R:我可以更新 magrittr 管道中对象的类吗? [英] R: can I update the class of a an object in a magrittr pipe?

问题描述

我有一段代码用于更新对象的类.但是我必须打破代码的跟随才能分配课程.是否有一种优雅的方式来分配课程但继续管道，所以我有一个管道一直到最终结果?我怀疑 {purrr} 中可能有什么东西?

I have a piece of code where I update the class of the object. But I have to break the follow of the code to assign the class. Is there an elegant to to assign the class but continue the pipe so I have one pipe all the way to the final result? I suspect there might be something in {purrr}?

library(disk.frame)
library(dplyr)
library(tidyquery)

a = nycflights13::airports %>%
  as.disk.frame

class(a) <- c(class(a), "data.frame")

a %>% 
  query("SELECT name, lat, lon ORDER BY lat DESC LIMIT 5")

推荐答案

当然，你可以使用 "class<-"():

library(dplyr)

x <- 1:10 %>%
    "class<-"("foo")
x
#  [1]  1  2  3  4  5  6  7  8  9 10
# attr(,"class")
# [1] "foo"

详情

通常，在 R 中，当您可以分配给函数的输出时，例如class(x) <- "foo"，你使用的是替换函数"，例如"class<-"().可以在此处找到有关 Stack Overflow 上对此的详细讨论.

Details

Generally, in R, when you can assign to a function's output, e.g. class(x) <- "foo", what you're using is a "replacement function", e.g. "class<-"(). A good discussion of this on Stack Overflow can be found here.

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