Is there a way to delete all comments in a R script using RStudio?

Question

I need to shrink a file to the smallest size possible. However, this file is heavily commented.

If I am right the search and replace function in Rstudio supporting REGEX might be helpful with this endeavor.

I appreciate any help.

Whether or not it's possible with regexes: see e.g. http://stackoverflow.com/questions/2319019/. Anyway, a long story; in short: only parser will save you. — gagolews, May 13 '14 at 12:18
Would you do even better if you saved it as an R binary object? It would have to be a function, rather than a script as such, but you can just wrap it in a `function()` call and job done. Then instead of sourcing, you load the binary and call the function. — Spacedman, May 13 '14 at 13:15
Well, not exactly an "RStudio" answer, but you can run your source thorough [formatR](http://cran.r-project.org/web/packages/formatR/formatR.pdf) and there's an option (in one of the functions) to strip comments (IIRC) — hrbrmstr, May 13 '14 at 15:31
apologies. was on mobile and failed to look at the answers first. — hrbrmstr, May 13 '14 at 17:33

score 20 · Accepted Answer · edited Nov 04 '16 at 23:14

I wouldn't approach this task with regexes. It may work, but only in simple cases. Consider the following /tmp/test.R script:

x <- 1 # a comment
y <- "#######"
z <- "# not a comment \" # not \"" # a # comment # here

f <- # a function
   function(n) {
for (i in seq_len(n))
print(i)} #...

As you see, it is a little bit complicated to state where the comment really starts.

If you don't mind reformatting your code (well, you stated that you want the smallest code possible), try the following:

writeLines(as.character(parse("/tmp/test.R")), "/tmp/out.R")

which will give /tmp/out.R with:

x <- 1
y <- "#######"
z <- "# not a comment \" # not \""
f <- function(n) {
    for (i in seq_len(n)) print(i)
}

Alternatively, use a function from the formatR package:

library(formatR)
tidy_source(source="/tmp/test.R", keep.comment=FALSE)
## x <- 1
## y <- "#######"
## z <- "# not a comment \" # not \""
## f <- function(n) {
##     for (i in seq_len(n)) print(i)
## }

BTW, tidy_source has a blank argument, which might be of your interest. But I can't get it to work with formatR 0.10 + R 3.0.2...

Exactly what I was thinking ! And this should also reduce the number of blanks so it minifies the code :) — digEmAll, May 13 '14 at 12:15

Is there a way to delete all comments in a R script using RStudio?

1 Answers1