[Rd] Can example() code stop the example without generating an error?

[Henrik Bengtsson]

Hi,

does anyone know if it is possible to write example code (in Rd
examples) such that one can stop the example without generating an
error?  Example:

code A
if (cond)
  niceStop()
code B

I know this sounds weird, but I would like some of my Rd examples to
run if and only if another package is available or if a certain large
Affymetrix data file is available.  One can put all of the example in
a function and return from the function if the package is not
available, but then all object assigned are lost. My best/cleanest
solution right now is to use break in a dummy for loop. Examples:

for (z in 1) {

code A
if (cond)
  break
code B

}

Other suggestions?  The solution must off course pass R CMD check.

/Henrik

PS. I know example() calls source(), but I'm not sure how R CMD check
does it. DS.