This is needed, if we want to stay compatible with existing markup, even if markdown mode is switched on. Fragile Rd tags (tags that may contain markup that can be picked up by the markdown parser), are replaced by placeholders. After the markdown to Rd conversion is done, the original text is put back in place of the placeholders.
It puts back the protected fragile Rd commands into the text after the markdown parsing.
escape_rd_for_md(text)unescape_rd_for_md(rd_text, esc_text)
For escape_rd_for_md:
A “safe” version of the input text, where
each fragile Rd tag is replaced by a placeholder. The
original text is added as an attribute for each placeholder.
For unescape_rd_for_md: Rd text.
Input text. Potentially contains Rd and/or markdown markup.
The markdown parsed and interpreted text.
The original escaped text from
escape_rd_for_md().
The list of protected Rd tags is in escaped_for_md.
Some Rd macros are treated specially:
For if, markdown is only allowed in the second argument.
For ifelse markdown is allowed in the second and third arguments.
See also roclet-rd.R for the list of tags that
uses the markdown-enabled parser. Some tags, e.g.
@aliases, @backref, etc. only use the
standard Roxygen parser.