camel and snake casing

thread_safe_camel_snake.rb

def camel_case( string )  
  string.split('_').map do |word|
    "#{word.slice(/^\w/).upcase}#{word.slice(/^\w(\w+)/, 1)}"
  end.join
end

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