Commit 2b51568606736b5e59183699c558500b8186e7cc - apicius

Experimenting with better errors Getty Ritter 8 years ago

2 changed file(s) with 33 addition(s) and 7 deletion(s). Collapse all Expand all

+25

-5

Apicius/Lexer.x less more

37	37	\$ $idchar + { lex (TkJoin . T.strip) }
38	38
39	39	{
40		data Token = Token ~~AlexPosn TkType deriving (Eq, Show)~~
	40	data Token = Token
	41	{ tkPosn :: AlexPosn
	42	, tkType :: TkType
	43	} deriving (Eq, Show)
41	44
42	45	data TkType
43	46	= TkLCurl

55	58	deriving (Eq, Show)
56	59
57	60	data AlexUserState = AlexUserState
58		{ filePath :: FilePath
	61	{ filePath :: FilePath
	62	, lastToken :: Maybe Token
	63	, thisToken :: Maybe Token
59	64	} deriving (Eq, Show)
60	65
61	66	alexInitUserState :: AlexUserState
62		alexInitUserState = AlexUserState "<unknown>"
	67	alexInitUserState = AlexUserState "<unknown>" Nothing Nothing
63	68
64	69	getFilePath :: Alex FilePath
65	70	getFilePath = liftM filePath alexGetUserState
66	71
67	72	setFilePath :: FilePath -> Alex ()
68		setFilePath ~~= alexSetUserState . AlexUserState~~
	73	setFilePath f = do
	74	userState <- alexGetUserState
	75	alexSetUserState userState { filePath = f }
	76
	77	getLastToken :: Alex (Maybe Token)
	78	getLastToken = liftM lastToken alexGetUserState
	79
	80	setLastToken :: Token -> Alex ()
	81	setLastToken t = do
	82	userState <- alexGetUserState
	83	alexSetUserState userState
	84	{ lastToken = thisToken userState
	85	, thisToken = Just t
	86	}
69	87
70	88	alexMonadScan' :: Alex Token
71	89	alexMonadScan' = do

80	98	alexMonadScan'
81	99	AlexToken inp' len action -> do
82	100	alexSetInput inp'
83		action (ignorePendingBytes inp) len
	101	tok <- action (ignorePendingBytes inp) len
	102	setLastToken tok
	103	return tok
84	104
85	105	alexError' :: AlexPosn -> String -> Alex a
86	106	alexError' (AlexPn _ l c) msg = do

-2

Apicius/Parser.y less more

76	76	lexwrap = (alexMonadScan' >>=)
77	77
78	78	happyError :: Token -> Alex a
79		happyError (Token p t) =
80		alexError' p ("parse error at token " ++ show t)
	79	happyError (Token pos this) = do
	80	last <- getLastToken
	81	let msg = case (fmap tkType last, this) of
	82	(Just TkArrow, TkArrow) ->
	83	"Missing a step description in between arrows."
	84	(_, TkSemi) -> "Unexpected semicolon"
	85	(_, _) -> "parse error at token " ++ show this
	86	alexError' pos msg
81	87
82	88	parseFile :: FilePath -> String -> Either String [Recipe]
83	89	parseFile = runAlex' parse