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{-
Copyright (C) 2015-2017 John MacFarlane <jgm@berkeley.edu>
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.CommonMark
Copyright : Copyright (C) 2015-2017 John MacFarlane
License : GNU GPL, version 2 or above
Maintainer : John MacFarlane <jgm@berkeley.edu>
Stability : alpha
Portability : portable
Conversion of CommonMark-formatted plain text to 'Pandoc' document.
CommonMark is a strongly specified variant of Markdown: http://commonmark.org.
-}
module Text.Pandoc.Readers.CommonMark (readCommonMark)
where
import CMarkGFM
import Control.Monad.State
import Data.Char (isAlphaNum, isLetter, isSpace, toLower)
import Data.List (groupBy)
import qualified Data.Map as Map
import Data.Text (Text, unpack)
import Text.Pandoc.Class (PandocMonad)
import Text.Pandoc.Definition
import Text.Pandoc.Emoji (emojis)
import Text.Pandoc.Options
import Text.Pandoc.Shared (stringify)
import Text.Pandoc.Walk (walkM)
-- | Parse a CommonMark formatted string into a 'Pandoc' structure.
readCommonMark :: PandocMonad m => ReaderOptions -> Text -> m Pandoc
readCommonMark opts s = return $
(if enabled Ext_gfm_auto_identifiers opts
then addHeaderIdentifiers
else id) $
nodeToPandoc opts $ commonmarkToNode opts' exts s
where opts' = [ optSmart | enabled Ext_smart opts ]
exts = [ extStrikethrough | enabled Ext_strikeout opts ] ++
[ extTable | enabled Ext_pipe_tables opts ] ++
[ extAutolink | enabled Ext_autolink_bare_uris opts ]
-- | Returns True if the given extension is enabled.
enabled :: Extension -> ReaderOptions -> Bool
enabled ext opts = ext `extensionEnabled` readerExtensions opts
convertEmojis :: String -> String
convertEmojis (':':xs) =
case break (==':') xs of
(ys,':':zs) ->
case Map.lookup ys emojis of
Just s -> s ++ convertEmojis zs
Nothing -> ':' : ys ++ convertEmojis (':':zs)
_ -> ':':xs
convertEmojis (x:xs) = x : convertEmojis xs
convertEmojis [] = []
addHeaderIdentifiers :: Pandoc -> Pandoc
addHeaderIdentifiers doc = evalState (walkM addHeaderId doc) mempty
addHeaderId :: Block -> State (Map.Map String Int) Block
addHeaderId (Header lev (_,classes,kvs) ils) = do
idmap <- get
let ident = toIdent ils
ident' <- case Map.lookup ident idmap of
Nothing -> do
put (Map.insert ident 1 idmap)
return ident
Just i -> do
put (Map.adjust (+ 1) ident idmap)
return (ident ++ "-" ++ show i)
return $ Header lev (ident',classes,kvs) ils
addHeaderId x = return x
toIdent :: [Inline] -> String
toIdent = map (\c -> if isSpace c then '-' else c)
. filter (\c -> isLetter c || isAlphaNum c || isSpace c ||
c == '_' || c == '-')
. map toLower . stringify
nodeToPandoc :: ReaderOptions -> Node -> Pandoc
nodeToPandoc opts (Node _ DOCUMENT nodes) =
Pandoc nullMeta $ foldr (addBlock opts) [] nodes
nodeToPandoc opts n = -- shouldn't happen
Pandoc nullMeta $ foldr (addBlock opts) [] [n]
addBlocks :: ReaderOptions -> [Node] -> [Block]
addBlocks opts = foldr (addBlock opts) []
addBlock :: ReaderOptions -> Node -> [Block] -> [Block]
addBlock opts (Node _ PARAGRAPH nodes) =
(Para (addInlines opts nodes) :)
addBlock _ (Node _ THEMATIC_BREAK _) =
(HorizontalRule :)
addBlock opts (Node _ BLOCK_QUOTE nodes) =
(BlockQuote (addBlocks opts nodes) :)
addBlock opts (Node _ (HTML_BLOCK t) _)
| enabled Ext_raw_html opts = (RawBlock (Format "html") (unpack t) :)
| otherwise = id
-- Note: the cmark parser will never generate CUSTOM_BLOCK,
-- so we don't need to handle it:
addBlock _ (Node _ (CUSTOM_BLOCK _onEnter _onExit) _nodes) =
id
addBlock _ (Node _ (CODE_BLOCK info t) _) =
(CodeBlock ("", take 1 (words (unpack info)), []) (unpack t) :)
addBlock opts (Node _ (HEADING lev) nodes) =
(Header lev ("",[],[]) (addInlines opts nodes) :)
addBlock opts (Node _ (LIST listAttrs) nodes) =
(constructor (map (setTightness . addBlocks opts . children) nodes) :)
where constructor = case listType listAttrs of
BULLET_LIST -> BulletList
ORDERED_LIST -> OrderedList
(start, DefaultStyle, delim)
start = listStart listAttrs
setTightness = if listTight listAttrs
then map paraToPlain
else id
paraToPlain (Para xs) = Plain xs
paraToPlain x = x
delim = case listDelim listAttrs of
PERIOD_DELIM -> Period
PAREN_DELIM -> OneParen
addBlock opts (Node _ (TABLE alignments) nodes) =
(Table [] aligns widths headers rows :)
where aligns = map fromTableCellAlignment alignments
fromTableCellAlignment NoAlignment = AlignDefault
fromTableCellAlignment LeftAligned = AlignLeft
fromTableCellAlignment RightAligned = AlignRight
fromTableCellAlignment CenterAligned = AlignCenter
widths = replicate numcols 0.0
numcols = if null rows'
then 0
else maximum $ map length rows'
rows' = map toRow $ filter isRow nodes
(headers, rows) = case rows' of
(h:rs) -> (h, rs)
[] -> ([], [])
isRow (Node _ TABLE_ROW _) = True
isRow _ = False
isCell (Node _ TABLE_CELL _) = True
isCell _ = False
toRow (Node _ TABLE_ROW ns) = map toCell $ filter isCell ns
toRow (Node _ t _) = error $ "toRow encountered non-row " ++ show t
toCell (Node _ TABLE_CELL []) = []
toCell (Node _ TABLE_CELL (n:ns))
| isBlockNode n = addBlocks opts (n:ns)
| otherwise = [Plain (addInlines opts (n:ns))]
toCell (Node _ t _) = error $ "toCell encountered non-cell " ++ show t
addBlock _ (Node _ TABLE_ROW _) = id -- handled in TABLE
addBlock _ (Node _ TABLE_CELL _) = id -- handled in TABLE
addBlock _ _ = id
isBlockNode :: Node -> Bool
isBlockNode (Node _ nodetype _) =
case nodetype of
DOCUMENT -> True
THEMATIC_BREAK -> True
PARAGRAPH -> True
BLOCK_QUOTE -> True
HTML_BLOCK _ -> True
CUSTOM_BLOCK _ _ -> True
CODE_BLOCK _ _ -> True
HEADING _ -> True
LIST _ -> True
ITEM -> True
TEXT _ -> False
SOFTBREAK -> False
LINEBREAK -> False
HTML_INLINE _ -> False
CUSTOM_INLINE _ _ -> False
CODE _ -> False
EMPH -> False
STRONG -> False
LINK _ _ -> False
IMAGE _ _ -> False
STRIKETHROUGH -> False
TABLE _ -> False
TABLE_ROW -> False
TABLE_CELL -> False
children :: Node -> [Node]
children (Node _ _ ns) = ns
addInlines :: ReaderOptions -> [Node] -> [Inline]
addInlines opts = foldr (addInline opts) []
addInline :: ReaderOptions -> Node -> [Inline] -> [Inline]
addInline opts (Node _ (TEXT t) _) = (map toinl clumps ++)
where raw = unpack t
clumps = groupBy samekind raw
samekind ' ' ' ' = True
samekind ' ' _ = False
samekind _ ' ' = False
samekind _ _ = True
toinl (' ':_) = Space
toinl xs = Str $ if enabled Ext_emoji opts
then convertEmojis xs
else xs
addInline _ (Node _ LINEBREAK _) = (LineBreak :)
addInline opts (Node _ SOFTBREAK _)
| enabled Ext_hard_line_breaks opts = (LineBreak :)
| otherwise = (SoftBreak :)
addInline opts (Node _ (HTML_INLINE t) _)
| enabled Ext_raw_html opts = (RawInline (Format "html") (unpack t) :)
| otherwise = id
-- Note: the cmark parser will never generate CUSTOM_BLOCK,
-- so we don't need to handle it:
addInline _ (Node _ (CUSTOM_INLINE _onEnter _onExit) _nodes) =
id
addInline _ (Node _ (CODE t) _) =
(Code ("",[],[]) (unpack t) :)
addInline opts (Node _ EMPH nodes) =
(Emph (addInlines opts nodes) :)
addInline opts (Node _ STRONG nodes) =
(Strong (addInlines opts nodes) :)
addInline opts (Node _ STRIKETHROUGH nodes) =
(Strikeout (addInlines opts nodes) :)
addInline opts (Node _ (LINK url title) nodes) =
(Link nullAttr (addInlines opts nodes) (unpack url, unpack title) :)
addInline opts (Node _ (IMAGE url title) nodes) =
(Image nullAttr (addInlines opts nodes) (unpack url, unpack title) :)
addInline _ _ = id
|
