WordBoundaries: Word boundaries

In rebus.base: Core Functionality for the 'rebus' Package

Description

BOUNDARY matches a word boundary. whole_word wraps a regex in word boundary tokens to match a whole word.

Usage

BOUNDARY

NOT_BOUNDARY

whole_word(x)

Arguments

x	A character vector.

Format

An object of class regex (inherits from character) of length 1.

Value

A character vector representing part or all of a regular expression.

References

http://www.regular-expressions.info/wordboundaries.html and http://www.rexegg.com/regex-boundaries.html

See Also

ALPHA, BACKSLASH, START

Examples

BOUNDARY
NOT_BOUNDARY

# Usage
x <- c("the catfish miaowed", "the tomcat miaowed", "the cat miaowed")
(rx_before <- BOUNDARY %R% "cat")
(rx_after <- "cat" %R% BOUNDARY)
(rx_whole_word <- whole_word("cat"))
stringi::stri_detect_regex(x, rx_before)
stringi::stri_detect_regex(x, rx_after)
stringi::stri_detect_regex(x, rx_whole_word)

Example output

<regex> \b
<regex> \B
<regex> \bcat
<regex> cat\b
<regex> \bcat\b
[1]  TRUE FALSE  TRUE
[1] FALSE  TRUE  TRUE
[1] FALSE FALSE  TRUE

rebus.base documentation built on May 2, 2019, 5:14 a.m.