re_match {rematch}

Match a regular expression to a character vector

Description

This function is a small wrapper on the regexpr base R function, to provide an API that is easier to use.

Usage

re_match(pattern, text, ...)

Arguments

pattern

Regular expression, defaults to be a PCRE expression. See regex for more about regular expressions.

text

Character vector.

...

Additional arguments to pass to regexpr.

Details

Currently only the first occurence of the pattern is used.

Value

A character matrix of the matched (sub)strings. The first column is always the full match. This column is named .match. The result of the columns are capture groups, with appropriate column names, if the groups are named.

Examples

dates <- c("2016-04-20", "1977-08-08", "not a date", "2016",
  "76-03-02", "2012-06-30", "2015-01-21 19:58")
isodate <- "([0-9]{4})-([0-1][0-9])-([0-3][0-9])"
re_match(text = dates, pattern = isodate)

# The same with named groups
isodaten <- "(?<year>[0-9]{4})-(?<month>[0-1][0-9])-(?<day>[0-3][0-9])"
re_match(text = dates, pattern = isodaten)