Function to filter tibble with argument having same name as a column

Question

A petty problem with an obvious solution to rename the parameter of the function. Yet I am interested whether there is a way how I can achieve the following where column name and argument name are the same?

library(dplyr)
d <- data.frame(x = 1:3)

f <- function(x) {
  list(
          ## returns all b/c always true
          d %>% filter(x == x), 

          ## does not work either
          ## any way to tell dplyr to use the parameter x
          d %>% filter(.data$x == x)
       )
}
f(1)

score 3 · Accepted Answer · answered May 29 '20 at 09:25

3

One option could be:

f <- function(x) {
 d %>% 
  filter(x == !!x)
}

answered May 29 '20 at 09:25

tmfmnk

38,881
4
47
67

Ahhh, I knew there's an easy enough answer. Thanks! Need to wait 4 more minutes to accept the answer though ;) – thothal May 29 '20 at 09:29
Wait with it, I assume there will be other interesting solutions :) – tmfmnk May 29 '20 at 09:30

score 1 · Answer 2 · answered May 29 '20 at 09:42

1

You can use {{}}

library(dplyr)
library(rlang)

f1 <- function(df, x) df %>% filter({{x}} == x)
f1(d, 1)

#  x
#1 1

f1(d, 2)
#  x
#1 2

answered May 29 '20 at 09:42

Ronak Shah

377,200
20
156
213

Interesting, where can I read the help on `{{`? – thothal May 29 '20 at 10:16
It is at `?\`{{\`` or this link https://www.tidyverse.org/blog/2019/06/rlang-0-4-0/ – Ronak Shah May 29 '20 at 10:31

Function to filter tibble with argument having same name as a column

2 Answers2