Can't use rename on grouped_df

[hmalmedal]

The function rename doesn't work with grouping.

data_frame(a = 1, b = 2) %>%
  group_by(a) %>%
  rename(c = b)

## Source: local data frame [1 x 2]
## Groups: a
## 
##   a b
## 1 1 2

[hadley]

Yes, you can't currently modify grouping columns

[romainfrancois]

But b is not a grouping column here.

[romainfrancois]

I think it was just an oversight in how rename_vars was called. Can you check @hadley and reopen the issue if my understanding of lazyeval is wrong.

BTW, the internal code for select which is used eventually does know how to handle grouping, i.e.

> res <- data_frame(a = 1, b = 2) %>% group_by(a) %>% rename(c = a)
> str(res)
Classes ‘grouped_df’, ‘tbl_df’, ‘tbl’ and 'data.frame': 1 obs. of  2 variables:
 $ c: num 1
 $ b: num 2
 - attr(*, "vars")=List of 1
  ..$ : symbol c
 - attr(*, "drop")= logi TRUE
 - attr(*, "indices")=List of 1
  ..$ : int 0
 - attr(*, "group_sizes")= int 1
 - attr(*, "biggest_group_size")= int 1
 - attr(*, "labels")='data.frame':  1 obs. of  1 variable:
  ..$ c: num 1
  ..- attr(*, "vars")=List of 1
  .. ..$ : symbol c

[hadley]

Ooops, yes. Thanks @romainfrancois !