- lexer` :: [Char] Int -> LexerOutput
- lexer` [] i = Right []
- lexer` x i = case lex x i of
- (Right t, rest, i) = lexer` rest i >>= \ts.Right [t:ts]
- (Left e, _, _) = Left e
-
-ret:: TokenValue [Char] Int -> (Either String Token, [Char], Int)
-ret tv rest i = (Right (i, tv), rest, i)
-
-err :: String Int -> (Either String Token, [Char], Int)
-err s i = (Left ("Line " +++ toString i +++ ": " +++ s), [], i)
-
-lex :: [Char] -> (Int -> (Either String Token, [Char], Int))
-lex [] = ret EndOfFileToken []
-lex ['/':'/':xs] = lex (dropWhile ((<>) '\n') xs)
-lex ['/':'*':xs] = \i.let (c, r) = span ((<>) ('*','/')) $ zip2 [' ':xs] xs in
- lex (tl $ map snd $ tl $ r) (i + length [x\\(x, _)<-c | x == '\n'])
-lex ['v':'a':'r':xs] = ret VarToken xs
-lex ['V':'o':'i':'d':xs] = ret VoidToken xs
-lex ['r':'e':'t':'u':'r':'n':xs] = ret ReturnToken xs
-lex ['i':'f':xs] = ret IfToken xs
-lex ['e':'l':'s':'e':xs] = ret ElseToken xs
-lex ['w':'h':'i':'l':'e':xs] = ret WhileToken xs
-lex ['T':'r':'u':'e':xs] = ret TrueToken xs
-lex ['F':'a':'l':'s':'e':xs] = ret FalseToken xs
-lex ['I':'n':'t':xs] = ret IntTypeToken xs
-lex ['C':'h':'a':'r':xs] = ret CharTypeToken xs
-lex ['B':'o':'o':'l':xs] = ret BoolTypeToken xs
-lex [':':':':xs] = ret DoubleColonToken xs
-lex ['!':'=':xs] = ret NotEqualToken xs
-lex ['<':'=':xs] = ret LesserEqToken xs
-lex ['>':'=':xs] = ret GreaterEqToken xs
-lex ['=':'=':xs] = ret EqualsToken xs
-lex ['&':'&':xs] = ret AmpersandsToken xs
-lex ['|':'|':xs] = ret PipesToken xs
-lex ['[':']':xs] = ret EmptyListToken xs
-lex ['-':'>':xs] = ret ArrowToken xs
-lex ['\'':x:'\'':xs] = ret (CharToken x) xs
-lex ['\'':'\\':x:'\'':xs] = case get x EscapeMap of
- Just t = ret (CharToken t) xs
- _ = err ("Unknown escape: \\" +++ toString x)
-lex t=:[x:xs] = case get x SingleCharTokens of
- (Just tok) = ret tok xs
- Nothing
- | x == '\n' = \i.lex xs (i+1)
- | isSpace x = lex xs
- | isDigit x = let (v, r) = span isDigit t in
- ret (NumberToken (toInt $ toString v)) r
- | isAlpha x = let (v, r) = span isIdent t in ret (IdentToken v) r
- with isIdent c = isAlphanum c || c == '_'
- | otherwise = err ("Unexpected character: " +++ toString x)
-
-
-derive gEq TokenValue
-
-(===) :: TokenValue Token -> Bool
-(===) (IdentToken _) (_, IdentToken _) = True
-(===) (NumberToken _) (_, NumberToken _) = True
-(===) (CharToken _) (_, CharToken _) = True
-(===) x (_, y) = gEq {|*|} x y
+ 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)