Ruby CSV, using square brackets as row separators

Question

I'm trying to use square brackets '[]' as a row separator in a CSV file. I must use this exact format for this project (output needs to match LEDES98 law invoicing format exactly).

I'm trying to do this:

CSV.open('output.txt', 'w', col_sep: '|', row_sep: '[]') do |csv|
     #Do Stuff
end

But Ruby won't take row_sep: '[]' and throws this error:

lib/ruby/1.9.1/csv.rb:2309:in `initialize': empty char-class: /[]\z/ (RegexpError)

I've tried escaping the characters with /'s, using double quotes, etc, but nothing has worked yet. What's the way to do this?

Answer 1

The problem is in CSV#encode_re: the parameter row_sep: "|[]\n" is converted to a Regexp.

What can redefine this method:

class CSV
  def encode_re(*chunks)
    encode_str(*chunks)
  end
end
CSV.open('output.txt', 'w', col_sep: '|', row_sep: "|[]\n"
  ) do |csv|
   csv << [1,2,3]
   csv << [4,5,6]
end

The result is:

1|2|3|[]
4|5|6|[]

I found no side effect, but I don't feel comfortble to redefine CSV, so I would recommend to create a new CSV-variant:

#Class to create LEDES98
class LEDES_CSV < CSV
  def encode_re(*chunks)
    encode_str(*chunks)
  end
end
LEDES_CSV.open('output.txt', 'w', col_sep: '|', row_sep: "|[]\n"
  ) do |csv|
   csv << [1,2,3]
   csv << [4,5,6]
end

Then you can use the 'original' CSV and for LEDES-files you can use the LEDES_CSV.