[Rd] NEWS.md support on CRAN

[Duncan Murdoch]

On 02/06/2015 3:40 PM, Jeroen Ooms wrote:
> On Tue, Jun 2, 2015 at 8:42 PM, Duncan Murdoch <murdoch.duncan at gmail.com> wrote:
>> Several of us have been talking about this, and have more or less decided against pandoc for the within-R version.  It is too hard to build, or to include with R, on weird platforms. Something like commonmark is more likely. We'd also like to separate the parse and render steps.
> 
> The commonmark::markdown_xml function gives the parse tree in xml
> format. From there we could use something like xpath to query the
> content for individual news items and such. I think this is a more
> practical way of exposing the syntax tree than deeply nested lists or
> an external pointer to the internal C handle.
> 

I'd rather avoid adding a dependence on the XML package; it's not a base
or recommended package, so most people don't have it.  Base R doesn't
have any XML processing built in.

One nice thing about the commonmark library is that it is
self-contained, so we can add it to R without pulling in a lot of other
stuff.  Using it to translate Markdown to XML loses that.

Duncan Murdoch