1 files changed, 84 insertions, 0 deletions
diff --git a/src/Thue/Parser.hs b/src/Thue/Parser.hs
new file mode 100644
index 0000000..2ee41ae
--- /dev/null
+++ b/src/Thue/Parser.hs
@@ -0,0 +1,84 @@
+module Thue.Parser (
+	ThueProgram(..),
+	ThueRule(..),
+	ThueState,
+
+	parseThue
+	) where
+
+import Control.Applicative( some )
+import Text.ParserCombinators.Parsec
+
+
+
+data ThueProgram = ThueProgram { thueRules :: [ThueRule]
+                               , thueInitialState :: ThueState }
+    deriving (Show, Eq)
+
+
+data ThueRule = ThueRule { original :: ThueState
+                         , replacement :: ThueState }
+    deriving (Show, Eq)
+
+
+type ThueState = 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 (ThueRule o r)
+
+
+separatorLine = whiteSpace >> separator >> whiteSpace >> eol
+separator  =  string "::="
+          <?> "rule separator"
+
+
+initialState = do
+	s <- state `sepEndBy` eol
+	return (concat s)
+
+
+ruleState = some ruleStateChar
+
+
+ruleStateChar  =  noneOf "\n\r:"
+	          <|> try (char ':' >> notFollowedBy (string ":=") >> return ':')
+	          <?> "state character"
+
+
+state = many stateChar
+
+
+stateChar  =  noneOf "\n\r"
+          <?> "state character"
+
+
+whiteSpace = many (oneOf "\t ")
+
+
+eol  =  try (string "\r\n")
+    <|> try (string "\n\r")
+    <|> try (string "\r")
+    <|> try (string "\n")
+    <?> "end of line"
+