Ruby regexp: complex pattern

Question

I have a number of possible patterns for title which I want to capture using Ruby regexp.

1. Just title
2. Ignore | The title to capture
3. Ignore / The title to capture
4. [Ignore] The title to capture

How do I put this into one regexp pattern?

This method deals with the 2nd case only:

  def self.format_title(title)
    title.match(/(?:.+)\|(.+)/).to_a.first.strip
  end

Answer 1

Your code can be rewritten into: title[/\|(.+)/),1].strip

And for all four cases I recommend to use gsub:

def format_title title
    title.gsub(/.+[\|\/]/,'').gsub(/^\[.+\]/,'').strip
end

Answer 2

Try this regular expression:

/^(?:[^|]*\||[^\/]*\/|\[[^\]]*\])?(.+)/

The optional non-capturing group (?:[^|]*\||[^\/]*\/|\[[^\]]*\]) consists of a pattern for each case:

• [^|]*\| matches everything up to the first |,
• [^\/]*\/ matches everything up to the first /, and
• \[[^\]]*\] matches everything between [ and the first following ] at the begin of the string