Try to break long lines at assignment first before breaking within RHS

[gadenbuie]

In chromote, we had this line

private$event_callback_counts[[domain]] <- private$event_callback_counts[[domain]] - 1

which, when wrapped to 80 characters with air 1.0.0 becomes

private$event_callback_counts[[domain]] <- private$event_callback_counts[[
        domain
      ]] -
        1

but I'd much rather this break at the <- (without me having to introduce that break manually)

private$event_callback_counts[[domain]] <- 
  private$event_callback_counts[[domain]] - 1

[DavisVaughan]

That's tough because you definitely want this to break within the RHS first

foo <- this %>% that() %>% this_other_long_thing() %>% and_this_one_too_as_well()

I agree the current situation isn't great but I'm not sure what the best situation is yet without diving in a bit more.

The line break right after the <- is currently an opt-in feature (through a persistent line break). It won't ever generate one of those line breaks automatically. I don't really love seeing those kinds of line breaks just appear as soon as you hit the line limit, because I greatly prefer the lhs and rhs to at least start on the same line.

[gadenbuie]

One way of expressing my preference is that I prefer line-wrapping strategies that minimize line breaks, with exceptions.

In my original example, I'd much prefer breaking around an entire expression over introducing several breaks. Once internal breaks are required, then I like consistent breaks.

Personally, I'd be okay with your over-long pipe chain example becoming this

foo <- 
  this %>% that() %>% this_other_long_thing() %>% and_this_one_too_as_well()

if you're only 6 characters over the line width constraint. Very often the second line will still not be under, in which case you'd move to an "internal break" on the RHS

foo <- this_is_too_long %>%
  that() %>%
  this_other_long_thing() %>%
  and_this_one_too_as_well()