{- BNF Converter: Alex 2.0 Generator Copyright (C) 2004 Author: Peter Gammie 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.CFtoAlex2 -- Copyright : (C)opyright 2003, {aarne,markus,peteg} at cs dot chalmers dot se -- License : GPL (see COPYING for details) -- -- Maintainer : {markus,aarne} at cs dot chalmers dot se -- Stability : alpha -- Portability : Haskell98 -- -- Hacked version of @BNFC.Backend.Haskell.CFtoAlex@ to cope with Alex2. -- ------------------------------------------------------------------- module BNFC.Backend.Haskell.CFtoAlex2 (cf2alex2) where import Data.Char import Data.List (intercalate, intersperse, sort) import AbsBNF import BNFC.CF import BNFC.Options (TokenText(..)) import BNFC.Backend.Haskell.Utils cf2alex2 :: String -> String -> Bool -> TokenText -> CF -> String cf2alex2 name shareMod shareStrings tokenText cf = unlines $ intercalate [""] [ prelude name shareMod shareStrings tokenText, cMacros, rMacros cf, restOfAlex shareMod shareStrings tokenText cf ] prelude :: String -> String -> Bool -> TokenText -> [String] prelude name shareMod shareStrings tokenText = concat [ [ "-- -*- haskell -*-" , "-- This Alex file was machine-generated by the BNF converter" , "{" , "{-# OPTIONS_GHC -fno-warn-incomplete-patterns #-}" , "module " ++ name ++ " where" , "" ] , [ "import " ++ shareMod | shareStrings ] , tokenTextImport tokenText , [ "}" , "" ] ] 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 -> TokenText -> CF -> [String] restOfAlex _ shareStrings tokenText 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 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)", "", "tokenPos (PT (Pn _ l _) _ :_) = \"line \" ++ show l", "tokenPos (Err (Pn _ l _) :_) = \"line \" ++ show l", "tokenPos _ = \"end of file\"", "", "posLineCol (Pn _ l c) = (l,c)", "mkPosToken t@(PT p _) = (posLineCol p, prToken t)", "", "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", 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 = " ++ show (sorted2tree $ zip (sort resws) [1..]), " 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 AlexInput = (Posn, -- current position,", " Char, -- previous 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')", "", "alexGetChar :: AlexInput -> Maybe (Char,AlexInput)", "alexGetChar (p, _, s) =", " case "++stringUncons++" s of", " "++stringNilP++" -> Nothing", " "++stringConsP++" ->", " let p' = alexMove p c", " in p' `seq` Just (c, (p', c, s))", "", "alexInputPrevChar :: AlexInput -> Char", "alexInputPrevChar (p, c, s) = c", "}" ] where (stringType,stringTake,stringUncons,stringPack,stringUnpack,stringNilP,stringConsP) = case tokenText of StringToken -> ("String", "take", "", "id", "id", "[]", "(c:s)" ) ByteStringToken -> ("BS.ByteString", "BS.take", "BS.uncons", "BS.pack", "BS.unpack", "Nothing", "Just (c,s)") TextToken -> ("Data.Text.Text", "Data.Text.take", "Data.Text.uncons", "Data.Text.pack", "Data.Text.unpack", "Nothing", "Just (c,s)") ifC :: TokenCat -> String -> String ifC cat s = if isUsedCat cf (TokenCat 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_" ++ 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 }" resws = reservedWords cf ++ cfgSymbols cf 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 = if isAlphaNum c then [[c]] else ['\\':[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"]