R中的操作超载 [英] Operation overloading in R

问题描述

为字符重载 +的最直接方法是什么？
我已经定义了'％+％'<-function（...）paste（...，sep =）：

What's the most straight forward way of overloading '+' for characters? I have defined '%+%' <- function(...) paste(...,sep=""):

str <- "aa"%+%"bb"%+%"cc" #str="aabbcc"

但是我不喜欢这种语法。我认为 str<- aa + bb + cc 会更好。

But I don't like the syntax. I think str <- "aa"+"bb"+"cc" would be nicer.

（我正在构建用于RODBC的长SQL查询，通常的 paste 在这种情况下不是很方便。有什么建议吗？）

(I am building long SQL queries to use with RODBC, the usual paste is not very handy in such situations. Any suggestions?)

推荐答案

我认为使用两个参数比点更好：

I think that using two arguments is better than the dots:

'%+%' <- function(x,y) paste(x,y,sep="")

"a"%+%"b"%+%"C"
[1] "abC"

如果您确实要覆盖 + ，但是在执行此操作时要小心，因为这样会破坏R中最重要的功能之一。我可以没想到您为什么要超过％+％：

If you really really want to you can overwrite +, but be veeeeery careful when doing this as you will break one of the most important functions in R. I can't think of any reason why you would want to do that over %+%:

# '+' <- function(x,y) paste(x,y,sep="")
# "a"+"b"+"C"
# [1] "abC"

rm('+')

对此发表了评论确保我不会意外破坏某人R：）

commented it out to be sure I don't accidently break someones R:)

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