We no longer have a separate readGFM and writeGFM;
instead, we'll use readCommonMark and writeCommonMark
with githubExtensions.
It remains to implement these extensions conditionally.
Closes#3841.
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.
Now these functions return a pair of a reader/writer and an
Extensions, instead of building the extensions into the
reader/writer. The calling code must explicitly set
readerExtensions or writerExtensions using the Extensions
returned.
The point of the change is to make it possible for the
calling code to determine what extensions are being used.
See #3659.
Writer helper functions were defined in the top-level Text.Pandoc
module. These functions are moved to the Writer submodule as to enable
reuse in other submodules.
