r - 将点中的名称更改为字符

Question

我有一个这样的功能:

my_fun <- function(...,x,y){
  list(...)
}

我希望能够将变量名称或字符串提供给省略号，并在返回之前将所有内容转换为字符。在我的实际情况中，我将通过 do.call(custom_fun,list(...)) 调用自定义函数.

预期输出

我在这里问的是一个函数 my_fun2这将具有以下行为:

my_fun2 <- function(...,x,y){
  MAGIC(list(...))
}

identical(my_fun("a",foo= "b == 3",c("c","d"),bar=c("e","f"),c("g","h")),
          my_fun2("a",foo= b == 3,c("c","d"),bar = c("e",f),c(g,h)))

应该是 TRUE两个术语都返回:

# [[1]]
# [1] "a"
# 
# $foo
# [1] "b == 3"
# 
# [[3]]
# [1] "c" "d"
# 
# $bar
# [1] "e" "f"
# 
# [[5]]
# [1] "g" "h"

我试过的...

my_fun2 <- function(...,x,y){
 lapply(pryr::dots(...),as.character)
}

my_fun2("a",b == 3,c("c","d"),c("e",f),c(g,h))
# [[1]]
# [1] "a"
# 
# [[2]]
# [1] "==" "b"  "3" 
# 
# [[3]]
# [1] "c" "c" "d"
# 
# [[4]]
# [1] "c" "e" "f"
# 
# [[5]]
# [1] "c" "g" "h"

备注

我对表达式、引号、quosures、调用、名称......没有很好的理解，所以我会感谢与案例相关的解释。

我对使用其中一个(或两者!)的解决方案没问题 base ( substitute 、 quote 等)和 dplyr答案( enquo 、 quos 等)

Answer 1

我不骄傲，但这是必须的……

library(dplyr)
library(purrr)
library(pryr)
my_fun2 <- function(...,x,y){
  dots0 <- as.character(substitute(alist(...)))[-1]
  vectors <- substr(dots0,1,2) == "c("
  dotsv <- dots0[vectors] %>%
    gsub("\"","",.)    %>% 
    gsub("(","('",.,fixed=TRUE)   %>% 
    gsub(", ","', '",.,fixed=TRUE)  %>%
    gsub(")","')",.,fixed=TRUE)  %>%
    map(~eval(parse(text=.x)))
  setNames(c(as.list(dots0[!vectors]),dotsv),names(pryr::dots(...)))
}

identical(my_fun2("a",foo= "b == 3",c("c","d"),bar = c("e","f"),c("g","h")),
my_fun2("a",foo= b == 3,c("c","d"),bar = c("e",f),c(g,h)))
# [1] TRUE

# [[1]]
# [1] "a"
# 
# $foo
# [1] "b == 3"
# 
# [[3]]
# [1] "c" "d"
# 
# $bar
# [1] "e" "f"
# 
# [[5]]
# [1] "g" "h"