[R-pkg-devel] Macros in Rd files.
On 09/11/2017 3:05 PM, Rolf Turner wrote:
On 09/11/17 23:40, Duncan Murdoch wrote:
On 09/11/2017 5:06 AM, Uwe Ligges wrote:
Note the % may be a comment?
Yes, and the body should be written in Rd markup, not R.? Working out
the appropriate number of escapes is painful; I recommend trial and error.
This worked for me:
?\newcommand{\today}{\Sexpr{format(Sys.Date(),"\\\%d/\\\%m/\\\%Y")}}
Now that is a bit more subtle! I don't understand what "written in Rd
markup" really means, and I don't understand the "\Sexpr" construction.
I'd seen it when looking at the example macros in
/usr/local/lib64/R/share/Rd/macros/system.Rd
but I figured if you know nothing about it, don't mess with it.
Is there anywhere that I could read up about writing "in Rd markup"?
Not sure this would be helpful, but there's http://developer.r-project.org/parseRd.pdf The short summary is this: Rd files are a mess. There are several different modes of parsing that apply: at the top level you have Rd code, and in different contexts you may have R code (or something close to it), or verbatim code (just kidding! There are ways to signal you want out). Table 1 in that document says what syntax is expected within what macro. In \newcommand, it says it wants "verbatim" input, but really it's going to interpret that as Rd input, i.e. LaTeX-like. Regret asking yet? Duncan Murdoch
Anyway, thanks for giving me the recipe, which is what I really need. cheers, Rolf