3 import Data.Text (Text)
4 import qualified Data.Text as T
5 import qualified Data.Text.IO as TIO
7 import Data.Attoparsec.Text
8 -- import Data.Attoparsec.Combinator
9 import Control.Applicative
10 -- import Control.Applicative.Combinators
12 import qualified Data.IntMap.Strict as M
13 import Data.IntMap.Strict ((!))
14 import Data.Functor (void)
15 import Prelude hiding (take)
19 data Rule = Letter Char
21 -- | Then3 Rule Rule Rule
30 -- deriving (Show, Eq)
33 type RuleSet = M.IntMap Rule
38 do text <- TIO.readFile "data/advent19b.txt"
40 let (rules, messages) = successfulParse inputP text
41 let messagesT = map T.pack messages
44 print $ part1 rules messagesT
45 print $ part2 rules messagesT
49 do text <- TIO.readFile fname
50 let (rules, messages) = successfulParse inputP text
51 let messagesT = map T.pack messages
52 let Right newRules = parseOnly rulesP "8: 42 | 42 8\n11: 42 31 | 42 11 31"
53 let updatedRules = M.union newRules rules
54 let myParser = (makeParser updatedRules (See 0)) <* endOfInput
55 return (myParser, updatedRules, messagesT)
61 part2 rules messages = countMatches updatedRules messages
62 where Right newRules = parseOnly rulesP "8: 42 | 42 8\n11: 42 31 | 42 11 31"
63 updatedRules = M.union newRules rules
65 countMatches rules messages
68 $ map (parseOnly myParser) messages
69 where myParser = ((makeParser rules (See 0)) <* endOfInput)
74 makeParser :: RuleSet -> Rule -> Parser ()
75 makeParser m (Letter c) = void $ char c
76 makeParser m (Then rs) = mapM_ (makeParser m) rs
77 makeParser m (Or a b) = (makeParser m a) <|> (makeParser m b)
78 makeParser m (See i) = makeParser m (m!i)
83 rulesP = M.fromList <$> ruleP `sepBy` endOfLine
84 ruleP = (,) <$> decimal <* ": " <*> ruleBodyP
85 ruleBodyP = choice [letterRuleP, orRuleP, thenRuleP, seeRuleP]
87 letterRuleP = Letter <$> ("\"" *> anyChar) <* "\""
88 orRuleP = Or <$> thenRuleP <* " | " <*> thenRuleP
89 thenRuleP = Then <$> seeRuleP `sepBy` (string " ")
90 seeRuleP = See <$> decimal
93 inputP = (,) <$> rulesP <* blankLines <*> messagesP
95 messagesP = (many1 letter) `sepBy` endOfLine
97 blankLines = skipMany1 endOfLine
100 -- successfulParse :: Text -> (Integer, [Maybe Integer])
101 successfulParse parser input =
102 case parseOnly parser input of
103 Left _err -> (M.empty, []) -- TIO.putStr $ T.pack $ parseErrorPretty err
104 Right expressions -> expressions