diff options
Diffstat (limited to 'Thue')
-rw-r--r-- | Thue/Parser.hs | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/Thue/Parser.hs b/Thue/Parser.hs new file mode 100644 index 0000000..dd40e23 --- /dev/null +++ b/Thue/Parser.hs @@ -0,0 +1,79 @@ +module Parser ( + ThueProgram(..), + Rule(..), + State, + + parseThue + ) where + +import Text.ParserCombinators.Parsec + + + +data ThueProgram = ThueProgram { thueRules :: [Rule] + , thueInitialState :: State } + deriving (Show) + + +data Rule = Rule { original :: State + , replacement :: State } + deriving (Show) + + +type State = String + + + + +parseThue :: String -> Either ParseError ThueProgram +parseThue = parse thue "error" + + + + +thue = do + rs <- many rule + separatorLine + i <- initialState + eof + return (ThueProgram rs i) + + +rule = do + o <- ruleState + separator + r <- state + eol + return (Rule o r) + + +separatorLine = whiteSpace >> separator >> whiteSpace >> eol +separator = string "::=" + + +initialState = do + s <- state `sepEndBy` eol + return (concat s) + + +ruleState = many ruleStateChar + + +ruleStateChar = noneOf "\n\r:" + <|> try (do { char ':'; notFollowedBy (string ":="); return ':'}) + + +state = many stateChar + + +stateChar = noneOf "\n\r" + + +whiteSpace = many (oneOf "\t ") + + +eol = try (string "\r\n") + <|> try (string "\n\r") + <|> try (string "\r") + <|> try (string "\n") + |