Ruby script to convert CamelCase and snake_case each other.

conv_camel_snake.rb

class String
  def to_camel
    self.split(/_/).map(&:capitalize).join
    # or
    #self.split(/_/).map{ |w| w[0] = w[0].upcase; w }.join
  end

  def to_snake
    self.gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
        .gsub(/([a-z\d])([A-Z])/, '\1_\2')
        .downcase
  end
end

src = "CamlCase1ASnakeCase2B"
puts "  SRC: #{src}"
snake = "CamlCase1ASnakeCase2B".to_snake
puts "SNAKE: #{snake}"
camel = snake.to_camel
puts "CAMEL: #{camel}"