+
module LexCore where
import ParserCoreUtils
-import Ratio
-import Char
+import Panic
+import Data.Char
import Numeric
+isNameChar :: Char -> Bool
isNameChar c = isAlpha c || isDigit c || (c == '_') || (c == '\'')
- || (c == ':') || (c == '$')
+ || (c == '$') || (c == '-') || (c == '.')
+
+isKeywordChar :: Char -> Bool
isKeywordChar c = isAlpha c || (c == '_')
lexer :: (Token -> P a) -> P a
lexer cont ('{':cs) = cont TKobrace cs
lexer cont ('}':cs) = cont TKcbrace cs
lexer cont ('=':cs) = cont TKeq cs
+lexer cont (':':'=':':':cs) = cont TKcoloneqcolon cs
lexer cont (':':':':cs) = cont TKcoloncolon cs
lexer cont ('*':cs) = cont TKstar cs
lexer cont ('.':cs) = cont TKdot cs
lexer cont ('?':cs) = cont TKquestion cs
lexer cont (';':cs) = cont TKsemicolon cs
-- 20060420 GHC spits out constructors with colon in them nowadays. jds
-lexer cont (':':cs) = lexName cont TKcname (':':cs)
+-- 20061103 but it's easier to parse if we split on the colon, and treat them
+-- as several tokens
+lexer cont (':':cs) = cont TKcolon cs
-- 20060420 Likewise does it create identifiers starting with dollar. jds
lexer cont ('$':cs) = lexName cont TKname ('$':cs)
-lexer cont (c:cs) = failP "invalid character" [c]
-
-
+lexer _ (c:_) = failP "invalid character" [c]
+lexChar :: (Token -> String -> Int -> ParseResult a) -> String -> Int
+ -> ParseResult a
lexChar cont ('\\':'x':h1:h0:'\'':cs)
- | isHexEscape [h1,h0] = cont (TKchar (hexToChar h1 h0)) cs
-lexChar cont ('\\':cs) = failP "invalid char character" ('\\':(take 10 cs))
-lexChar cont ('\'':cs) = failP "invalid char character" ['\'']
-lexChar cont ('\"':cs) = failP "invalid char character" ['\"']
-lexChar cont (c:'\'':cs) = cont (TKchar c) cs
-
-
+ | isHexEscape [h1,h0] = cont (TKchar (hexToChar h1 h0)) cs
+lexChar _ ('\\':cs) = failP "invalid char character" ('\\':(take 10 cs))
+lexChar _ ('\'':_) = failP "invalid char character" ['\'']
+lexChar _ ('\"':_) = failP "invalid char character" ['\"']
+lexChar cont (c:'\'':cs) = cont (TKchar c) cs
+lexChar _ cs = panic ("lexChar: " ++ show cs)
+
+lexString :: String -> (Token -> [Char] -> Int -> ParseResult a)
+ -> String -> Int -> ParseResult a
lexString s cont ('\\':'x':h1:h0:cs)
- | isHexEscape [h1,h0] = lexString (s++[hexToChar h1 h0]) cont cs
-lexString s cont ('\\':cs) = failP "invalid string character" ['\\']
-lexString s cont ('\'':cs) = failP "invalid string character" ['\'']
+ | isHexEscape [h1,h0] = lexString (s++[hexToChar h1 h0]) cont cs
+lexString _ _ ('\\':_) = failP "invalid string character" ['\\']
+lexString _ _ ('\'':_) = failP "invalid string character" ['\'']
lexString s cont ('\"':cs) = cont (TKstring s) cs
-lexString s cont (c:cs) = lexString (s++[c]) cont cs
+lexString s cont (c:cs) = lexString (s++[c]) cont cs
+lexString _ _ [] = panic "lexString []"
+isHexEscape :: String -> Bool
isHexEscape = all (\c -> isHexDigit c && (isDigit c || isLower c))
+hexToChar :: Char -> Char -> Char
hexToChar h1 h0 = chr (digitToInt h1 * 16 + digitToInt h0)
-
+lexNum :: (Token -> String -> a) -> String -> a
lexNum cont cs =
case cs of
('-':cs) -> f (-1) cs
| isDigit c -> cont (TKrational (fromInteger sgn * r)) rest'
where ((r,rest'):_) = readFloat (digits ++ ('.':c:rest))
-- When reading a floating-point number, which is
- -- a bit complicated, use the Haskell 98 library function
+ -- a bit complicated, use the standard library function
+ -- "readFloat"
(digits,rest) -> cont (TKinteger (sgn * (read digits))) rest
+lexName :: (a -> String -> b) -> (String -> a) -> String -> b
lexName cont cstr cs = cont (cstr name) rest
where (name,rest) = span isNameChar cs
+lexKeyword :: (Token -> [Char] -> Int -> ParseResult a) -> String -> Int
+ -> ParseResult a
lexKeyword cont cs =
case span isKeywordChar cs of
("module",rest) -> cont TKmodule rest
("cast",rest) -> cont TKcast rest
("note",rest) -> cont TKnote rest
("external",rest) -> cont TKexternal rest
+ ("local",rest) -> cont TKlocal rest
("_",rest) -> cont TKwild rest
_ -> failP "invalid keyword" ('%':cs)