re = /(?<!\S)programming language(?![^\s.!?])|(?<!\S)programming(?![^\s.!?])|(?<!\S)language(?![^\s.!?])/
str = 'A programming language is a formal language that specifies a set of instructions that can be used to produce various kinds of output. programming languages generally consist of instructions for a computer.'
# 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