recursive {rebus.base} | R Documentation |
Makes the regular expression (or part of it) recursive.
recursive(x)
x |
A character vector. |
A character vector representing part or all of a regular expression.
Recursion is not supported by R's internal PRCE engine or
stringi
's ICU engine.
http://www.regular-expressions.info/recurse.html and http://www.rexegg.com/regex-recursion.html
recursive("a") # Recursion isn't supported by R's PRCE engine or # stringi/stringr's ICU engine x <- c("ab222z", "ababz", "ab", "abab") rx <- "ab(?R)?z" grepl(rx, x, perl = TRUE) try(grepl(rx, x)) try(stringi::stri_detect_regex(x, rx))