+ update :: a -> String -> String -> String -> String -> IO String
+
+ --[Keyword]
+ listKeys :: a -> IO [String]
+
+data Markup = Text String
+ | Paragraph
+ | Link String String
+ | Bold [Markup]
+ | Emph [Markup]
+ | Heading Int [Markup]
+ | Url String
+ | Underline [Markup]
+ | Strike [Markup]
+ | Pre String
+ | List [[Markup]]
+
+type Document = [Markup]
+
+wikiParser :: Parser Document
+wikiParser = many1 pMain
+
+pPara :: Parser Markup
+pPara = count 2 pEol >> return (Paragraph)
+
+pLink :: Parser Markup
+pLink = do
+ string "[["
+ (l,d) <- pLinkContent
+ case d of
+ [] -> return (Link l l)
+ _ -> return (Link l d)
+
+pList :: Parser Markup
+pList = do
+ list <- many1 $ try pListItem
+ return (List list)
+
+pListItem :: Parser [Markup]
+pListItem = do
+ many1 pEol
+ char '*'
+ many pOneLine
+
+pHeading :: Parser Markup
+pHeading = do
+ many1 pEol
+ level <- many1 $ char '='
+ char ' '
+ s <- pStopAt (' ':level)
+ return (Heading (length level) s)
+
+pURL :: Parser Markup
+pURL = do
+ proto <- many1 letter
+ string "://"
+ s <- many1 (alphaNum <|> oneOf "?.:&-/")
+ return (Url (proto++"://"++s))
+
+pMail :: Parser Markup
+pMail = do
+ user <- many1 (alphaNum <|> oneOf ".-_")
+ char '@'
+ server <- many1 (alphaNum <|> oneOf ".-_")
+ return (Url ("mailto:"++user++"@"++server))
+
+
+pPre :: Parser Markup
+pPre = string "<pre>" >> do
+ s <- pString "</pre>"
+ return (Pre s)
+
+pBold,pEmph,pUnderline,pStrike :: Parser Markup
+pBold = pS "**" (\s -> Bold s)
+pEmph = pS "//" (\s -> Emph s)
+pUnderline = pS "__" (\s -> Underline s)
+pStrike = pS "--" (\s -> Strike s)
+pS s f = string s >> do
+ s <- pStopAt s
+ return (f s)
+
+pOtherChar :: Parser Markup
+pOtherChar = do
+ c <- noneOf "\n\r"
+ return (Text (c:[]))
+
+pText :: Parser Markup
+pText = do
+ t <- many1 alphaNum
+ return (Text t)
+
+pLinkContent :: Parser (String, String)
+pLinkContent = do try (string "]]" >> return ([],[]))
+ <|> try (do
+ string " | "
+ d <- pString "]]"
+ return ([],d))
+ <|> (do
+ c <- anyChar
+ (l,d) <- pLinkContent
+ return (c:l,d))
+
+pStopAt :: String -> Parser Document
+pStopAt xs = pUntil pOneLine xs
+
+pString :: String -> Parser String
+pString xs = pUntil anyChar xs
+
+pEol :: Parser Markup
+pEol = do
+ (string "\n" <|> string "\r\n")
+ return (Text "\r\n")
+
+pUntil :: Parser a -> String -> Parser [a]
+pUntil p xs = manyTill p (try $ string xs)
+
+pMain :: Parser Markup
+pMain = choice [
+ try (pHeading)
+ ,try pList
+ ,try (pPara)
+ ,try(pPre)
+ ,try(pBold)
+ ,try(pEmph)
+ ,try(pUnderline)
+ ,try(pStrike)
+ ,try (pLink)
+ ,try (pURL)
+ ,try (pMail)
+ ,pText
+ ,pOtherChar
+ ,pEol
+ ]
+
+pOneLine = choice [
+ try pBold
+ ,try pEmph
+ ,try pUnderline
+ ,try pStrike
+ ,try pLink
+ ,try pURL
+ ,try pMail
+ ,pText
+ ,pOtherChar
+ ]
+
+newtype PGB = PGB DBService
+
+createPGB :: String -> String -> String -> String -> IO PGB
+createPGB host database user password = let db = createDBService host database "" user password Nothing in return (PGB db)
+
+instance Backend PGB where
+
+ getCurrent (PGB db) key = do
+ result <- selectReturnTuples db $ "SELECT fulltext,timestamp FROM curtexts WHERE keyword="++tov key
+ case result of
+ [text,date]:_ -> return (Just (text,date))
+ _ -> return Nothing
+
+ getList (PGB db) key = do
+ list <- selectReturnTuples db $ "SELECT id, timestamp, author, comment from fulltexts WHERE keyword = "++tov key
+ case list of
+ [[]] -> return []
+ _ -> return $ map (\[id,date,author,comment] -> (id,date,author,comment)) list
+
+ get (PGB db) key id = do
+ list <- selectReturnTuples db $ "SELECT fulltext from fulltexts WHERE id = "++tov id
+ case list of
+ [s]:_ -> return (Just s)
+ _ -> return Nothing
+
+ setCurrent (PGB db) key id = do
+ full <- selectReturnTuples db $ "SELECT keyword FROM fulltexts WHERE keyword="++tov key++" AND id='"++id++"'"
+ cur <- selectReturnTuples db $ "SELECT keyword FROM curtexts WHERE keyword="++tov key
+ case full of
+ [[]] -> do
+ return False
+ _ -> do
+ rows <- case cur of
+ [[]] -> do
+ execute db $ "INSERT INTO current (keyword, id) VALUES ("++tov key++","++tov id++")"
+ _ -> do
+ execute db $ "UPDATE current SET id = "++tov id++" WHERE keyword = "++tov key
+ if rows == 1 then return True
+ else return False
+
+ update (PGB db) key text author comment = do
+ rows <- execute db $ "INSERT INTO fulltexts (keyword,fulltext, author, comment) VALUES ("++tov key++","++tov text++","++tov author++","++tov comment++")"
+ if rows == 0 then return ""
+ else do
+ [[id]] <- selectReturnTuples db $ "SELECT currval('fulltexts_id_seq')"
+ setCurrent (PGB db) key id
+ return id
+
+ listKeys (PGB db) = do
+ list <- selectReturnTuples db $ "SELECT keyword FROM current keyword ORDER BY lower(keyword)"
+ case list of
+ [[]] -> return []
+ _ -> mapM (\[key] -> return key) list
+
+tov :: String -> String
+tov s = '\'':escapeQuery s++"'"
+
+toHtml :: [Markup] -> String
+toHtml [] = []
+toHtml ((Paragraph):xs) = "<p>\n"++toHtml xs
+toHtml ((Text s):xs) = s++toHtml xs
+toHtml ((Link l d):xs) = "<link: "++l++" desc: "++d++">"++toHtml xs
+toHtml ((Bold d):xs) = "<b>"++toHtml d++"</b>"++toHtml xs
+toHtml ((Emph d):xs) = "<em>"++toHtml d++"</em>"++toHtml xs
+toHtml ((Underline d):xs) = "<u>"++toHtml d++"</u>"++toHtml xs
+toHtml ((Strike d):xs) = "<strike>"++toHtml d++"</strike>"++toHtml xs
+toHtml ((Heading n d):xs) = "\n<h"++show n++">"++toHtml d++"</h"++show n++">\n"++toHtml xs
+toHtml ((Url l):xs) = "<link: "++l++">"++toHtml xs
+toHtml ((Pre s):xs) = "<pre>"++s++"</pre>"++toHtml xs
+toHtml ((List l):xs) = "<ul>\n"++(unlines $ map (\s -> "<li>"++toHtml s++"</li>\n") l) ++ "</ul>"++toHtml xs