> -----Original Message-----
> From: Esmail Bonakdarian [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, May 13, 2008 8:13 AM
> To: Greg Snow
> Cc: Prof Brian Ripley; [EMAIL PROTECTED]
> Subject: Re: [R] Random number generation
>
> Greg Snow wrote:
> >> -----Original Message-----
[snip]
> > you could always run your R scripts through the C preproccessor and
> > have it strip the block comments for you.
>
> Too much work, call me old school, but I like the computer do
> work for me, rather than the other way around :-)
So, have the computer do the work. Here is a simple function that tells the
computer to do the work:
cppsource <- function(file) {
tmp <- paste(tempfile(), '.R', sep='')
system(paste('cpp',file,tmp))
source(tmp)
unlink(tmp)
}
Now, instead of doing source('myfile.R') do cppsource('myfile.R') and it will
automatically do the preproccing to remove the c-style comments (assuming that
cpp is on your path, etc.). If typing the extra 3 characters is too much work,
then just name it something else.
Or if you just want to strip the comments in R and don't want to use the c
preprocessor then the function:
cssource <- function(file) {
tmp <- readLines(file)
tmp2 <- paste(tmp, collapse='\n')
tmp3 <- gsub('(?s)/\\*.*?\\*/','',tmp2,perl=TRUE)
source(textConnection(tmp3))
}
Will do that (it will not deal with nested comments or some other special
cases, but both the above functions worked for my quick test case).
>
> > Given the complexity of implementing block commenting (even
> deciding on the syntax) and the ease of current work arounds,
> the cost benefit ratio probably puts this very near the
> bottom of the priority list.
>
> I couldn't possibly offer an opinion on that .. I'll happily
> defer to you and the other experts here for this.
I am not really an expert on this. I just remember being bitten when writing C
and trying to comment out a section of code that already had a comment in it.
I would rather have the R core team spending their time on their current
priorities than even get involved in a discussion of whether block comments
should be able to be nested or not.
You now have at least 4 possible work arounds, hopefully one of them is
satifactory,
--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
[EMAIL PROTECTED]
(801) 408-8111
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