Anchors                 The start or end of a string
Backreferences          Backreferences
CharacterClasses        Class Constants
ClassGroups             Character classes
Concatenation           Combine strings together
DateTime                Date-time regexes
IsoClasses              ISO 8601 date-time classes
ReplacementCase         Force the case of replacement values
SpecialCharacters       Special characters
Unicode                 Unicode classes
UnicodeGeneralCategory
                        Unicode General Categories
UnicodeOperators        Unicode Operators
UnicodeProperty         Unicode Properties
WordBoundaries          Word boundaries
as.regex                Convert or test for regex objects
capture                 Capture a token, or not
char_class              A range or char_class of characters
escape_special          Escape special characters
exactly                 Make a regex exact
format.regex            Print or format regex objects
get_weekdays            Get the days of the week or months of the year
literal                 Treat part of a regular expression literally
lookahead               Lookaround
modify_mode             Apply mode modifiers
number_range            Generate a regular expression for a number
                        range
or                      Alternation
rebus                   rebus: Regular Expression Builder, Um,
                        Something
recursive               Make the regular expression recursive.
regex                   Create a regex
repeated                Repeat values
roman                   Roman numerals
whole_word              Match a whole word
