re = /(?'a'[~_])(?=
(?'d'(?!\s)(?:(?!\k'a').)+(?<!\s)\k'a') |
(?=(?'b'.*))(?'c'
^(?>\k'a'(?&d)|.)*\k'a'(?&d)(?=\k'b'\z) |
(?<=(?=x^|(?&c)).)
)
)/x
str = '~target~
~target~adjacent is not target~
begining with space ~ target~
ending with space ~target ~
empty ~~
divided by two lines _tar
get_
without closing delimiter ~target
with mixed delimiters ~_target~_
with nested delimiters ~_target_~'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html