implementation module lex
-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
-import Data.Functor
-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 i = let (out, rest) = runParser (many anyT) i in case rest of
- [] = out
- _ = Left "Unexpected input after last token"
-
-//lexer functions
-identT = alpha >>= \a -> many (char '_' <|> alphaNum) >>= \as -> return $ IdentToken [a:as]
-numberT = optional (char '-') >>= \sign -> (some digit) >>= \n -> case sign of
- Nothing -> return $ NumberToken $ 5 //fromString n
- _ -> return $ NumberToken $ -5 //(fromString n) * -1
-charLT = CharToken <$> (char '\'' *> item <* char '\'')
-char2T = item >>= \c1 -> case c1 of
- ':' = char ':' >>| return DoubleColonToken
- '<' = char '=' >>| return LesserEqToken
- '>' = char '=' >>| return GreaterEqToken
- '=' = char '=' >>| return EqualsToken
- '&' = char '&' >>| return AmpersandsToken
- '|' = char '|' >>| return PipesToken
- '-' = char '>' >>| return ArrowToken
- _ = zero
-char1T = item >>= \c1 -> findT c1 charTokenMap
-varT = string (fromString "var") >>| return VarToken
-voidT = string (fromString "Void") >>| return VoidToken
-returnT = string (fromString "return") >>| return ReturnToken
-ifT = string (fromString "if") >>| return IfToken
-elseT = string (fromString "else") >>| return ElseToken
-whileT = string (fromString "while") >>| return WhileToken
-trueT = string (fromString "True") >>| return TrueToken
-falseT = string (fromString "False") >>| return FalseToken
-//note, for the anyToken parser the order matters!
-anyT = char2T <|> char1T <|> varT <|> voidT <|> returnT <|> ifT <|> elseT <|> whileT <|>
- trueT <|> falseT <|> numberT <|> identT <|> charLT
-
-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)
-
-
-
-charTokenMap = [('(', BraceOpenToken)
- ,(')', BraceCloseToken)
- ,('{', CBraceOpenToken)
- ,('}', CBraceCloseToken)
- ,('[', SquareOpenToken)
- ,(']', SquareCloseToken)
- ,(',', CommaToken)
- ,(':', ColonToken)
- ,(';', SColonToken)
- ,('.', DotToken)
- ,('+', PlusToken)
- ,('-', DashToken)
- ,('*', StarToken)
- ,('/', SlashToken)
- ,('%', PercentToken)
- ,('=', AssignmentToken)
- ,('<', LesserToken)
- ,('>', BiggerToken)
- ,('!', ExclamationToken)]
-findT c [] = fail "Unrecognized character"
-findT c [(k,v):xs] = if (c==k) (return v) (findT c xs)
-
-
-// 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 = 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 = 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
-
-alphaNum :: Parser Char
-alphaNum = alpha <|> digit
-
-//matches a given String
-string :: [Char] -> Parser [Char]
-string s = mapM_ char s >>| return s
\ No newline at end of file
+import Data.Either, Data.Maybe, Data.Map, Data.Func
+import StdString
+import StdTuple
+import StdBool
+import StdList
+import StdChar
+
+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), [])
repositories / cc1516.git / blobdiff