pre_processor
An optional pre-processor function that receives the
metadata
, input_file
, runtime
, knit_meta
,
files_dir
, and output_dir
and can return additional arguments
to pass to pandoc.
post_processor
An optional post-processor function that receives the
metadata
, input_file
, output_file
, clean
,
and verbose
parmaeters, and can return an alternative
output_file
.