在 R 中使用表情符号

我有一个包含很多表情符号的 csv 文件：

Person, Message,
A, ????,
A, How are you?,
B, ???? Alright!,
A, ????????

我怎么能够read.csv()进入 R 以便表情符号不会变黑？

（我想跟踪一段时间内表情符号的使用情况????）

我的控制台有一种接受这些“字符”的字体：

  txt <- "Person, Message,
 A, ????,
 A, How are you?,
 B, ???? Alright!,
 A, ????????"

 Encoding(txt)
#[1] "UTF-8"
 dput(txt)
#"Person, Message,\nA, \U0001f609,\nA, How are you?,\nB, \U0001f64d Alright!,\nA, \U0001f483\U0001f483"

> tvec <- scan(text=txt, what="")
Read 13 items
> dput(tvec)
c("Person,", "Message,", "A,", "\U0001f609,", "A,", "How", "are", 
"you?,", "B,", "\U0001f64d", "Alright!,", "A,", "\U0001f483\U0001f483"
)

> which(tvec == '\U0001f609,')
[1] 4

当我使用 scan 使用逗号 sep 读取该文本时，前导空格阻止了相等测试成功，但如果我使用两个字符版本，则成功：

> which(tvec == '\U0001f609')
integer(0)
> dput(tvec)
c("Person", " Message", "", "A", " \U0001f609", "", "A", " How are you?", 
"", "B", " \U0001f64d Alright!", "", "A", " \U0001f483\U0001f483"
)
> which(tvec == " ????")
[1] 5

这是使用 Courier New 作为 Mac 上的控制台/编辑器字体。要查看 Unicode 表示形式的解释，请参阅?Quotes {base}.