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Diffstat (limited to 'Lexer.x')
| -rw-r--r-- | Lexer.x | 101 |
1 files changed, 0 insertions, 101 deletions
diff --git a/Lexer.x b/Lexer.x deleted file mode 100644 index 700c69e6..00000000 --- a/Lexer.x +++ /dev/null @@ -1,101 +0,0 @@ -{ -module Lexer where -import Control.Monad.Error -} - -%wrapper "monadUserState" - -$digit = 0-9 -$alpha = [a-zA-Z_] -@reserved = "."|"["|"]"|","|":"|"("|")"|"{"|"}"|"|"|"=="|"+" -@ident = $alpha [$alpha $digit]* -@string = \" ($printable)* \" - - -tokens :- - -<0> $white+ ; -<0> @reserved { tok TRes } -<0> @ident { tok TIdent } -<0> $digit+ { tok $ TInt . read } - - -<0> \" { enterString } -<string> \" { leaveString } -<string> ($printable # [\"\\]) { pushString id } -<string> \\ [\"\\\/] { pushString (drop 1) } -<string> \\ [nrt] { pushString (escape . drop 1) } ---<string> \\ 'u' [0-9a-fA-F]{4} --- { pushString (parseUnicode . drop 2) } - --- @string { \s -> TString $ init $ tail s} - - -{ - -escape :: String -> String -escape "r" = "\r" -escape "n" = "\n" -escape "t" = "\t" - -getState :: Alex AlexState -getState = Alex $ \s -> Right (s, s) - -getUserState :: Alex AlexUserState -getUserState = liftM alex_ust getState - -setUserState :: AlexUserState -> Alex () -setUserState s' = Alex $ \s -> Right (s{alex_ust = s'}, ()) - -alexEOF = return $ Nothing - -enterString input len = do - setUserState [] - alexSetStartCode string - skip input len - -pushString f i@(p, _, s) len = do - buf <- getUserState - setUserState (buf ++ [f $ take len s]) - skip i len - -leaveString input len = do - s <- getUserState - alexSetStartCode 0 - return $ Just $ TString $ concat s - - -tok f (p,_,s) len = return $ Just $ f (take len s) -data Token = TRes String | TString String | TIdent String | TInt Int - -instance Show Token where - show (TRes t) = "token " ++ t - show (TString t) = "string " ++ t - show (TIdent t) = "identifier " ++ t - show (TInt t) = "integer " ++ show t - - -type AlexUserState = [String] - -alexInitUserState = undefined - -wrapError (Alex scanner) = Alex $ \s -> case scanner s of - Left message -> Left (message ++ " at " ++ showpos (alex_pos s)) - where - showpos (AlexPn off line col) = "line " ++ show line ++ ", column " ++ show col - x -> x - -scanner = do - tok <- wrapError alexMonadScan - case tok of - Nothing -> do - s <- getState - case alex_scd s of - 0 -> return [] - string -> alexError "Unterminated string literal" - Just tok -> liftM (tok:) scanner - -runLexer :: String -> Either String [Token] -runLexer input = runAlex input scanner - -}
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