Magrittr wrap

[edlee123]

Hi Yihui,

Hope you are well. I added a new feature to address magrittr line wrapping (issues #54, #62). The unit tests run, and I added couple more.

Most of it was writing the function magrittr_wrap_lines in utils.R, and adding it into the tidy_source function

Appreciate any feedback you may have

[yihui]

Thanks! This looks pretty cool, but I probably need to try really hard to find time to review it carefully. Before I do that, I just have a quick question: is this feature safe to character strings that happen to contain the %>%, e.g. x <- "The pipe %>% is great!"?

[edlee123]

Thank you for taking a look, no worries, this is a hobby project for me.

To answer your question, the string example you gave wouldn't wrap. Not because I have the regex to exclude pipes in comments, but because my rule is to wrap if there are two or more pipes.

But if it is like:

x <- "The pipe %>% is %$% great!"

Then it'd wrap like:

x <- "The pipe %>%
 is %$%
 great!"

[Excuse my %$% language! (jk)....]

But you just gave me the thought - what if two or more pipes like %>% or %$% are within a comment or roxygen import? Like:

# Testing two pipes %>% and %$% in a comment block

or #' @importFrom magrittr %>% %$% ?

In these particular cases unfortunately it would still wrap. Right now I have magrittr_wrap_lines after the comment unmasking in tidy_source.. User would have to use selectively. But maybe we could move magrittr_wrap_lines before unmask_source, so it could be more flexible

[yihui]

I just simplified the implementation (it's a hack that you probably don't want to understand :). It doesn't support the special case in your previous implementation: when the expression contains only one pipe, the line is still wrapped. Please let me know if you have objections. Thanks a lot!