如何指定操作符%+%的库(如pkg:：或pkg：)

Question

运算符%+%在两个包中使用，即ggplot2和crayou。

函数%+%在crayon中有时不能工作，我认为操作符%+%在ggplot2中是考虑的。我试图通过crayon::%+%进行标识，但这不起作用。

cat(green(
 'I am a green line ' %+%
 blue$underline$bold('with a blue substring') %+%
 ' that becomes green again!'
))

--根据评论:我认为我的理解出现了以下错误

我尝试使用crayon::(backtick)%+%(backtick)而不是%+%运行以下代码

cat(green(
    'I am a green line ' crayon::`%+%`
        blue$underline$bold('with a blue substring') crayon::`%+%`
        ' that becomes green again!'
))

但会发生以下错误：

  > cat(green(
+     'I am a green line ' crayon::`%+%`
Error: unexpected symbol in:
"cat(green(
    'I am a green line ' crayon"
>         blue$underline$bold('with a blue substring') crayon::`%+%`
Error: unexpected symbol in "        blue$underline$bold('with a blue substring') crayon"
>         ' that becomes green again!'
[1] " that becomes green again!"
> ))
Error: unexpected ')' in ")"

Answer 1

一种选择是不使用library(crayon)或requireNamespace(crayon)，完全限定所有crayon引用：

cat(crayon::green(
  'I am a green line ' %c+%
    crayon::blue$underline$bold('with a blue substring') crayon::`%+%`
    ' that becomes green again!'
))

不过，这很烦人。因此，您也可以手动导入和重命名所需的东西，而不需要单独的非核心包。

`%c+%` <- getFromNamespace("%+%", "crayon") # changed to not break other things
green <- getFromNamespace("green", "crayon")
blue <- getFromNamespace("blue", "crayon")

cat(green(
  'I am a green line ' %c+%
    blue$underline$bold('with a blue substring') %c+%
    ' that becomes green again!'
))