递归地将列表变量发送到全局环境

Question

考虑以下嵌套列表nest.

nest <- list(
    A = list(w = 1:5, x = letters[1:5]),
    B = list(y = 6:10, z = LETTERS[1:5])
)

我想将所有个别变量发送nest到全局环境中.也就是说,列表A和B和载体w,x,y,和z都应该去全球环境.以下是我的一些尝试以及他们的结果.请注意,所有这些只会将一些变量发送到全局环境.

list2env(nest, .GlobalEnv)
ls()
# [1] "A"    "B"    "nest"
list2env(unlist(nest, recursive = FALSE), .GlobalEnv)
ls()
# [1] "A.w"  "A.x"  "B.y"  "B.z"  "nest"
lapply(nest, list2env, envir = .GlobalEnv)
ls()
# [1] "nest" "w"    "x"    "y"    "z"   
with(nest, list2env(mget(ls()), .GlobalEnv))
ls()
# [1] "A"    "B"    "nest"

我也尝试了其他递归的可能性并得到错误,因为当list2env点击列表的底部时,它发现它x不是列表.

rapply(nest, list2env, envir = .GlobalEnv)
# Error in (function (x, envir = NULL, parent = parent.frame(), 
#   hash = (length(x) >  : first argument must be a named list
with(nest, {
    obj <- mget(ls())
    do.call(list2env, c(obj, envir = .GlobalEnv))
})
# Error in (function (x, envir = NULL, parent = parent.frame(), 
#     hash = (length(x) >  : unused arguments (A = list(w = 1:5, 
#     x = c("a", "b", "c", "d", "e")), B = list(y = 6:10, 
#     z = c("A", "B", "C", "D", "E")))

如何递归调用list2env以便所有变量都进入全局环境？从一个新的R会议,ls()将导致

# [1] "A" "B" "nest" "w" "x" "y" "z"

我也尝试过,local并遇到同样的问题.

Answer 1

使用递归函数.不优雅,但似乎工作:

nest <- list(A = list(w = 1:5, x = letters[1:5]),
             B = list(y = 6:10, z = LETTERS[1:5]))

test <- function(x) {
    if(is.list(x)) { 
        list2env(x, envir = .GlobalEnv)
        lapply(x, test)
    }
}

test(nest)
ls()
# [1] "A"    "B"    "nest" "test" "w"    "x"    "y"    "z"