Merge pull request #1726 from AlexanderS/twiki-parser

TWiki Reader: add new new twiki reader

7 files changed, 941 insertions, 10 deletions

diff --git a/README b/README
index f117ef103..89964bd4a 100644
--- a/README
+++ b/README
@@ -18,10 +18,11 @@ Org-mode], [DocBook], [txt2tags], [EPUB] and [Word docx]; and it can write plain
 [markdown], [reStructuredText], [XHTML], [HTML 5], [LaTeX] (including
 [beamer] slide shows), [ConTeXt], [RTF], [OPML], [DocBook],
 [OpenDocument], [ODT], [Word docx], [GNU Texinfo], [MediaWiki markup],
-[DokuWiki markup], [Haddock markup], [EPUB] (v2 or v3), [FictionBook2],
-[Textile], [groff man] pages, [Emacs Org-Mode], [AsciiDoc], [InDesign ICML],
-and [Slidy], [Slideous], [DZSlides], [reveal.js] or [S5] HTML slide shows.
-It can also produce [PDF] output on systems where LaTeX is installed.
+[DokuWiki markup], [TWiki markup], [Haddock markup], [EPUB] (v2 or v3),
+[FictionBook2], [Textile], [groff man] pages, [Emacs Org-Mode], [AsciiDoc],
+[InDesign ICML], and [Slidy], [Slideous], [DZSlides], [reveal.js] or
+[S5] HTML slide shows. It can also produce [PDF] output on systems where
+LaTeX is installed.
 
 Pandoc's enhanced version of markdown includes syntax for footnotes,
 tables, flexible ordered lists, definition lists, fenced code blocks,
@@ -161,8 +162,8 @@ General options
     `textile` (Textile), `rst` (reStructuredText), `html` (HTML),
     `docbook` (DocBook), `t2t` (txt2tags), `docx` (docx), `epub` (EPUB),
     `opml` (OPML), `org` (Emacs Org-mode), `mediawiki` (MediaWiki markup),
-    `haddock` (Haddock markup), or `latex` (LaTeX).  If `+lhs` is appended
-    to `markdown`, `rst`,
+    `twiki` (TWiki markpu), `haddock` (Haddock markup), or `latex` (LaTeX).
+    If `+lhs` is appended to `markdown`, `rst`,
     `latex`, or `html`, the input will be treated as literate Haskell
     source: see [Literate Haskell support](#literate-haskell-support),
     below. Markdown syntax extensions can be individually enabled or
@@ -253,8 +254,8 @@ Reader options
     to curly quotes, `---` to em-dashes, `--` to en-dashes, and
     `...` to ellipses. Nonbreaking spaces are inserted after certain
     abbreviations, such as "Mr." (Note: This option is significant only when
-    the input format is `markdown`, `markdown_strict`, or `textile`. It
-    is selected automatically when the input format is `textile` or the
+    the input format is `markdown`, `markdown_strict`, `textile` or `twiki`.
+    It is selected automatically when the input format is `textile` or the
     output format is `latex` or `context`, unless `--no-tex-ligatures`
     is used.)
 
@@ -3182,6 +3183,7 @@ Rosenthal.
 [Textile]: http://redcloth.org/textile
 [MediaWiki markup]: http://www.mediawiki.org/wiki/Help:Formatting
 [DokuWiki markup]: https://www.dokuwiki.org/dokuwiki
+[TWiki markup]: http://twiki.org/cgi-bin/view/TWiki/TextFormattingRules
 [Haddock markup]: http://www.haskell.org/haddock/doc/html/ch03s08.html
 [groff man]: http://developer.apple.com/DOCUMENTATION/Darwin/Reference/ManPages/man7/groff_man.7.html
 [Haskell]:  http://www.haskell.org/
diff --git a/pandoc.cabal b/pandoc.cabal
index b9b996c1f..585b388cd 100644
--- a/pandoc.cabal
+++ b/pandoc.cabal
@@ -20,8 +20,8 @@ Description:     Pandoc is a Haskell library for converting from one markup
                  markup, OPML, Emacs Org-Mode, txt2tags and Textile, and it can write
                  markdown, reStructuredText, HTML, LaTeX, ConTeXt, Docbook,
                  OPML, OpenDocument, ODT, Word docx, RTF, MediaWiki, DokuWiki,
-                 Textile, groff man pages, plain text, Emacs Org-Mode, AsciiDoc,
-                 Haddock markup, EPUB (v2 and v3), FictionBook2,
+                 TWiki, Textile, groff man pages, plain text, Emacs Org-Mode,
+                 AsciiDoc, Haddock markup, EPUB (v2 and v3), FictionBook2,
                  InDesign ICML, and several kinds of HTML/javascript
                  slide shows (S5, Slidy, Slideous, DZSlides, reveal.js).
                  .
@@ -182,6 +182,7 @@ Extra-Source-Files:
                  tests/epub/*.epub
                  tests/epub/*.native
                  tests/txt2tags.t2t
+                 tests/twiki-reader.twiki
 
 Source-repository head
   type:          git
@@ -289,6 +290,7 @@ Library
                    Text.Pandoc.Readers.Textile,
                    Text.Pandoc.Readers.Native,
                    Text.Pandoc.Readers.Haddock,
+                   Text.Pandoc.Readers.TWiki,
                    Text.Pandoc.Readers.Docx,
                    Text.Pandoc.Readers.EPUB,
                    Text.Pandoc.Writers.Native,
diff --git a/src/Text/Pandoc.hs b/src/Text/Pandoc.hs
index fd849316b..1f22122ac 100644
--- a/src/Text/Pandoc.hs
+++ b/src/Text/Pandoc.hs
@@ -77,6 +77,7 @@ module Text.Pandoc
                , readHaddock
                , readNative
                , readJSON
+               , readTWiki
                , readTxt2Tags
                , readTxt2TagsNoMacros
                , readEPUB
@@ -133,6 +134,7 @@ import Text.Pandoc.Readers.HTML
 import Text.Pandoc.Readers.Textile
 import Text.Pandoc.Readers.Native
 import Text.Pandoc.Readers.Haddock
+import Text.Pandoc.Readers.TWiki
 import Text.Pandoc.Readers.Docx
 import Text.Pandoc.Readers.Txt2Tags
 import Text.Pandoc.Readers.EPUB
@@ -233,6 +235,7 @@ readers = [ ("native"       , StringReader $ \_ s -> return $ readNative s)
            ,("html"         , mkStringReader readHtml)
            ,("latex"        , mkStringReader readLaTeX)
            ,("haddock"      , mkStringReader readHaddock)
+           ,("twiki"        , mkStringReader readTWiki)
            ,("docx"         , mkBSReader readDocx)
            ,("t2t"          , mkStringReader readTxt2TagsNoMacros)
            ,("epub"         , mkBSReader readEPUB)
diff --git a/src/Text/Pandoc/Readers/TWiki.hs b/src/Text/Pandoc/Readers/TWiki.hs
new file mode 100644
index 000000000..c2325c0ea
--- /dev/null
+++ b/src/Text/Pandoc/Readers/TWiki.hs
@@ -0,0 +1,526 @@
+{-# LANGUAGE RelaxedPolyRec, FlexibleInstances, TypeSynonymInstances #-}
+-- RelaxedPolyRec needed for inlinesBetween on GHC < 7
+{-
+  Copyright (C) 2014 Alexander Sulfrian <alexander.sulfrian@fu-berlin.de>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+-}
+
+{- |
+   Module      : Text.Pandoc.Readers.TWiki
+   Copyright   : Copyright (C) 2014 Alexander Sulfrian
+   License     : GNU GPL, version 2 or above
+
+   Maintainer  : Alexander Sulfrian <alexander.sulfrian@fu-berlin.de>
+   Stability   : alpha
+   Portability : portable
+
+Conversion of twiki text to 'Pandoc' document.
+-}
+module Text.Pandoc.Readers.TWiki ( readTWiki
+                                 , readTWikiWithWarnings
+                                 ) where
+
+import Text.Pandoc.Definition
+import qualified Text.Pandoc.Builder as B
+import Text.Pandoc.Options
+import Text.Pandoc.Parsing hiding (enclosed, macro, nested)
+import Text.Pandoc.Readers.HTML (htmlTag, isCommentTag)
+import Data.Monoid (Monoid, mconcat, mempty)
+import Control.Applicative ((<$>), (<*), (*>), (<$))
+import Control.Monad
+import Text.Printf (printf)
+import Debug.Trace (trace)
+import Text.Pandoc.XML (fromEntities)
+import Data.Maybe (fromMaybe)
+import Text.HTML.TagSoup
+import Data.Char (isAlphaNum)
+import qualified Data.Foldable as F
+
+-- | Read twiki from an input string and return a Pandoc document.
+readTWiki :: ReaderOptions -- ^ Reader options
+          -> String        -- ^ String to parse (assuming @'\n'@ line endings)
+          -> Pandoc
+readTWiki opts s =
+  (readWith parseTWiki) def{ stateOptions = opts } (s ++ "\n\n")
+
+readTWikiWithWarnings :: ReaderOptions -- ^ Reader options
+                      -> String        -- ^ String to parse (assuming @'\n'@ line endings)
+                      -> (Pandoc, [String])
+readTWikiWithWarnings opts s =
+  (readWith parseTWikiWithWarnings) def{ stateOptions = opts } (s ++ "\n\n")
+ where parseTWikiWithWarnings = do
+         doc <- parseTWiki
+         warnings <- stateWarnings <$> getState
+         return (doc, warnings)
+
+type TWParser = Parser [Char] ParserState
+
+--
+-- utility functions
+--
+
+tryMsg :: String -> TWParser a -> TWParser a
+tryMsg msg p = try p <?> msg
+
+skip :: TWParser a -> TWParser ()
+skip parser = parser >> return ()
+
+nested :: TWParser a -> TWParser a
+nested p = do
+  nestlevel <- stateMaxNestingLevel <$>  getState
+  guard $ nestlevel > 0
+  updateState $ \st -> st{ stateMaxNestingLevel = stateMaxNestingLevel st - 1 }
+  res <- p
+  updateState $ \st -> st{ stateMaxNestingLevel = nestlevel }
+  return res
+
+htmlElement :: String -> TWParser (Attr, String)
+htmlElement tag = tryMsg tag $ do
+  (TagOpen _ attr, _) <- htmlTag (~== TagOpen tag [])
+  content <- manyTill anyChar (endtag <|> endofinput)
+  return (htmlAttrToPandoc attr, trim content)
+  where
+    endtag     = skip $ htmlTag (~== TagClose tag)
+    endofinput = lookAhead $ try $ skipMany blankline >> skipSpaces >> eof
+    trim       = dropWhile (=='\n') . reverse . dropWhile (=='\n') . reverse
+
+htmlAttrToPandoc :: [Attribute String] -> Attr
+htmlAttrToPandoc attrs = (ident, classes, keyvals)
+  where
+    ident   = fromMaybe "" $ lookup "id" attrs
+    classes = maybe [] words $ lookup "class" attrs
+    keyvals = [(k,v) | (k,v) <- attrs, k /= "id" && k /= "class"]
+
+parseHtmlContentWithAttrs :: String -> TWParser a -> TWParser (Attr, [a])
+parseHtmlContentWithAttrs tag parser = do
+  (attr, content) <- htmlElement tag
+  parsedContent <- try $ parseContent content
+  return (attr, parsedContent)
+  where
+    parseContent = parseFromString $ nested $ manyTill parser endOfContent
+    endOfContent = try $ skipMany blankline >> skipSpaces >> eof
+
+parseHtmlContent :: String -> TWParser a -> TWParser [a]
+parseHtmlContent tag p = parseHtmlContentWithAttrs tag p >>= return . snd
+
+--
+-- main parser
+--
+
+parseTWiki :: TWParser Pandoc
+parseTWiki = do
+  bs <- mconcat <$> many block
+  spaces
+  eof
+  return $ B.doc bs
+
+
+--
+-- block parsers
+--
+
+block :: TWParser B.Blocks
+block = do
+  tr <- getOption readerTrace
+  pos <- getPosition
+  res <- mempty <$ skipMany1 blankline
+         <|> blockElements
+         <|> para
+  skipMany blankline
+  when tr $
+    trace (printf "line %d: %s" (sourceLine pos)
+           (take 60 $ show $ B.toList res)) (return ())
+  return res
+
+blockElements :: TWParser B.Blocks
+blockElements = choice [ separator
+                       , header
+                       , verbatim
+                       , literal
+                       , list ""
+                       , table
+                       , blockQuote
+                       , noautolink
+                       ]
+
+separator :: TWParser B.Blocks
+separator = tryMsg "separator" $ string "---" >> newline >> return B.horizontalRule
+
+header :: TWParser B.Blocks
+header = tryMsg "header" $ do
+  string "---"
+  level <- many1 (char '+') >>= return . length
+  guard $ level <= 6
+  classes <- option [] $ string "!!" >> return ["unnumbered"]
+  skipSpaces
+  content <- B.trimInlines . mconcat <$> manyTill inline newline
+  attr <- registerHeader ("", classes, []) content
+  return $ B.headerWith attr level $ content
+
+verbatim :: TWParser B.Blocks
+verbatim = (htmlElement "verbatim" <|> htmlElement "pre")
+           >>= return . (uncurry B.codeBlockWith)
+
+literal :: TWParser B.Blocks
+literal = htmlElement "literal" >>= return . rawBlock
+  where
+    format (_, _, kvs)        = fromMaybe "html" $ lookup "format" kvs
+    rawBlock (attrs, content) = B.rawBlock (format attrs) content
+
+list :: String -> TWParser B.Blocks
+list prefix = choice [ bulletList prefix
+                     , orderedList prefix
+                     , definitionList prefix]
+
+definitionList :: String -> TWParser B.Blocks
+definitionList prefix = tryMsg "definitionList" $ do
+  indent <- lookAhead $ string prefix *> (many1 $ string "   ") <* string "$ "
+  elements <- many $ parseDefinitionListItem (prefix ++ concat indent)
+  return $ B.definitionList elements
+  where
+    parseDefinitionListItem :: String -> TWParser (B.Inlines, [B.Blocks])
+    parseDefinitionListItem indent = do
+      string (indent ++ "$ ") >> skipSpaces
+      term <- many1Till inline $ string ": "
+      line <- listItemLine indent $ string "$ "
+      return $ (mconcat term, [line])
+
+bulletList :: String -> TWParser B.Blocks
+bulletList prefix = tryMsg "bulletList" $
+                    parseList prefix (char '*') (char ' ')
+
+orderedList :: String -> TWParser B.Blocks
+orderedList prefix = tryMsg "orderedList" $
+                     parseList prefix (oneOf "1iIaA") (string ". ")
+
+parseList :: Show a => String -> TWParser Char -> TWParser a -> TWParser B.Blocks
+parseList prefix marker delim = do
+  (indent, style) <- lookAhead $ string prefix *> listStyle <* delim
+  blocks <- many $ parseListItem (prefix ++ indent) (char style <* delim)
+  return $ case style of
+    '1' -> B.orderedListWith (1, DefaultStyle, DefaultDelim) blocks
+    'i' -> B.orderedListWith (1, LowerRoman, DefaultDelim) blocks
+    'I' -> B.orderedListWith (1, UpperRoman, DefaultDelim) blocks
+    'a' -> B.orderedListWith (1, LowerAlpha, DefaultDelim) blocks
+    'A' -> B.orderedListWith (1, UpperAlpha, DefaultDelim) blocks
+    _   -> B.bulletList blocks
+  where
+    listStyle = do
+      indent <- many1 $ string "   "
+      style <- marker
+      return (concat indent, style)
+
+parseListItem :: Show a => String -> TWParser a -> TWParser B.Blocks
+parseListItem prefix marker = string prefix >> marker >> listItemLine prefix marker
+
+listItemLine :: Show a => String -> TWParser a -> TWParser B.Blocks
+listItemLine prefix marker = lineContent >>= parseContent >>= return . mconcat
+  where
+    lineContent = do
+      content <- anyLine
+      continuation <- optionMaybe listContinuation
+      return $ filterSpaces content ++ "\n" ++ (maybe "" ("   " ++) continuation)
+    filterSpaces = reverse . dropWhile (== ' ') . reverse
+    listContinuation = notFollowedBy (string prefix >> marker) >>
+                       string "   " >> lineContent
+    parseContent = parseFromString $ many1 $ nestedList <|> parseInline
+    parseInline = many1Till inline (lastNewline <|> newlineBeforeNestedList) >>=
+                  return . B.plain . mconcat
+    nestedList = list prefix
+    lastNewline = try $ char '\n' <* eof
+    newlineBeforeNestedList = try $ char '\n' <* lookAhead nestedList
+
+table :: TWParser B.Blocks
+table = try $ do
+  tableHead <- optionMaybe $ many1Till tableParseHeader newline >>= return . unzip
+  rows <- many1 tableParseRow
+  return $ buildTable mempty rows $ fromMaybe (align rows, columns rows) tableHead
+  where
+    buildTable caption rows (aligns, heads)
+                    = B.table caption aligns heads rows
+    align rows      = replicate (columCount rows) (AlignDefault, 0)
+    columns rows    = replicate (columCount rows) mempty
+    columCount rows = length $ head rows
+
+tableParseHeader :: TWParser ((Alignment, Double), B.Blocks)
+tableParseHeader = try $ do
+  char '|'
+  leftSpaces <- many spaceChar >>= return . length
+  char '*'
+  content <- tableColumnContent (char '*' >> skipSpaces >> char '|')
+  char '*'
+  rightSpaces <- many spaceChar >>= return . length
+  optional tableEndOfRow
+  return (tableAlign leftSpaces rightSpaces, content)
+  where
+    tableAlign left right
+      | left >= 2 && left == right = (AlignCenter, 0)
+      | left > right = (AlignRight, 0)
+      | otherwise = (AlignLeft, 0)
+
+tableParseRow :: TWParser [B.Blocks]
+tableParseRow = many1Till tableParseColumn newline
+
+tableParseColumn :: TWParser B.Blocks
+tableParseColumn = char '|' *> skipSpaces *>
+                   tableColumnContent (skipSpaces >> char '|')
+                   <* skipSpaces <* optional tableEndOfRow
+
+tableEndOfRow :: TWParser Char
+tableEndOfRow = lookAhead (try $ char '|' >> char '\n') >> char '|'
+
+tableColumnContent :: Show a => TWParser a -> TWParser B.Blocks
+tableColumnContent end = manyTill content (lookAhead $ try end) >>= return . B.plain . mconcat
+  where
+    content = continuation <|> inline
+    continuation = try $ char '\\' >> newline >> return mempty
+
+blockQuote :: TWParser B.Blocks
+blockQuote = parseHtmlContent "blockquote" block >>= return . B.blockQuote . mconcat
+
+noautolink :: TWParser B.Blocks
+noautolink = do
+  (_, content) <- htmlElement "noautolink"
+  st <- getState
+  setState $ st{ stateAllowLinks = False }
+  blocks <- try $ parseContent content
+  setState $ st{ stateAllowLinks = True }
+  return $ mconcat blocks
+  where
+    parseContent      = parseFromString $ many $ block
+
+para :: TWParser B.Blocks
+para = many1Till inline endOfParaElement >>= return . result . mconcat
+ where
+   endOfParaElement = lookAhead $ endOfInput <|> endOfPara <|> newBlockElement
+   endOfInput       = try $ skipMany blankline >> skipSpaces >> eof
+   endOfPara        = try $ blankline >> skipMany1 blankline
+   newBlockElement  = try $ blankline >> skip blockElements
+   result content   = if F.all (==Space) content
+                      then mempty
+                      else B.para $ B.trimInlines content
+
+
+--
+-- inline parsers
+--
+
+inline :: TWParser B.Inlines
+inline = choice [ whitespace
+                , br
+                , macro
+                , strong
+                , strongHtml
+                , strongAndEmph
+                , emph
+                , emphHtml
+                , boldCode
+                , smart
+                , link
+                , htmlComment
+                , code
+                , codeHtml
+                , nop
+                , autoLink
+                , str
+                , symbol
+                ] <?> "inline"
+
+whitespace :: TWParser B.Inlines
+whitespace = (lb <|> regsp) >>= return
+  where lb = try $ skipMany spaceChar >> linebreak >> return B.space
+        regsp = try $ skipMany1 spaceChar >> return B.space
+
+br :: TWParser B.Inlines
+br = try $ string "%BR%" >> return B.linebreak
+
+linebreak :: TWParser B.Inlines
+linebreak = newline >> notFollowedBy newline >> (lastNewline <|> innerNewline)
+  where lastNewline  = eof >> return mempty
+        innerNewline = return B.space
+
+between :: (Show b, Monoid c) => TWParser a -> TWParser b -> (TWParser b -> TWParser c) -> TWParser c
+between start end p =
+  mconcat <$> try (start >> notFollowedBy whitespace >> many1Till (p end) end)
+
+enclosed :: (Show a, Monoid b) => TWParser a -> (TWParser a -> TWParser b) -> TWParser b
+enclosed sep p = between sep (try $ sep <* endMarker) p
+  where
+    endMarker   = lookAhead $ skip endSpace <|> skip (oneOf ".,!?:)|") <|> eof
+    endSpace    = (spaceChar <|> newline) >> return B.space
+
+macro :: TWParser B.Inlines
+macro = macroWithParameters <|> withoutParameters
+  where
+    withoutParameters = enclosed (char '%') (\_ -> macroName) >>= return . emptySpan
+    emptySpan name = buildSpan name [] mempty
+
+macroWithParameters :: TWParser B.Inlines
+macroWithParameters = try $ do
+  char '%'
+  name <- macroName
+  (content, kvs) <- attributes
+  char '%'
+  return $ buildSpan name kvs $ B.str content
+
+buildSpan :: String -> [(String, String)] -> B.Inlines -> B.Inlines
+buildSpan className kvs = B.spanWith attrs
+  where
+    attrs             = ("", ["twiki-macro", className] ++ additionalClasses, kvsWithoutClasses)
+    additionalClasses = maybe [] words $ lookup "class" kvs
+    kvsWithoutClasses = [(k,v) | (k,v) <- kvs, k /= "class"]
+
+macroName :: TWParser String
+macroName = do
+  first <- letter
+  rest <- many $ alphaNum <|> char '_'
+  return (first:rest)
+
+attributes :: TWParser (String, [(String, String)])
+attributes = char '{' *> spnl *> many (attribute <* spnl) <* char '}' >>=
+             return . foldr (either mkContent mkKvs) ([], [])
+  where
+    spnl                      = skipMany (spaceChar <|> newline)
+    mkContent c  ([], kvs)    = (c, kvs)
+    mkContent c  (rest, kvs)  = (c ++ " " ++ rest, kvs)
+    mkKvs     kv (cont, rest) = (cont, (kv : rest))
+
+attribute :: TWParser (Either String (String, String))
+attribute = withKey <|> withoutKey
+  where
+    withKey = try $ do
+      key <- macroName
+      char '='
+      parseValue False >>= return . (curry Right key)
+    withoutKey = try $ parseValue True >>= return . Left
+    parseValue allowSpaces = (withQuotes <|> withoutQuotes allowSpaces) >>= return . fromEntities
+    withQuotes             = between (char '"') (char '"') (\_ -> count 1 $ noneOf ['"'])
+    withoutQuotes allowSpaces
+      | allowSpaces == True = many1 $ noneOf "}"
+      | otherwise           = many1 $ noneOf " }"
+
+nestedInlines :: Show a => TWParser a -> TWParser B.Inlines
+nestedInlines end = innerSpace <|> nestedInline
+  where
+    innerSpace   = try $ whitespace <* (notFollowedBy end)
+    nestedInline = notFollowedBy whitespace >> nested inline
+
+strong :: TWParser B.Inlines
+strong = try $ enclosed (char '*') nestedInlines >>= return . B.strong
+
+strongHtml :: TWParser B.Inlines
+strongHtml = (parseHtmlContent "strong" inline <|> parseHtmlContent "b" inline)
+             >>= return . B.strong . mconcat
+
+strongAndEmph :: TWParser B.Inlines
+strongAndEmph = try $ enclosed (string "__") nestedInlines >>= return . B.emph . B.strong
+
+emph :: TWParser B.Inlines
+emph = try $ enclosed (char '_') nestedInlines >>= return . B.emph
+
+emphHtml :: TWParser B.Inlines
+emphHtml = (parseHtmlContent "em" inline <|> parseHtmlContent "i" inline)
+           >>= return . B.emph . mconcat
+
+nestedString :: Show a => TWParser a -> TWParser String
+nestedString end = innerSpace <|> (count 1 nonspaceChar)
+  where
+    innerSpace = try $ many1 spaceChar <* notFollowedBy end
+
+boldCode :: TWParser B.Inlines
+boldCode = try $ enclosed (string "==") nestedString >>= return . B.strong . B.code . fromEntities
+
+htmlComment :: TWParser B.Inlines
+htmlComment = htmlTag isCommentTag >> return mempty
+
+code :: TWParser B.Inlines
+code = try $ enclosed (char '=') nestedString >>= return . B.code . fromEntities
+
+codeHtml :: TWParser B.Inlines
+codeHtml = do
+  (attrs, content) <- parseHtmlContentWithAttrs "code" anyChar
+  return $ B.codeWith attrs $ fromEntities content
+
+autoLink :: TWParser B.Inlines
+autoLink = try $ do
+  state <- getState
+  guard $ stateAllowLinks state
+  (text, url) <- parseLink
+  guard $ checkLink (head $ reverse url)
+  return $ makeLink (text, url)
+  where
+    parseLink            = notFollowedBy nop >> (uri <|> emailAddress)
+    makeLink (text, url) = B.link url "" $ B.str text
+    checkLink c
+      | c == '/' = True
+      | otherwise = isAlphaNum c
+
+str :: TWParser B.Inlines
+str = (many1 alphaNum <|> count 1 characterReference) >>= return . B.str
+
+nop :: TWParser B.Inlines
+nop = try $ (skip exclamation <|> skip nopTag) >> followContent
+  where
+    exclamation   = char '!'
+    nopTag        = stringAnyCase "<nop>"
+    followContent = many1 nonspaceChar >>= return . B.str . fromEntities
+
+symbol :: TWParser B.Inlines
+symbol = count 1 nonspaceChar >>= return . B.str
+
+smart :: TWParser B.Inlines
+smart = do
+  getOption readerSmart >>= guard
+  doubleQuoted <|> singleQuoted <|>
+    choice [ apostrophe
+           , dash
+           , ellipses
+           ]
+
+singleQuoted :: TWParser B.Inlines
+singleQuoted = try $ do
+  singleQuoteStart
+  withQuoteContext InSingleQuote $
+    many1Till inline singleQuoteEnd >>=
+    (return . B.singleQuoted . B.trimInlines . mconcat)
+
+doubleQuoted :: TWParser B.Inlines
+doubleQuoted = try $ do
+  doubleQuoteStart
+  contents <- mconcat <$> many (try $ notFollowedBy doubleQuoteEnd >> inline)
+  (withQuoteContext InDoubleQuote $ doubleQuoteEnd >>
+   return (B.doubleQuoted $ B.trimInlines contents))
+   <|> (return $ (B.str "\8220") B.<> contents)
+
+link :: TWParser B.Inlines
+link = try $ do
+  st <- getState
+  guard $ stateAllowLinks st
+  setState $ st{ stateAllowLinks = False }
+  (url, title, content) <- linkText
+  setState $ st{ stateAllowLinks = True }
+  return $ B.link url title content
+
+linkText :: TWParser (String, String, B.Inlines)
+linkText = do
+  string "[["
+  url <- many1Till anyChar (char ']')
+  content <- option [B.str url] linkContent
+  char ']'
+  return (url, "", mconcat content)
+  where
+    linkContent      = (char '[') >> many1Till anyChar (char ']') >>= parseLinkContent
+    parseLinkContent = parseFromString $ many1 inline
diff --git a/tests/Tests/Old.hs b/tests/Tests/Old.hs
index 8a256b761..0f7b33dd1 100644
--- a/tests/Tests/Old.hs
+++ b/tests/Tests/Old.hs
@@ -153,6 +153,9 @@ tests = [ testGroup "markdown"
           , test "formatting" ["-r", "epub", "-w", "native"]
               "epub/formatting.epub" "epub/formatting.native"
           ]
+        , testGroup "twiki"
+          [ test "reader" ["-r", "twiki", "-w", "native", "-s"]
+              "twiki-reader.twiki" "twiki-reader.native" ]
         , testGroup "other writers" $ map (\f -> testGroup f $ writerTests f)
           [ "opendocument" , "context" , "texinfo", "icml"
           , "man" , "plain" , "rtf", "org", "asciidoc"
diff --git a/tests/twiki-reader.native b/tests/twiki-reader.native
new file mode 100644
index 000000000..bde55a378
--- /dev/null
+++ b/tests/twiki-reader.native
@@ -0,0 +1,174 @@
+Pandoc (Meta {unMeta = fromList []})
+[Header 1 ("header",[],[]) [Str "header"]
+,Header 2 ("header-level-two",[],[]) [Str "header",Space,Str "level",Space,Str "two"]
+,Header 3 ("header-level-3",[],[]) [Str "header",Space,Str "level",Space,Str "3"]
+,Header 4 ("header-level-four",[],[]) [Str "header",Space,Emph [Str "level"],Space,Str "four"]
+,Header 5 ("header-level-5",[],[]) [Str "header",Space,Str "level",Space,Str "5"]
+,Header 6 ("header-level-6",[],[]) [Str "header",Space,Str "level",Space,Str "6"]
+,Para [Str "---+++++++",Space,Str "not",Space,Str "a",Space,Str "header"]
+,Para [Str "--++",Space,Str "not",Space,Str "a",Space,Str "header"]
+,Header 1 ("emph-and-strong",[],[]) [Str "emph",Space,Str "and",Space,Str "strong"]
+,Para [Emph [Str "emph"],Space,Strong [Str "strong"]]
+,Para [Emph [Strong [Str "strong",Space,Str "and",Space,Str "emph"]]]
+,Para [Strong [Emph [Str "emph",Space,Str "inside"],Space,Str "strong"]]
+,Para [Strong [Str "strong",Space,Str "with",Space,Emph [Str "emph"]]]
+,Para [Emph [Strong [Str "strong",Space,Str "inside"],Space,Str "emph"]]
+,Header 1 ("horizontal-rule",[],[]) [Str "horizontal",Space,Str "rule"]
+,Para [Str "top"]
+,HorizontalRule
+,Para [Str "bottom"]
+,HorizontalRule
+,Header 1 ("nop",[],[]) [Str "nop"]
+,Para [Str "_not",Space,Str "emph_"]
+,Header 1 ("entities",[],[]) [Str "entities"]
+,Para [Str "hi",Space,Str "&",Space,Str "low"]
+,Para [Str "hi",Space,Str "&",Space,Str "low"]
+,Para [Str "G\246del"]
+,Para [Str "\777\2730"]
+,Header 1 ("comments",[],[]) [Str "comments"]
+,Para [Str "inline",Space,Str "comment"]
+,Para [Str "between",Space,Str "blocks"]
+,Header 1 ("linebreaks",[],[]) [Str "linebreaks"]
+,Para [Str "hi",LineBreak,Str "there"]
+,Para [Str "hi",LineBreak,Space,Str "there"]
+,Header 1 ("inline-code",[],[]) [Str "inline",Space,Str "code"]
+,Para [Code ("",[],[]) "*\8594*",Space,Code ("",[],[]) "typed",Space,Code ("",["haskell"],[]) ">>="]
+,Header 1 ("code-blocks",[],[]) [Str "code",Space,Str "blocks"]
+,CodeBlock ("",[],[]) "case xs of\n     (_:_) -> reverse xs\n     []    -> ['*']"
+,CodeBlock ("",["haskell"],[]) "case xs of\n     (_:_) -> reverse xs\n     []    -> ['*']"
+,Header 1 ("block-quotes",[],[]) [Str "block",Space,Str "quotes"]
+,Para [Str "Regular",Space,Str "paragraph"]
+,BlockQuote
+ [Para [Str "This",Space,Str "is",Space,Str "a",Space,Str "block",Space,Str "quote."]
+ ,Para [Str "With",Space,Str "two",Space,Str "paragraphs."]]
+,Para [Str "Nother",Space,Str "paragraph."]
+,Header 1 ("external-links",[],[]) [Str "external",Space,Str "links"]
+,Para [Link [Emph [Str "Google"],Space,Str "search",Space,Str "engine"] ("http://google.com","")]
+,Para [Link [Str "http://johnmacfarlane.net/pandoc/"] ("http://johnmacfarlane.net/pandoc/","")]
+,Para [Link [Str "http://google.com"] ("http://google.com",""),Space,Link [Str "http://yahoo.com"] ("http://yahoo.com","")]
+,Para [Link [Str "email",Space,Str "me"] ("mailto:info@example.org","")]
+,Para [Str "http://google.com"]
+,Para [Str "http://google.com"]
+,Para [Str "http://google.com"]
+,Para [Str "info@example.org"]
+,Para [Str "info@example.org"]
+,Para [Str "info@example.org"]
+,Header 1 ("lists",[],[]) [Str "lists"]
+,BulletList
+ [[Plain [Str "Start",Space,Str "each",Space,Str "line"]]
+ ,[Plain [Str "with",Space,Str "an",Space,Str "asterisk",Space,Str "(*)."]
+  ,BulletList
+   [[Plain [Str "More",Space,Str "asterisks",Space,Str "gives",Space,Str "deeper"]
+    ,BulletList
+     [[Plain [Str "and",Space,Str "deeper",Space,Str "levels."]]]]]]
+ ,[Plain [Str "Line",Space,Str "breaks",LineBreak,Str "don't",Space,Str "break",Space,Str "levels."]]
+ ,[Plain [Str "Continuations",Space,Str "are",Space,Str "also",Space,Str "possible"]
+  ,BulletList
+   [[Plain [Str "and",Space,Str "do",Space,Str "not",Space,Str "break",Space,Str "the",Space,Str "list",Space,Str "flow"]]]]
+ ,[Plain [Str "Level",Space,Str "one"]]]
+,Para [Str "Any",Space,Str "other",Space,Str "start",Space,Str "ends",Space,Str "the",Space,Str "list."]
+,OrderedList (1,DefaultStyle,DefaultDelim)
+ [[Plain [Str "Start",Space,Str "each",Space,Str "line"]]
+ ,[Plain [Str "with",Space,Str "a",Space,Str "number",Space,Str "(1.)."]
+  ,OrderedList (1,DefaultStyle,DefaultDelim)
+   [[Plain [Str "More",Space,Str "number",Space,Str "signs",Space,Str "gives",Space,Str "deeper"]
+    ,OrderedList (1,DefaultStyle,DefaultDelim)
+     [[Plain [Str "and",Space,Str "deeper"]]
+     ,[Plain [Str "levels."]]]]]]
+ ,[Plain [Str "Line",Space,Str "breaks",LineBreak,Str "don't",Space,Str "break",Space,Str "levels."]]
+ ,[Plain [Str "Blank",Space,Str "lines"]]]
+,OrderedList (1,DefaultStyle,DefaultDelim)
+ [[Plain [Str "end",Space,Str "the",Space,Str "list",Space,Str "and",Space,Str "start",Space,Str "another."]]]
+,Para [Str "Any",Space,Str "other",Space,Str "start",Space,Str "also",Space,Str "ends",Space,Str "the",Space,Str "list."]
+,DefinitionList
+ [([Str "item",Space,Str "1"],
+   [[Plain [Str "definition",Space,Str "1"]]])
+ ,([Str "item",Space,Str "2"],
+   [[Plain [Str "definition",Space,Str "2-1",Space,Str "definition",Space,Str "2-2"]]])
+ ,([Str "item",Space,Emph [Str "3"]],
+   [[Plain [Str "definition",Space,Emph [Str "3"]]]])]
+,OrderedList (1,DefaultStyle,DefaultDelim)
+ [[Plain [Str "one"]]
+ ,[Plain [Str "two"]
+  ,BulletList
+   [[Plain [Str "two",Space,Str "point",Space,Str "one"]]
+   ,[Plain [Str "two",Space,Str "point",Space,Str "two"]]]]
+ ,[Plain [Str "three"]
+  ,DefinitionList
+   [([Str "three",Space,Str "item",Space,Str "one"],
+     [[Plain [Str "three",Space,Str "def",Space,Str "one"]]])]]
+ ,[Plain [Str "four"]
+  ,DefinitionList
+   [([Str "four",Space,Str "def",Space,Str "one"],
+     [[Plain [Str "this",Space,Str "is",Space,Str "a",Space,Str "continuation"]]])]]
+ ,[Plain [Str "five"]
+  ,OrderedList (1,DefaultStyle,DefaultDelim)
+   [[Plain [Str "five",Space,Str "sub",Space,Str "1"]
+    ,OrderedList (1,DefaultStyle,DefaultDelim)
+     [[Plain [Str "five",Space,Str "sub",Space,Str "1",Space,Str "sub",Space,Str "1"]]]]
+   ,[Plain [Str "five",Space,Str "sub",Space,Str "2"]]]]]
+,OrderedList (1,DefaultStyle,DefaultDelim)
+ [[Plain [Str "other"]
+  ,OrderedList (1,UpperRoman,DefaultDelim)
+   [[Plain [Str "list"]]
+   ,[Plain [Str "styles"]]]]
+ ,[Plain [Str "are"]
+  ,OrderedList (1,LowerRoman,DefaultDelim)
+   [[Plain [Str "also"]]
+   ,[Plain [Str "possible"]]]]
+ ,[Plain [Str "all"]
+  ,OrderedList (1,LowerAlpha,DefaultDelim)
+   [[Plain [Str "the"]]
+   ,[Plain [Str "different"]]
+   ,[Plain [Str "styles"]]]]
+ ,[Plain [Str "are"]
+  ,OrderedList (1,UpperAlpha,DefaultDelim)
+   [[Plain [Str "implemented"]]
+   ,[Plain [Str "and"]]
+   ,[Plain [Str "supported"]]]]]
+,Header 1 ("tables",[],[]) [Str "tables"]
+,Table [] [AlignDefault,AlignDefault] [0.0,0.0]
+ [[]
+ ,[]]
+ [[[Plain [Str "Orange"]]
+  ,[Plain [Str "Apple"]]]
+ ,[[Plain [Str "Bread"]]
+  ,[Plain [Str "Pie"]]]
+ ,[[Plain [Str "Butter"]]
+  ,[Plain [Str "Ice",Space,Str "cream"]]]]
+,Table [] [AlignLeft,AlignLeft] [0.0,0.0]
+ [[Plain [Str "Orange"]]
+ ,[Plain [Str "Apple"]]]
+ [[[Plain [Str "Bread"]]
+  ,[Plain [Str "Pie"]]]
+ ,[[Plain [Strong [Str "Butter"]]]
+  ,[Plain [Str "Ice",Space,Str "cream"]]]]
+,Table [] [AlignLeft,AlignLeft] [0.0,0.0]
+ [[Plain [Str "Orange"]]
+ ,[Plain [Str "Apple"]]]
+ [[[Plain [Str "Bread",LineBreak,LineBreak,Str "and",Space,Str "cheese"]]
+  ,[Plain [Str "Pie",LineBreak,LineBreak,Strong [Str "apple"],Space,Str "and",Space,Emph [Str "carrot"]]]]]
+,Table [] [AlignDefault,AlignDefault,AlignDefault] [0.0,0.0,0.0]
+ [[]
+ ,[]
+ ,[]]
+ [[[Plain [Str "Orange"]]
+  ,[Plain [Str "Apple"]]
+  ,[Plain [Str "more"]]]
+ ,[[Plain [Str "Bread"]]
+  ,[Plain [Str "Pie"]]
+  ,[Plain [Str "more"]]]
+ ,[[Plain [Str "Butter"]]
+  ,[Plain [Str "Ice",Space,Str "cream"]]
+  ,[Plain [Str "and",Space,Str "more"]]]]
+,Header 1 ("macros",[],[]) [Str "macros"]
+,Para [Span ("",["twiki-macro","TEST"],[]) []]
+,Para [Span ("",["twiki-macro","TEST"],[]) [Str ""]]
+,Para [Span ("",["twiki-macro","TEST"],[]) [Str "content with spaces"]]
+,Para [Span ("",["twiki-macro","TEST"],[]) [Str "content with spaces"]]
+,Para [Span ("",["twiki-macro","TEST"],[("ARG1","test")]) [Str "content with spaces"]]
+,Para [Span ("",["twiki-macro","TEST"],[]) [Str "content with spaces ARG1=test"]]
+,Para [Span ("",["twiki-macro","TEST"],[("ARG1","test")]) [Str "content with spaces"]]
+,Para [Span ("",["twiki-macro","TEST"],[("ARG1","test"),("ARG2","test2")]) [Str ""]]
+,Para [Span ("",["twiki-macro","TEST"],[("ARG1","test"),("ARG2","test2")]) [Str ""]]
+,Para [Span ("",["twiki-macro","TEST"],[("ARG1","test"),("ARG2","test2")]) [Str "multiline\ndoes also work"]]]
diff --git a/tests/twiki-reader.twiki b/tests/twiki-reader.twiki
new file mode 100644
index 000000000..51828ef80
--- /dev/null
+++ b/tests/twiki-reader.twiki
@@ -0,0 +1,221 @@
+---+ header
+
+---++ header level two
+
+---+++ header level 3
+
+---++++ header _level_ four
+
+---+++++ header level 5
+
+---++++++ header level 6
+
+---+++++++ not a header
+
+ --++ not a header
+
+---+ emph and strong
+
+_emph_ *strong*
+
+__strong and emph__
+
+*<i>emph inside</i> strong*
+
+*strong with <i>emph</i>*
+
+_<b>strong inside</b> emph_
+
+---+ horizontal rule
+
+top
+---
+bottom
+
+---
+
+---+ nop
+
+<nop>_not emph_
+
+---+ entities
+
+hi & low
+
+hi &amp; low
+
+G&ouml;del
+
+&#777;&#xAAA;
+
+---+ comments
+
+inline <!-- secret --> comment
+
+<!-- secret -->
+
+between blocks
+
+ <!-- secret -->
+
+---+ linebreaks
+
+hi%BR%there
+
+hi%BR%
+there
+
+---+ inline code
+
+<code>*→*</code> =typed= <code class="haskell">>>=</code>
+
+---+ code blocks
+
+<verbatim>
+case xs of
+     (_:_) -> reverse xs
+     []    -> ['*']
+</verbatim>
+
+<verbatim class="haskell">
+case xs of
+     (_:_) -> reverse xs
+     []    -> ['*']
+</verbatim>
+
+---+ block quotes
+
+Regular paragraph
+<blockquote>
+This is a block quote.
+
+With two paragraphs.
+</blockquote>
+Nother paragraph.
+
+---+ external links
+
+[[http://google.com][<i>Google</i> search engine]]
+
+http://johnmacfarlane.net/pandoc/
+
+[[http://google.com]] [[http://yahoo.com]]
+
+[[mailto:info@example.org][email me]]
+
+!http://google.com
+
+<nop>http://google.com
+
+<noautolink>
+http://google.com
+</noautolink>
+
+!info@example.org
+
+<nop>info@example.org
+
+<noautolink>
+info@example.org
+</noautolink>
+
+---+ lists
+
+   * Start each line
+   * with an asterisk (*).
+      * More asterisks gives deeper
+         * and deeper levels.
+   * Line breaks%BR%don't break levels.
+   * Continuations
+     are also possible
+      * and do not break the list flow
+   * Level one
+Any other start ends the list.
+
+   1. Start each line
+   1. with a number (1.).
+      1. More number signs gives deeper
+         1. and deeper
+         1. levels.
+   1. Line breaks%BR%don't break levels.
+   1. Blank lines
+
+   1. end the list and start another.
+Any other start also
+ends the list.
+
+   $ item 1: definition 1
+   $ item 2: definition 2-1
+      definition 2-2
+   $ item _3_: definition _3_
+
+   1. one
+   1. two
+      * two point one
+      * two point two
+   1. three
+      $ three item one: three def one
+   1. four
+      $ four def one: this
+         is a continuation
+   1. five
+      1. five sub 1
+         1. five sub 1 sub 1
+      1. five sub 2
+
+   1. other
+      I. list
+      I. styles
+   1. are
+      i. also
+      i. possible
+   1. all
+      a. the
+      a. different
+      a. styles
+   1. are
+      A. implemented
+      A. and
+      A. supported
+
+---+ tables
+
+|Orange|Apple|
+|Bread|Pie|
+|Butter|Ice cream|
+
+|*Orange*|*Apple*|
+|Bread|Pie|
+|*Butter*|Ice cream|
+
+|*Orange*|*Apple*|
+|Bread%BR%%BR%and cheese|Pie%BR%%BR%*apple* and <i>carrot</i>|
+
+| Orange | Apple     | more     |
+| Bread  | Pie       | more     |
+| Butter | Ice cream | and more |
+
+---+ macros
+
+%TEST%
+
+%TEST{}%
+
+%TEST{content with spaces}%
+
+%TEST{"content with spaces"}%
+
+%TEST{"content with spaces" ARG1="test"}%
+
+%TEST{content with spaces ARG1=test}%
+
+%TEST{ARG1=test content with spaces}%
+
+%TEST{ARG1=test ARG2=test2}%
+
+%TEST{ARG1="test" ARG2="test2"}%
+
+%TEST{ARG1="test"
+ARG2="test2"
+multiline
+does also work}%