Tokenizer functions implemented

diff --git a/lex.dcl b/lex.dcl
index f256af5..95bd0bd 100644 (file)
--- a/lex.dcl
+++ b/lex.dcl
@@ -4,7 +4,7 @@ import Data.Either
 
 :: Token
        //Value tokens
-       = IdentToken String // Identifier
+       = IdentToken [Char] // Identifier
        | NumberToken Int   // Integer
        | CharToken Char    // Character literal
        //Keyword tokens
@@ -43,6 +43,7 @@ import Data.Either
        | EqualsToken       // ==
        | AmpersandsToken   // &&
        | PipesToken        // ||
+    | ArrowToken        // ->
 
 :: LexerOutput a :== Either String a
 

diff --git a/lex.icl b/lex.icl
index 1475a0e..d46aaa8 100644 (file)
--- a/lex.icl
+++ b/lex.icl
@@ -20,6 +20,30 @@ instance toString lexerOutput where
 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
@@ -39,6 +63,29 @@ Start w
 
 
 
+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]))
 
@@ -60,10 +107,9 @@ instance Monad Parser where
 //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)
+    (<|>) 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
@@ -85,7 +131,7 @@ 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)
+optionalDef def p = p <|> return def
 
 //matched given char
 char :: Char -> Parser Char
@@ -97,6 +143,9 @@ 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