Do we need enlabel() and entext()?

[lionel-]

See discussion in #300.

[lionel-]

It seems like these should use rlang capture functions in order to support quasiquotation. But if we do so they won't work with forced arguments. Not sure what's best.

[krlmlr]

It would be great to have them, because enquo() and enexpr() don't work e.g. for S3 methods.

[lionel-]

Just added to 0.3.0 milestone so we don't forget.

[krlmlr]

Thanks. I think I'll use my hack for tibble, need to remove it once a better version becomes available in rlang.

[lionel-]

This should probably wait until 0.4.0 when we have figured out #636.

[mjktfw]

This comment will better fit #553 or #300., but since they're closed, I'll post here for anyone searching for similar solution. I'm storing references to large, but not computationally intensive objects/calls as quosures (along with its digest() and .Random.seed), and this obviously fails due to S3 dispatch. The workaround is to dispatch on quoted arguments.

require(tidyverse)
require(rlang)

dd <- tibble()

fn <- function(x) {
  ex <- eval_tidy(enquo(x))
  UseMethod('fn', ex)
}

fn.tbl_df <- function(x) {
  enquo(x)
}

fn(tibble())
#> <quosure>
#> expr: ^tibble()
#> env:  global
fn(dd)
#> <quosure>
#> expr: ^dd
#> env:  global

Created on 2019-02-06 by the reprex package (v0.2.0).

[lionel-]

Interesting, thanks for sharing!

[lionel-]

count_top <- function(df, variable, n = 5) {
  name <- enlabel(variable)
  df %>%
    mutate(temp = fct_lump(fct_infreq({{ variable }}), n = n)) %>%
    count(!!name := temp)
}

mtcars %>% count_top(as.factor(cyl))
#> # A tibble: 3 x 2
#>   `as.factor(cyl)`     n
#>   <fct>            <int>
#> 1 8                   14
#> 2 4                   11
#> 3 6                    7

[lionel-]

Closing this for now.