re = /# https:\/\/regex101.com\/r\/fP1oQ6\/2
(?(DEFINE)#
(?<W>\s*)
(?<V>\d+(?:\.\d+)?(?&W))
(?<S>[-+]?)
(?<O>(?&W)[-+*\/](?&W))
(?<E>(?&S)(?:(?&V)|\((?&W)(?&E)(?&W)\))(?:(?&O)(?&E))?)#
)#
((?&E))/x
str = '(8 - 1 + 3) * 6 - ((3 + 7) * 2)'
# 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