X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=lex.icl;h=9a414cbdcc953575434fb4e1b8985b20e5e788f3;hb=6b3981fb80952fe2c510b6f9b849adb0dff77d2c;hp=d46aaa8a3a61265ffccdcee98c2b2182c11c1be5;hpb=6910d87166dedb7032fd31684e52df3d0b25910e;p=cc1516.git diff --git a/lex.icl b/lex.icl index d46aaa8..9a414cb 100644 --- a/lex.icl +++ b/lex.icl @@ -1,151 +1,120 @@ implementation module lex -import Data.Either -import Data.List +import Control.Monad, Control.Applicative +import Data.Either, Data.Func, Data.Maybe, Data.Functor +from StdFunc import o +import StdBool +import StdList +import StdChar 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" - -//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 = liftM CharToken item -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 -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 - -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 + +from Text import class Text(textSize,concat), instance Text String + +import yard + +lexer :: [Char] -> LexerOutput +lexer r = case runParser (lexProgram 1 1) r of + (Right p, _) = Right p + (Left e, _) = Left e + +lexProgram :: Int Int -> Parser Char [Token] +lexProgram line column = lexToken >>= \t->case t of + LexEOF = pure [] + (LexItemError e) = fail + PositionalError line column ("LexerError: " +++ e) + (LexToken c t) = lexProgram line (column+c) + >>= \rest->pure [{line=line, column=column, token=t}:rest] + LexNL = lexProgram (line+1) 1 + (LexSpace l c) = lexProgram (line+l) (column+c) + +:: LexItem + = LexToken Int TokenValue + | LexSpace Int Int + | LexNL + | LexEOF + | LexItemError String + +lexToken :: Parser Char LexItem +lexToken = + //Comments + lexBlockComment <|> lexComment <|> + //Keyword tokens + lexKw "var" VarToken <|> lexKw "Void" VoidToken <|> + lexKw "return" ReturnToken <|> lexKw "if" IfToken <|> + lexKw "else" ElseToken <|> lexKw "while" WhileToken <|> + lexKw "True" TrueToken <|> lexKw "False" FalseToken <|> + lexKw "Int" IntTypeToken <|> lexKw "Bool" BoolTypeToken <|> + lexKw "Char" CharTypeToken <|> + //Character tokens + lexEscape <|> lexCharacter <|> + //Two char ops tokens + lexWord "::" DoubleColonToken <|> lexWord "!=" NotEqualToken <|> + lexWord "<=" LesserEqToken <|> lexWord ">=" GreaterEqToken <|> + lexWord "==" EqualsToken <|> lexWord "&&" AmpersandsToken <|> + lexWord "||" PipesToken <|> lexWord "[]" EmptyListToken <|> + lexWord "->" ArrowToken <|> + //One char ops tokens + lexWord "(" BraceOpenToken <|> + lexWord ")" BraceCloseToken <|> lexWord "{" CBraceOpenToken <|> + lexWord "}" CBraceCloseToken <|> lexWord "[" SquareOpenToken <|> + lexWord "]" SquareCloseToken <|> lexWord "," CommaToken <|> + lexWord ":" ColonToken <|> lexWord ";" SColonToken <|> + lexWord "." DotToken <|> lexWord "+" PlusToken <|> + lexWord "*" StarToken <|> lexWord "/" SlashToken <|> + lexWord "%" PercentToken <|> lexWord "=" AssignmentToken <|> + lexWord "<" LesserToken <|> lexWord ">" BiggerToken <|> + lexWord "!" ExclamationToken <|> lexWord "-" DashToken <|> + //Number and identifier tokens + lexNumber <|> lexIdentifier <|> + (item '\n' >>| pure LexNL) <|> + (satisfy isSpace >>| (pure $ LexSpace 0 1)) <|> + (eof >>| pure LexEOF) 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 + lexWord :: String TokenValue -> Parser Char LexItem + lexWord s tv = list (fromString s) >>| pure (LexToken (textSize s) tv) + + lexKw :: String TokenValue -> Parser Char LexItem + lexKw kw tv = lexWord kw tv <* check (not o isIdentChar) + + lexUntilNL = top until (eof <|> (item '\n' >>| pure Void)) + + lexComment :: Parser Char LexItem + lexComment = list (fromString "//") >>| lexUntilNL + >>= \chars->pure LexNL + + lexBlockComment :: Parser Char LexItem + lexBlockComment = list (fromString "/*") + >>| (top until (list (fromString "*/"))) + >>= \chars->pure $ widthHeight chars 0 0 + where + widthHeight :: [Char] Int Int -> LexItem + widthHeight [] l c = LexSpace l c + widthHeight ['\n':xs] l _ = widthHeight xs (l+1) 0 + widthHeight [x:xs] l c = widthHeight xs l (c+1) + + lexNumber :: Parser Char LexItem + lexNumber = toString <$> some (satisfy isDigit) + >>= \si->pure $ LexToken (textSize si) (NumberToken $ toInt si) + + lexIdentifier :: Parser Char LexItem + lexIdentifier = toString <$> some (satisfy isIdentChar) + >>= \si->pure $ LexToken (textSize si) (IdentToken si) + + isIdentChar c = isAlphanum c || c == '_' + + lexCharacter :: Parser Char LexItem + lexCharacter = item '\'' *> satisfy ((<>) '\'') <* item '\'' + >>= \char->pure $ LexToken 3 (CharToken char) + + lexEscape :: Parser Char LexItem + lexEscape = item '\'' *> item '\\' *> top <* item '\'' + >>= \char->pure case char of + 'a' = LexToken 4 (CharToken $ toChar 7) + 'b' = LexToken 4 (CharToken '\b') + 'b' = LexToken 4 (CharToken '\b') + 'f' = LexToken 4 (CharToken '\f') + 'n' = LexToken 4 (CharToken '\n') + 'r' = LexToken 4 (CharToken '\t') + 'v' = LexToken 4 (CharToken '\v') + '\'' =LexToken 4 (CharToken '\'') + c = (LexItemError $ "Unknown escape: " +++ toString c)