Add support for the LineBlock element to writers

The following markup features are used to output the lines of the `LineBlock`
element:

  - AsciiDoc: a `[verse]` block,
  - ConTeXt: text surrounded by `\startlines` and `\endlines`,
  - HTML: `div` with an per-element style setting to interpret the content as
    pre-wrapped,
  - Markdown: line blocks if the `line_blocks` extension is enabled, a simple
    paragraph with hard linebreaks otherwise,
  - Org: VERSE block,
  - RST: a line block, and
  - all other formats: a paragraph, containing hard linebreaks between lines.

Custom lua writers should be updated to use the `LineBlock` element.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/Text/Pandoc/Writers/AsciiDoc.hs b/src/Text/Pandoc/Writers/AsciiDoc.hs
index 0dfbd705e..c7097c368 100644
--- a/src/Text/Pandoc/Writers/AsciiDoc.hs
+++ b/src/Text/Pandoc/Writers/AsciiDoc.hs
@@ -137,6 +137,13 @@ blockToAsciiDoc opts (Para inlines) = do
                then text "\\"
                else empty
   return $ esc <> contents <> blankline
+blockToAsciiDoc opts (LineBlock lns) = do
+  let docify line = if null line
+                    then return blankline
+                    else inlineListToAsciiDoc opts line
+  let joinWithLinefeeds = nowrap . mconcat . intersperse cr
+  contents <- joinWithLinefeeds <$> mapM docify lns
+  return $ "[verse]" $$ text "--" $$ contents $$ text "--" $$ blankline
 blockToAsciiDoc _ (RawBlock f s)
   | f == "asciidoc" = return $ text s
   | otherwise       = return empty
@@ -459,4 +466,3 @@ inlineToAsciiDoc opts (Span (ident,_,_) ils) = do
   let identifier = if (null ident) then empty else ("[[" <> text ident <> "]]")
   contents <- inlineListToAsciiDoc opts ils
   return $ identifier <> contents
-