Perl regular expressions in the stringr package

Question

The perl() function is deprecated in the latest version of stringr in favor of regex(). However, I don't seem to be able to replicate the earlier behavior.

To capitalize the first letter of a vector of strings, this used to work:

name <- c("jim", "john", "bill")
str_replace(name, perl("^(.)"), "\\U\\1")

However, this no longer works:

str_replace(name, regex("^(.)"), "\\U\\1")

But using base R works:

gsub("^(.)", "\\U\\1", name, perl=TRUE)

Is there still a way to do this with the stringr package?

It now uses stringi to actually do the work. Just use `gsub` directly if you want perl regex's. — G. Grothendieck, May 13 '15 at 15:17

hwnd · Accepted Answer · 2017-05-25T03:03:45.357

7

stringr is now powered by stringi instead which uses ICU regular expressions. If you want to implement PCRE, simply use sub directly while turning on perl = TRUE mode ...

sub('^(.)', '\\U\\1', name, perl=TRUE)
[1] "Jim"  "John" "Bill"

edited May 25 '17 at 03:03

answered May 13 '15 at 18:06

hwnd

69,796
4
95
132

4

So there is no option whatsoever to use PCRE with stringr? – kath May 13 '18 at 12:19
1

tha'ts a dealbreaker, I'd say – emilBeBri Apr 29 '21 at 06:07

Perl regular expressions in the stringr package

1 Answers1

Linked