X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=lex.icl;h=0adb20c879a4b3492df770199df3ef302989af9b;hb=f4ee031491f6d753513b03f46a602321569e1114;hp=1475a0efacbe9bf2450bc130e76d2de24bfb8a51;hpb=4b8ac77a88528dd1eeac43fd7a6c2e6ac711d5a9;p=cc1516.git diff --git a/lex.icl b/lex.icl index 1475a0e..0adb20c 100644 --- a/lex.icl +++ b/lex.icl @@ -1,102 +1,72 @@ implementation module lex +import Control.Monad import Data.Either -import Data.List -import StdString -import System.CommandLine -import StdFile -import StdMisc -from StdFunc import id, const import Data.Maybe -import Control.Applicative -import Control.Monad -import Control.Monad.State -from Data.Func import $ - -// Misschien moeten we hier continuation style van maken -instance toString lexerOutput where - toString l = "dit is een lexer output, danwel error\n" - -lexer :: [Char] -> LexerOutput [Token] -lexer _ = Left "Not Implemented" - -Start :: *World -> *World -Start w -# (args, w) = getCommandLine w // We lezen nu nog standaard van stdin -# (out, w) = stdio w -# (toparse, out) = readEntireFile out -# out = out <<< toString (lexer toparse) -# (b, w) = fclose out w -| not b = setReturnCode 1 w -= w - where - readEntireFile :: *File -> *([Char], *File) - readEntireFile f - # (b, c, f) = freadc f - | not b = ([], f) - # (cs, f) = readEntireFile f - = ([c:cs], f) - - - -// Clean adaption of Yard, a parsec like parser combinator -:: Parser a = Parser ([Char] -> (LexerOutput a, [Char])) - -runParser :: (Parser a) [Char] -> (LexerOutput a, [Char]) -runParser (Parser p) s = p s - -instance Functor Parser where - fmap f s = liftM f s - -instance Applicative Parser where - pure a = Parser $ \s -> (Right a, s) - (<*>) sf s = ap sf s - -instance Monad Parser where - bind p f = Parser $ \s -> let (out, rest) = runParser p s in case out of - Left e = (Left e, rest) - Right t = runParser (f t) rest - -//gives us some, many and optional -instance Alternative Parser where - empty = zero - (<|>) p1 p2 = parserAlternative p1 p2 -parserAlternative p1 p2 = Parser $ \s -> let (out, rest) = runParser p1 s in case out of - Left e = runParser p2 s - Right t = (Right t, rest) - -//parser that fails with error -fail :: String -> Parser a -fail e = Parser $ \s -> (Left e, s) - -//parser that always fails -zero :: Parser a -zero = fail "Zero parser" - -//matches exactly one Char -item :: Parser Char -item = Parser $ \s -> case s of - [] = (Left "Unexpected empty input", s) - [x:xs] = (Right x, xs) - -//matches any char which satisfies f -satisfy :: (Char -> Bool) -> Parser Char -satisfy f = item >>= (\r -> if (f r) (return r) zero) - -//tries a parser, if it fails returns a default value -optionalDef :: a (Parser a) -> Parser a -optionalDef def p = parserAlternative p (return def) - -//matched given char -char :: Char -> Parser Char -char c = satisfy (\i -> c==i) //I hate that we can't do: satisfy (==c) - -alpha :: Parser Char -alpha = satisfy isAlpha - -digit :: Parser Char -digit = satisfy isDigit - -//matches a given String -string :: [Char] -> Parser [Char] -string s = mapM_ char s >>| return s \ No newline at end of file +import Data.Map +import Data.Func +import StdString +import StdTuple +import StdBool +import StdList +import StdChar +import qualified Text + +SingleCharTokens :: Map Char Token +SingleCharTokens = fromList [ + ('(', BraceOpenToken), (')', BraceCloseToken), ('{', CBraceOpenToken), + ('}', CBraceCloseToken), ('[', SquareOpenToken), (']', SquareCloseToken), + (',', CommaToken), (':', ColonToken), (';', SColonToken), + ('.', DotToken), ('+', PlusToken), ('*', StarToken), ('/', SlashToken), + ('%', PercentToken), ('=', AssignmentToken), ('<', LesserToken), + ('>', BiggerToken), ('!', ExclamationToken)] + +EscapeMap :: Map Char Char +EscapeMap = fromList [('a', toChar 7), ('b', '\b'), ('f', '\f'), ('n', '\n'), + ('r', '\r'), ('t', '\t'), ('v', '\v')] + +lexer :: [Char] -> LexerOutput +lexer [] = Right [] +lexer x = case lex x of + (Right t, rest) = lexer rest >>= \ts.Right [t:ts] + (Left e, _) = Left e + +lex :: [Char] -> (Either String Token, [Char]) +lex [] = (Right EndOfFileToken, []) +lex ['/':'/':xs] = lex $ dropWhile ((<>) '\n') xs +lex ['/':'*':xs] = + lex $ tl $ map snd $ dropWhile ((<>) ('*', '/')) $ zip2 [zero:xs] xs +lex ['v':'a':'r':xs] = (Right VarToken, xs) +lex ['V':'o':'i':'d':xs] = (Right VoidToken, xs) +lex ['r':'e':'t':'u':'r':'n':xs] = (Right ReturnToken, xs) +lex ['i':'f':xs] = (Right IfToken, xs) +lex ['e':'l':'s':'e':xs] = (Right ElseToken, xs) +lex ['w':'h':'i':'l':'e':xs] = (Right WhileToken, xs) +lex ['T':'r':'u':'e':xs] = (Right TrueToken, xs) +lex ['F':'a':'l':'s':'e':xs] = (Right FalseToken, xs) +lex ['I':'n':'t':xs] = (Right IntTypeToken, xs) +lex ['C':'h':'a':'r':xs] = (Right CharTypeToken, xs) +lex ['B':'o':'o':'l':xs] = (Right BoolTypeToken, xs) +lex [':':':':xs] = (Right DoubleColonToken, xs) +lex ['!':'=':xs] = (Right NotEqualToken, xs) +lex ['<':'=':xs] = (Right LesserEqToken, xs) +lex ['>':'=':xs] = (Right GreaterEqToken, xs) +lex ['=':'=':xs] = (Right EqualsToken, xs) +lex ['&':'&':xs] = (Right AmpersandsToken, xs) +lex ['|':'|':xs] = (Right PipesToken, xs) +lex ['-':'>':xs] = (Right ArrowToken, xs) +lex ['\'':x:'\'':xs] = (Right (CharToken x), xs) +lex ['\'':'\\':x:'\'':xs] = case get x EscapeMap of + Just t = (Right (CharToken t), xs) + _ = (Left ("Unknown escape: \\" +++ toString x), []) +lex ['-':t=:[x:xs]] +| isDigit x = let (i, r) = span isDigit t in (Right (NumberToken ['-':i]), r) +| otherwise = (Right DashToken, xs) +lex t=:[x:xs] = case get x SingleCharTokens of + (Just tok) = (Right tok, xs) + Nothing + | isSpace x = lex xs + | isDigit x = let (i, r) = span isDigit t in (Right (NumberToken i), r) + | isAlpha x = let (i, r) = span isIdent t in (Right (IdentToken i), r) + with isIdent c = isAlphanum c || c == '_' + | otherwise = (Left ("Unexpected character: " +++ toString x), [])