class MegaGreeter attr_accessor :names # Create the object def initialize(names = "World") @names = names end # Say hi to everybody def say_hi if @names.nil? puts "..." elsif @names.respond_to?("each") # @names is a list of some kind, iterate! @names.each do |name| puts "Hello #{name}!" end else puts "Hello #{@names}!" end end # Say bye to everybody def say_bye if @names.nil? puts "..." elsif @names.respond_to?("join") # Join the list elements with commas puts "Goodbye #{@names.join(", ")}. Come back soon!" else puts "Goodbye #{@names}. Come back soon!" end end end if __FILE__ == $0 mg = MegaGreeter.new mg.say_hi mg.say_bye # Change name to be "Zeke" mg.names = "Zeke" mg.say_hi mg.say_bye # Change the name to an array of names mg.names = ["Albert", "Brenda", "Charles", "Dave", "Englebert"] mg.say_hi mg.say_bye # Change to nil mg.names = nil mg.say_hi mg.say_bye endIt's nice and concise, however it doesn't stand out as much as before. My comparison was Java, Tcl and Perl a few years ago. I then did a quick copy and paste, translated it to Scala.
class MegaGreeter(var names: Any = List("World")) { def say_hi { names match { case null => println("...") case listOfNames: List[String] => listOfNames foreach (n => println("Hello " + n)) case _ => println("Hello " + names) } } def say_bye { names match { case null => println("...") case listOfNames: List[String] => println("Goodbye " + listOfNames mkString(",") + ". Come back soon!") case _ => println("Goodbye " + names + ". Come back soon!") } } } object MegaGreeter { def main(args: Array[String]) { val mg = new MegaGreeter mg.say_hi mg.say_bye // Change name to be "Zeke" mg.names = "Zeke" mg.say_hi mg.say_bye // Change the name to an array of names mg.names = List("Albert", "Brenda", "Charles", "Dave", "Englebert") mg.say_hi
mg.say_bye // Change to nil mg.names = null mg.say_hi mg.say_bye } }Above is not really Scala idiomatic, but close to the original Ruby code especially how the class is created and used. Ruby still looks nice, but not as shiny as a few years ago. I am not here to say Scala is better than Ruby, but more of what is shiny before may not be as shiny today. Just like Java was shiny when I first time used it about 1996, it seems these days people see Java as the wart language. Scala will loose its shiny appeal in the next few years too.
I also been using the term "shiny", as its really about appeal. I still use Java and occasionally Perl, even if the are not shiny anymore. These older languages are still great in their own right. C is still cool these days.. I think.
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