `seq` Just (b, (p', c, bs, s))", "", "alexInputPrevChar :: AlexInput -> Char", "alexInputPrevChar (p, c, bs, s) = c", "", "-- | Encode a Haskell String to a list of Word8 values, in UTF8 format.", "utf8Encode :: Char -> [Word8]", "utf8Encode = map fromIntegral . go . ord", " where", " go oc", " | oc <= 0x7f = [oc]", "", " | oc <= 0x7ff = [ 0xc0 + (oc `Data.Bits.shiftR` 6)", " , 0x80 + oc Data.Bits..&. 0x3f", " ]", "", " | oc <= 0xffff = [ 0xe0 + (oc `Data.Bits.shiftR` 12)", " , 0x80 + ((oc `Data.Bits.shiftR` 6) Data.Bits..&. 0x3f)", " , 0x80 + oc Data.Bits..&. 0x3f", " ]", " | otherwise = [ 0xf0 + (oc `Data.Bits.shiftR` 18)", " , 0x80 + ((oc `Data.Bits.shiftR` 12) Data.Bits..&. 0x3f)", " , 0x80 + ((oc `Data.Bits.shiftR` 6) Data.Bits..&. 0x3f)", " , 0x80 + oc Data.Bits..&. 0x3f", " ]", "}" ] where (stringType,stringTake,stringUncons,stringPack,stringUnpack,stringNilP,stringConsP) | byteStrings = ("BS.ByteString", "BS.take", "BS.uncons", "BS.pack", "BS.unpack", "Nothing", "Just (c,s)") | otherwise = ("String", "take", "", "id", "id", "[]", "(c:s)" ) ifC cat s = if isUsedCat cf cat then s else "" lexComments ([],[]) = [] lexComments (xs,s1:ys) = '\"' : s1 ++ "\"" ++ " [.]* ; -- Toss single line comments\n" ++ lexComments (xs, ys) lexComments (([l1,l2],[r1,r2]):xs,[]) = concat [ '\"':l1:l2:"\" ([$u # \\", -- FIXME quotes or escape? r1:"] | \\", r1:"+ [$u # [\\", r1:" \\", r2:"]])* (\"", r1:"\")+ \"", r2:"\" ;\n", lexComments (xs, []) ] lexComments (_ : xs, []) = lexComments (xs,[]) --- lexComments (xs,(_:ys)) = lexComments (xs,ys) -- tokens consisting of special symbols pTSpec [] = "" pTSpec _ = "@rsyms { tok (\\p s -> PT p (eitherResIdent (TV . share) s)) }" userDefTokenTypes = unlines [printRegAlex exp ++ " { tok (\\p s -> PT p (eitherResIdent (T_" ++ show name ++ " . share) s)) }" | (name,exp) <- tokenPragmas cf] userDefTokenConstrs = unlines [" | T_" ++ name ++ " !"++stringType | name <- tokenNames cf] userDefTokenPrint = unlines [" PT _ (T_" ++ name ++ " s) -> s" | name <- tokenNames cf] ident = "$l $i* { tok (\\p s -> PT p (eitherResIdent (TV . share) s)) }" --ifC "Ident" " ::= ^l ^i* { ident p = PT p . eitherResIdent TV }" data BTree = N | B String Int BTree BTree instance Show BTree where showsPrec _ N = showString "N" showsPrec n (B s k l r) = wrap (showString "b " . shows s . showChar ' '. shows k . showChar ' ' . showsPrec 1 l . showChar ' ' . showsPrec 1 r) where wrap f = if n > 0 then showChar '(' . f . showChar ')' else f sorted2tree :: [(String,Int)] -> BTree sorted2tree [] = N sorted2tree xs = B x n (sorted2tree t1) (sorted2tree t2) where (t1, (x,n) : t2) = splitAt (length xs `div` 2) xs ------------------------------------------------------------------- -- Inlined version of @BNFC.Backend.Haskell.RegToAlex@. -- Syntax has changed... ------------------------------------------------------------------- -- modified from pretty-printer generated by the BNF converter -- the top-level printing method printRegAlex :: Reg -> String printRegAlex = render . prt 0 -- you may want to change render and parenth render :: [String] -> String render = rend 0 where rend :: Int -> [String] -> String rend i ss = case ss of "[" :ts -> cons "[" $ rend i ts "(" :ts -> cons "(" $ rend i ts t : "," :ts -> cons t $ space "," $ rend i ts t : ")" :ts -> cons t $ cons ")" $ rend i ts t : "]" :ts -> cons t $ cons "]" $ rend i ts t :ts -> space t $ rend i ts _ -> "" cons s t = s ++ t space t s = if null s then t else t ++ " " ++ s parenth :: [String] -> [String] parenth ss = ["("] ++ ss ++ [")"] -- the printer class does the job class Print a where prt :: Int -> a -> [String] prtList :: [a] -> [String] prtList = concatMap (prt 0) instance Print a => Print [a] where prt _ = prtList instance Print Char where prt _ c = case c of '\n' -> ["\\n"] '\t' -> ["\\t"] c | isAlphaNum c -> [[c]] c | isPrint c -> ['\\':[c]] c -> ['\\':show (ord c)] prtList = map (concat . prt 0) prPrec :: Int -> Int -> [String] -> [String] prPrec i j = if j prPrec i 2 (prt 2 reg0 ++ prt 3 reg) RAlt reg0 reg -> prPrec i 1 (concat [prt 1 reg0 , ["|"] , prt 2 reg]) RMinus reg0 reg -> prPrec i 1 (concat [prt 2 reg0 , ["#"] , prt 2 reg]) RStar reg -> prPrec i 3 (prt 3 reg ++ ["*"]) RPlus reg -> prPrec i 3 (prt 3 reg ++ ["+"]) ROpt reg -> prPrec i 3 (prt 3 reg ++ ["?"]) REps -> prPrec i 3 ["()"] RChar c -> prPrec i 3 (prt 0 c) RAlts str -> prPrec i 3 (concat [["["],prt 0 str,["]"]]) RSeqs str -> prPrec i 2 (concatMap (prt 0) str) RDigit -> prPrec i 3 ["$d"] RLetter -> prPrec i 3 ["$l"] RUpper -> prPrec i 3 ["$c"] RLower -> prPrec i 3 ["$s"] RAny -> prPrec i 3 ["$u"]