rx_maybe: Optionally match an expression.

Description Usage Arguments References Examples

Description

This expression uses a quantifier ? to optionally match things. Specifically, the question mark makes the preceding token in the regular expression optional.

Usage

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rx_maybe(.data = NULL, value)

Arguments

.data

Expression to append, typically pulled from the pipe %>%

value

Expression to optionally match

References

Quantifiers: https://www.regular-expressions.info/optional.html

Examples

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rx_maybe(value = "abc")

# create expression
x <- rx_start_of_line() %>%
  rx_maybe("abc") %>%
  rx_end_of_line(enable = FALSE)

grepl(x, "xyz") # should be true

VerbalExpressions/RVerbalExpressions documentation built on May 14, 2019, 11:02 p.m.