Added gfm (GitHub-flavored CommonMark) as an input and output format.

This uses bindings to GitHub's fork of cmark, so it should parse gfm exactly as GitHub does (excepting certain postprocessing steps, involving notifications, emojis, etc.). * Added Text.Pandoc.Readers.GFM (exporting readGFM) * Added Text.Pandoc.Writers.GFM (exporting writeGFM) * Added `gfm` as input and output forma Note that tables are currently always rendered as HTML in the writer; this can be improved when CMarkGFM supports tables in output.
author: John MacFarlane <jgm@berkeley.edu> 2017-08-03 10:50:05 -0700
committer: John MacFarlane <jgm@berkeley.edu> 2017-08-07 16:59:31 -0700
commit: 2c81c4c218be757ff2610e3b47548f0642ce5c10 (patch)
tree: 888463a66a9af9bf56f9f635f2b0047080a4dbd3 /src/Text/Pandoc/Writers
parent: 8995281691b56d711c44fb0c5cae2fc675d12eb9 (diff)
download: pandoc-2c81c4c218be757ff2610e3b47548f0642ce5c10.tar.gz
1 files changed, 189 insertions, 0 deletions
diff --git a/src/Text/Pandoc/Writers/GFM.hs b/src/Text/Pandoc/Writers/GFM.hs
new file mode 100644
index 000000000..d9806e2fa
--- /dev/null
+++ b/src/Text/Pandoc/Writers/GFM.hs
@@ -0,0 +1,189 @@
+{-
+Copyright (C) 2015 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.Writers.GFM
+   Copyright   : Copyright (C) 2017 John MacFarlane
+   License     : GNU GPL, version 2 or above
+
+   Maintainer  : John MacFarlane <jgm@berkeley.edu>
+   Stability   : alpha
+   Portability : portable
+
+Conversion of 'Pandoc' documents to CommonMark.
+
+CommonMark:  <http://commonmark.org>
+-}
+module Text.Pandoc.Writers.GFM (writeGFM) where
+
+import CMarkGFM
+import Control.Monad.State.Strict (State, get, modify, runState)
+import Data.Foldable (foldrM)
+import Data.Text (Text)
+import qualified Data.Text as T
+import Text.Pandoc.Class (PandocMonad)
+import Text.Pandoc.Definition
+import Text.Pandoc.Options
+import Text.Pandoc.Shared (isTightList, linesToPara)
+import Text.Pandoc.Templates (renderTemplate')
+import Text.Pandoc.Walk (walkM)
+import Text.Pandoc.Writers.HTML (writeHtml5String)
+import Text.Pandoc.Writers.Shared
+
+-- | Convert Pandoc to GitHub flavored CommonMark.
+writeGFM :: PandocMonad m => WriterOptions -> Pandoc -> m Text
+writeGFM opts (Pandoc meta blocks) = do
+  let (blocks', notes) = runState (walkM processNotes blocks) []
+      notes' = if null notes
+               then []
+               else [OrderedList (1, Decimal, Period) $ reverse notes]
+  main <-  blocksToCommonMark opts (blocks' ++ notes')
+  metadata <- metaToJSON opts
+              (blocksToCommonMark opts)
+              (inlinesToCommonMark opts)
+              meta
+  let context = defField "body" main $ metadata
+  case writerTemplate opts of
+       Nothing  -> return main
+       Just tpl -> renderTemplate' tpl context
+
+processNotes :: Inline -> State [[Block]] Inline
+processNotes (Note bs) = do
+  modify (bs :)
+  notes <- get
+  return $ Str $ "[" ++ show (length notes) ++ "]"
+processNotes x = return x
+
+node :: NodeType -> [Node] -> Node
+node = Node Nothing
+
+blocksToCommonMark :: PandocMonad m => WriterOptions -> [Block] -> m Text
+blocksToCommonMark opts bs = do
+  let cmarkOpts = [optHardBreaks | isEnabled Ext_hard_line_breaks opts]
+      colwidth = if writerWrapText opts == WrapAuto
+                 then Just $ writerColumns opts
+                 else Nothing
+  nodes <- blocksToNodes bs
+  return $
+    nodeToCommonmark cmarkOpts colwidth $
+    node DOCUMENT nodes
+
+inlinesToCommonMark :: PandocMonad m => WriterOptions -> [Inline] -> m Text
+inlinesToCommonMark opts ils = return $
+  nodeToCommonmark cmarkOpts colwidth $ node PARAGRAPH (inlinesToNodes ils)
+   where cmarkOpts = [optHardBreaks | isEnabled Ext_hard_line_breaks opts]
+         colwidth = if writerWrapText opts == WrapAuto
+                       then Just $ writerColumns opts
+                       else Nothing
+
+blocksToNodes :: PandocMonad m => [Block] -> m [Node]
+blocksToNodes = foldrM blockToNodes []
+
+blockToNodes :: PandocMonad m => Block -> [Node] -> m [Node]
+blockToNodes (Plain xs) ns = return (node PARAGRAPH (inlinesToNodes xs) : ns)
+blockToNodes (Para xs) ns = return (node PARAGRAPH (inlinesToNodes xs) : ns)
+blockToNodes (LineBlock lns) ns = blockToNodes (linesToPara lns) ns
+blockToNodes (CodeBlock (_,classes,_) xs) ns = return $
+  (node (CODE_BLOCK (T.pack (unwords classes)) (T.pack xs)) [] : ns)
+blockToNodes (RawBlock fmt xs) ns
+  | fmt == Format "html" = return (node (HTML_BLOCK (T.pack xs)) [] : ns)
+  | otherwise = return (node (CUSTOM_BLOCK (T.pack xs) (T.empty)) [] : ns)
+blockToNodes (BlockQuote bs) ns = do
+  nodes <- blocksToNodes bs
+  return (node BLOCK_QUOTE nodes : ns)
+blockToNodes (BulletList items) ns = do
+  nodes <- mapM blocksToNodes items
+  return (node (LIST ListAttributes{
+                   listType = BULLET_LIST,
+                   listDelim = PERIOD_DELIM,
+                   listTight = isTightList items,
+                   listStart = 1 }) (map (node ITEM) nodes) : ns)
+blockToNodes (OrderedList (start, _sty, delim) items) ns = do
+  nodes <- mapM blocksToNodes items
+  return (node (LIST ListAttributes{
+                   listType = ORDERED_LIST,
+                   listDelim = case delim of
+                                 OneParen  -> PAREN_DELIM
+                                 TwoParens -> PAREN_DELIM
+                                 _         -> PERIOD_DELIM,
+                   listTight = isTightList items,
+                   listStart = start }) (map (node ITEM) nodes) : ns)
+blockToNodes HorizontalRule ns = return (node THEMATIC_BREAK [] : ns)
+blockToNodes (Header lev _ ils) ns = return (node (HEADING lev) (inlinesToNodes ils) : ns)
+blockToNodes (Div _ bs) ns = do
+  nodes <- blocksToNodes bs
+  return (nodes ++ ns)
+blockToNodes (DefinitionList items) ns = blockToNodes (BulletList items') ns
+  where items' = map dlToBullet items
+        dlToBullet (term, ((Para xs : ys) : zs))  =
+          Para (term ++ [LineBreak] ++ xs) : ys ++ concat zs
+        dlToBullet (term, ((Plain xs : ys) : zs)) =
+          Plain (term ++ [LineBreak] ++ xs) : ys ++ concat zs
+        dlToBullet (term, xs) =
+          Para term : concat xs
+blockToNodes t@(Table _ _ _ _ _) ns = do
+  s <- writeHtml5String def $! Pandoc nullMeta [t]
+  return (node (HTML_BLOCK s) [] : ns)
+blockToNodes Null ns = return ns
+
+inlinesToNodes :: [Inline] -> [Node]
+inlinesToNodes  = foldr inlineToNodes []
+
+inlineToNodes :: Inline -> [Node] -> [Node]
+inlineToNodes (Str s) = (node (TEXT (T.pack s)) [] :)
+inlineToNodes Space   = (node (TEXT (T.pack " ")) [] :)
+inlineToNodes LineBreak = (node LINEBREAK [] :)
+inlineToNodes SoftBreak = (node SOFTBREAK [] :)
+inlineToNodes (Emph xs) = (node EMPH (inlinesToNodes xs) :)
+inlineToNodes (Strong xs) = (node STRONG (inlinesToNodes xs) :)
+inlineToNodes (Strikeout xs) =
+  ((node (HTML_INLINE (T.pack "<s>")) [] : inlinesToNodes xs ++
+   [node (HTML_INLINE (T.pack "</s>")) []]) ++ )
+inlineToNodes (Superscript xs) =
+  ((node (HTML_INLINE (T.pack "<sup>")) [] : inlinesToNodes xs ++
+   [node (HTML_INLINE (T.pack "</sup>")) []]) ++ )
+inlineToNodes (Subscript xs) =
+  ((node (HTML_INLINE (T.pack "<sub>")) [] : inlinesToNodes xs ++
+   [node (HTML_INLINE (T.pack "</sub>")) []]) ++ )
+inlineToNodes (SmallCaps xs) =
+  ((node (HTML_INLINE (T.pack "<span class=\"smallcaps\">")) []
+    : inlinesToNodes xs ++
+    [node (HTML_INLINE (T.pack "</span>")) []]) ++ )
+inlineToNodes (Link _ ils (url,tit)) =
+  (node (LINK (T.pack url) (T.pack tit)) (inlinesToNodes ils) :)
+inlineToNodes (Image _ ils (url,tit)) =
+  (node (IMAGE (T.pack url) (T.pack tit)) (inlinesToNodes ils) :)
+inlineToNodes (RawInline fmt xs)
+  | fmt == Format "html" = (node (HTML_INLINE (T.pack xs)) [] :)
+  | otherwise = (node (CUSTOM_INLINE (T.pack xs) (T.empty)) [] :)
+inlineToNodes (Quoted qt ils) =
+  ((node (TEXT start) [] : inlinesToNodes ils ++ [node (TEXT end) []]) ++)
+  where (start, end) = case qt of
+                          SingleQuote -> (T.pack "‘", T.pack "’")
+                          DoubleQuote -> (T.pack "“", T.pack "”")
+inlineToNodes (Code _ str) = (node (CODE (T.pack str)) [] :)
+inlineToNodes (Math mt str) =
+  case mt of
+    InlineMath  ->
+      (node (HTML_INLINE (T.pack ("\\(" ++ str ++ "\\)"))) [] :)
+    DisplayMath ->
+      (node (HTML_INLINE (T.pack ("\\[" ++ str ++ "\\]"))) [] :)
+inlineToNodes (Span _ ils) = (inlinesToNodes ils ++)
+inlineToNodes (Cite _ ils) = (inlinesToNodes ils ++)
+inlineToNodes (Note _) = id -- should not occur
+-- we remove Note elements in preprocessing
author	John MacFarlane <jgm@berkeley.edu>	2017-08-03 10:50:05 -0700
committer	John MacFarlane <jgm@berkeley.edu>	2017-08-07 16:59:31 -0700
commit	2c81c4c218be757ff2610e3b47548f0642ce5c10 (patch)
tree	888463a66a9af9bf56f9f635f2b0047080a4dbd3 /src/Text/Pandoc/Writers
parent	8995281691b56d711c44fb0c5cae2fc675d12eb9 (diff)
download	pandoc-2c81c4c218be757ff2610e3b47548f0642ce5c10.tar.gz