re = /\w+(?:,\s*\w+(?:\s+and\s+\w+)?)+,?\s*(and|or)/m
str = 'a, b, c and d, or e
a, b, c and d, or e but not f, g, h and i, or j
'
# 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