在分隔符上拆分字符串，在拆分前保留分隔符

Question

问题R split on delimiter (split) keep the delimiter (split)的明显延伸是： 如何拆分字符串，使分隔符保持在每个部分的开头？

x <- "What is this?  It's an onion.  What! That's| Well Crazy."

解决方案

unlist(strsplit(x, "(?<=[?.!|])", perl=TRUE))

给出：

"What is this?"    "  It's an onion." "  What!" " That's|" " Well Crazy."

我正在寻找：

"What is this"    "? It's an onion" ".  What" "! That's" "| Well Crazy."

将积极的外观转变为积极的前瞻并不能解决问题。

Answer 1

我设法使用正向前瞻，然后是单词边界标记来解决它：

x <- "What is this?  It's an onion.  What! That's| Well Crazy."
strsplit(x, "(?=[?.!|].)\\b", perl=TRUE)

[1] "What is this"     "?  It's an onion" ".  What"          "! That's"        
[5] "| Well Crazy."

Demo