按组有条件地总结几个变量

我想按组有条件地总结几个变量。下面的代码可以做到这一点,但是我不知道如果不在summary步骤中指定每个变量和条件,如何做到这一点。

library(tidyverse)

dat <- data.frame(group = c("A", "A", "A", "B", "B", "B"),
                  indicator = c(1, 2, 3, 1, 2, 3),
                  var1 = c(1, 0, 1, 2, 1, 2),
                  var2 = c(1, 0, 1, 1, 2, 1))

# dat
#  group indicator var1 var2
#1     A         1    1    1
#2     A         2    0    0
#3     A         3    1    1
#4     B         1    2    1
#5     B         2    1    2
#6     B         3    2    1

dat %>%
  group_by(group) %>%
  summarise(var1 = sum(var1[indicator==1 | indicator==2]),
            var2 = sum(var2[indicator==1 | indicator==2])) 

# A tibble: 2 x 3
#  group  var1  var2
#* <chr> <dbl> <dbl>
#1     A     1     1
#2     B     3     3